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Study Unit

Metal FinishingBy

Reid Coffield

Copyright © 1998 by Education Direct, Inc.

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About the Author

Reid Coffield grew up in the foothills of western North Carolina. One of Reid’s earliest memories

was of watching his great uncle, a World War I veteran, disassemble and reassemble his Luger

pistol. From that moment, Reid was hooked! His family encouraged his interest and kept him

well supplied with firearm-related books. By the time he was a teenager, he was swapping guns,

fixing them up, and trading them for other guns. Herebarreled his first centerfire rifle when he

was only 16. He went on to graduate from the University of North Carolina at Chapel Hill and

later earned a graduate degree. Along the way he spent four years in the United States Air

Force, serving time in Asia and Europe.

After military service, Reid worked for the county government, but found that he spent more

and more of his time repairing firearms. Eventually, he enrolled in the Colorado School of

Trades and began a full-time gunsmithing career. He had his own shop for many years before

joining the staff at Brownells, where he is currently the senior Technical Support Staff member.

His specialty areas are metal finishing, with an emphasis on bluing and rifle work.

Reid is actively involved in competitive shooting and is a regular participant in the National

Matches at Camp Perry. Reid is a service rifle shooter and currently holds a Master class rating

from the NRA. Reid is primarily a small-game hunter and he prefers to use a muzzleloader for

hunting. He also has a modest collection of World War I firearms, which includes his great

uncle’s Luger.

iii

First, we’ll address in this unit the purpose

for metal finishing. Second, a brief historical

account of metal finishing precedes discus-

sion on the issue of refinishing vs restoration.

Next addressed is the effect of refinishing

on a firearm’s value. Then, we’ll present several commonly

encountered types of metal finishing procedures. Lastly, the

section “Offering Refinishing Services” contains many useful

tips for making your refinishing operation a success.

When you complete this study unit, you’ll be able to Present a brief history of metal finishing

• Differentiate between refinishing and restoration

• Recognize the various types of metal finishes

• Identify the equipment necessary for metal finishing

• List safety procedures relevant to metal finishing

• Describe proper methods of metal preparation for metal finishing

• Explain procedures for accomplishing several types of metalfinishing

• List ways to market your metal finishing services

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INTRODUCTION TO METAL FINISHING 1

Purpose of Finishing 1The History of Metal Finishing 2Refinishing vs. Restoration 5The Effect of Refinishing on the Value of a Firearm 7

COMMON FINISHES 10

Black Oxide or Caustic Salt Bluing 10Hot Water or Accelerated Rust Bluing 13Traditional Rust Bluing 14Nitre Bluing 16Browning 17Electroless Nickel Plating 18Parkerizing 19Baking Lacquer 20Flame Coloring 21Jeweling 22Cold Bluing 23Other Metal Finishes 24

THE REFINISHING SHOP AND SAFETY 29

Offering Refinishing Services 29How to Market Your Services 30Sales Aids 31Potential Problems and How to Avoid Them 33Safety 35Personal Safety Equipment and Procedures 35Material Safety Data Sheets 37

METAL PREPARATION 39

Introduction 39Disassembly 39Cleaning 42Removing Old Finishes 43Preparing the Metal 53

REFINISHING EQUIPMENT AND PROCEDURES,PART 1 61

Caustic Salt Bluing 61Hot Water or Accelerated Rust Bluing 75

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Contentsvi

REFINISHING EQUIPMENT AND PROCEDURES,PART 2 83

Traditional Rust Bluing 83Nitre Bluing 84Browning 87Electroless Nickel Plating 89Parkerizing 92Baking Lacquer 94Flame Coloring 95Jeweling 97Cold Bluing 98Conclusion 100

SELF-CHECK ANSWERS 103

EXAMINATION 105

1

INTRODUCTION TO METAL FINISHING

Purpose of Finishing

Over the centuries, various types of finishes have been

applied to metal on firearms for different reasons. A finish

may be decorative; that is, it’s aesthetically pleasing to the

builder or owner of the firearm. The finish primarily

enhances the appearance or beauty of the metal work.

A particular finish may also protect or preserve the metal.

Since most of the metal used to produce firearms will rust

or oxidize, a coating will usually prevent rust and extend the

useful life of the firearm.

Finally, a finish may add a particular quality or feature to a

firearm. For example, a hunter may choose to have a very

dull, nonreflective finish applied to his or her rifle or shotgun

so it won’t reflect light and alert or frighten the game being

stalked.

As a gunsmith, customers will often ask you about different

metal finishes. You need to have a solid understanding of dif-

ferent types of finishes commonly available and be able to

discuss the relative merits and features of each. In addition,

you may wish to offer some types of metal finishing in your

own shop. If you’re working in someone else’s shop, you may

be the one to do the metal finishing work. Because of this,

your knowledge of metal finishing is very important.

For the most part, the more commonly encountered finishes

are relatively easy to apply, and the process isn’t all that dif-

ficult to master. When it comes to metal finishing, there’s

nothing all that mysterious, and certainly nothing to be

Metal Finishing

Metal Finishing

afraid of! It’s well within the capability of the average person

to learn to apply a variety of finishes and to do so in a com-

petent, professional manner. The fact that you’re taking the

time and effort to study and learn to be a gunsmith would

indicate that more than likely you have what it takes to

do this.

In this text, we emphasis practical, useful information. We

won’t give you formulas for old, seldom-used bluing or

browning solutions. Rather, you’ll learn how to use modern,

readily available finishing solutions and materials.

The History of Metal Finishing

Protective metal finishes have been used in some form for

hundreds of years. It’s not necessary to go into great detail

regarding prenineteenth century finishing procedures or for-

mulas. For the most part, your work as a gunsmith will be

limited to dealing with firearms produced after approximately

1900. The material in this text will help you obtain the

knowledge and skills to provide metal finishes that are

suitable and correct for firearms of the post-1900 period.

No one knows for certain how metal on the first firearm was

finished or if it had any finish at all. Just as no one knows

who built the first handheld firearm, the details on the earli-

est firearm metal finishes are long since lost. We do know,

however, that from the earliest times ancient armorers and

weapons builders provided decorative and protective finishes

to swords, armor, and other metal equipment. Therefore, it’s

very likely that they applied many of these same techniques

to the earliest firearms and firearm components.

It’s safe to assume that quite early the old-time gun makers

noticed that they could control the natural tendency for metal

to rust. In fact, by monitoring how and to what degree the

exterior of a musket barrel rusted, gun makers were able to

develop an attractive and durable finish.

As it became known that armorers could use the natural

rusting process as the basis for a durable metal finish, they

began to experiment with various procedures and techniques.

Instead of simply relying on the humidity or moisture found

in the air in their shop to start the rusting, they developed

2

Metal Finishing 3

various formulas and solutions to speed up the process. Some

of these early solutions contained components such as salt-

water, urine, or blood that would quickly rust the relatively

soft metals used on the earliest firearms. There were no

universal formulas and each armorer or gunsmith had a

“secret” solution.

Aside from the rusting procedures, metal items were some-

times painted with a lacquer or coated with oils or animal

fat and then heated over a fire or in a forge. This would result

in a blue or black metal coating. While not necessarily very

durable, these finishes could look attractive.

Possibly as early as the 1600s, metal finishing had developed

to the point that metal coloring on firearms was quite com-

mon. The English referred to it as browning, while the early

Germans called it bronzing. In both cases, the roots of the

term (even at the time of the seventeenth century) went back

hundreds of years.

One misconception that many people have about early mili-

tary firearms has to do with the metal finishes. Virtually all

early military firearms produced up until the nineteenth cen-

tury were “in the white”—that is, the metal wasn’t blackened,

blued, or browned. It was left in a natural unfinished state.

The famous British Brown Bess flintlock musket used for

hundreds of years was almost always issued with unfinished

or natural metal. We don’t know the specific reason for this.

However, it was a regular and common part of every British

soldier’s routine to brighten the metal on his Brown Bess

with a bit of leather and some fine sand. British soldiers

around the world spent literally millions of hours keeping

their muskets spotless and free of rust.

It wasn’t until the time of the Civil War, from 1861 to 1864,

that the United States Army began to issue some rifles with

blued or blackened metal. The first large-scale issue of mili-

tary rifles with a bluedor blackened barrel in what is now

Germany didn’t occur until after 1871.

By the late nineteenth century, large arms manufacturing

companies that could produce thousands of guns each year

became established. Along with this came the necessity for

developing ways to quickly and easily color the metal of these

firearms. This was the real beginning of modern gun making

and metal finishing techniques.

For detailed information and formulas for some of the very

early metal finishing solutions, many consider the book

Firearm Bluing and Browning by R. H. Angier to be the stan-

dard or basic text. This book is available from Brownells,

Inc., Route 2, Box 1, Montezuma, IA 50171. You may also

obtain Angier’s book from dealers in firearm-related books

such as Rutger’s Book Center, 127 Raritan Ave., Highland

Park, NJ 08904.

Another interesting and useful source of information on

nineteenth century metal finishing is The Gunsmith’s Manual

by J. P. Stelle and William B. Harrison. Published in 1883,

this was the first American gunsmithing book. It’s still in

print and is available from Brownellsor Rutger’s Book Center.

As a gunsmith, you should obtain copies of these books for

your shop library. Like any professional, you’ll need reference

material to enable you to do research from time to time.

These books will especially help you if you go into the highly

specialized field of firearms restoration. (We cover restoration

a little later.)

It’s essential for you to understand that the old formulas and

procedures are interesting and in certain limited applications

very useful. However, for the gunsmith that works primarily

on modern firearms, these formulas have little practical use.

Most of these old formulas use archaic terms for the various

chemical compounds, which makes it difficult to locate mod-

ern chemical equivalents. (In the book Gunsmith Kinks, Vol. II,

by Bob Brownell, there are lengthy tables giving the modern

names for many of these old chemicals.)

Many of the old bluing formulas use extremely dangerous

chemicals that you should avoid at all costs. For example,

cyanide was often used in some of the older bluing solutions.

Under no circumstances should you use any formula that

contains a poison such as cyanide.

For 99.9 percent of your metal finishing work, there are

many modern, readily available metal finishing compounds

that are effective, easy to use, and a lot safer.

Metal Finishing4

Metal Finishing 5

Refinishing vs Restoration

As a gunsmith actively involved in repair and refinishing,

you’ll almost certainly face the problem of deciding if certain

work is appropriate for a particular firearm. A few folks who

do gun work will repair or refinish anything that comes into

their shops, old or new, common or rare. Their feeling is that

if the owner wants the work done, they’ll do it, period! Often

some of these fellows will characterize themselves as doing

“restoration” work.

The problem with this approach is that these folks are doing

a disservice to themselves, their customers, and the guns

they work on. More often than not, they make problems

worse.

For example, consider this incident. A certain man had an

original, signed, North Carolina-made muzzle-loading rifle

that had been in his family for generations. He had allowed

a gunsmith to “fix it up.” The gunsmith, who wasn’t knowl-

edgeable about nineteenth century firearms, had overpolished

the octagon barrel, giving it a very high-gloss, caustic salts

finish. In the process, he had rounded off the edges of the

barrel flats. He replaced the original wood ramrod with one

made of steel because he said “it was stronger and wouldn’t

break like the old one.” And he had dressed up the stock with

a series of crudely done brass inlays. The rifle was ruined. It

had lost not only its monetary value, but its historical value

as well.

This was not restoration. This was a case of careless and

thoughtless refinishing. Restoration means to return an item

to an earlier state and to stop further deterioration. Ideally,

restoration should employ only those techniques and materi-

als that the original maker used. In restoration, no work

should be done that could not successfully beredone or

reversed later—say 50 to 100 years later.

If you’re going to restore a gun that was originally rust blued,

you shouldn’t reblue it with a caustic salt. If the gun has

inlays held with handmade screws or a glue made of animal

hide, you shouldn’t use machine screws and epoxy. If the

wood finish was originally a form of varnish, then you should

duplicate that original formula for the finish.

Restoration in this sense isn’t for the inexperienced. There

are probably fewer than 100 people in the United States real-

ly qualified to do true restoration work. Such people have

spent years studying a particular type of firearm and don’t

work on anything else. Restoration is a very specialized field,

and most restoration people work for large museums.

You don’t need to feel pressured to become an expert in

restoration. There are more than enough hunting and sport-

ing firearms that aren’t collectibles to keep you busy for

several lifetimes. Although you may not be a collector and

you may not deal in collectible firearms, it’s important that

you have some general knowledge about which guns you

should and shouldn’t refinish.

As you build your library on firearms, add some books on gun

collecting (Figure 1). Norm Flayderman’s Guide to Antique

American Firearms is an excellent reference source. As you

visit gun shows, stop and talk with the dealers in collectibles.

Get to know collectors in your own community. Most collectors

are eager to talk about their hobby. They’ll help keep you

from mistakenly doing something to a firearm that might

not be in your best interest. And don’t forget, these folks

are also potential customers. Most gun collectors own some

noncollectibles as well.

Metal Finishing6

FIGURE 1—A good referencelibrary can be asimportant anduseful to a gunsmith as anytool in his or her shop.

Metal Finishing 7

The Effect of Refinishing on the Value ofa Firearm

Many years ago, a gunsmith maintained that no one should

do work to a firearm that would lower its value. This is a

good rule for you to follow. If you violate it, it may cause you

a great deal of trouble and may even severely damage your

reputation.

I remember very clearly having a fellow come into my shop

and ask if I did rebluing. I responded that I did and showed

him some samples of my work. He then pulled a Colt Single-

Action Army revolver out of a case and told me that he wanted

it reblued.

I carefully examined the revolver, which was made around

1900. It still had about 70 percent of its original finish and

showed no signs of abuse. All the lettering was in good shape,

and the screw slots weren’t burred.

The customer got a bit impatient and finally asked what was

wrong. I explained that he had a very nice original Colt that

at that time was worth about $600.00. If I were to reblue it

and do an absolutely flawless job, the value of the gun would

be reduced to about $300.00 at most. Because of that, I

would not take the job.

To say that this fellow was upset would be an understatement!

I tried to explain why I couldn’t reblue his gun. Sure, he

owned it and yes, he might never sell it, so perhaps value

meant nothing. But someday, that gun would move on to

another owner, and I didn’t want to be part of ruining a good

collectible. It was also important to me that none of my other

customers, present and future, would ever think that I had,

in effect, ruined a collectible gun. I might lose this one job

now, but if I took it and the word got out that I had

“butchered” a nice gun, no one knows how many jobs it

would have cost me.

I never did soothe this fellow’s ruffled feathers. He left the

shop in a huff, but he was the exception. The majority of

folks who had collectible guns and wanted major refinishing

work done to them were very pleased—and thankful—when

I informed them of what they had, even though it meant that

I might not do the job they requested. Time after time, these

customers brought me other guns to work on and helped by

telling their friends of my shop.

Does this mean you should never reblue a gun? Of course

not. It just means you should consider the effect of your

work on a particular gun. A well-worn, rusty Remington 870

will probably go up in value after you give it a good reblue

job. This is true for most common hunting and sporting

guns. It’s only the collectibles about which you should con-

cern yourself.

As mentioned earlier, you’ll need to learn which guns are

considered collectibles and which are not. It won’t take long.

Keep your eyes and ears open at gun shows, talk with other

dealers, read the ads in Shotgun News and The Gun List.

Make an effort to become knowledgeable in this area, both

for the sake of your reputation, as well as the benefit of your

customers.

Metal Finishing8

Metal Finishing 9

Self-Check 1

At the end of each section of Metal Finishes, you’ll be asked to pause and check your under-standing of what you have just read by completing a “Self-Check” exercise. Answering thesequestions will help you review what you’ve studied so far. Please complete Self-Check 1 now.

1. Why is it important to know about different metal finishes?

__________________________________________________________________________

2. What type of finish was used on the first firearm?

__________________________________________________________________________

3. Did all early gunsmiths use the same type of protective metal finish?

__________________________________________________________________________

4. What type of metal finish did most prenineteenth century military firearms have?

5. What book contains formulas for early metal finishes for firearms?

__________________________________________________________________________

6. What book should you add to your shop library as a basic guide to antique and collectible firearms?

__________________________________________________________________________

7. When asked to do work on a collectible firearm, what’s a good rule of thumb to guideyour response?

__________________________________________________________________________

Check your answers with those on page 103.

COMMON FINISHES

Before studying specific metal finishing procedures, you

should look briefly at the commonly encountered types of fin-

ishing. Again, as a gunsmith, you can expect to have your

friends and customers ask you for information and advice

about metal finishes. It’s important that you be aware of

some of the basic aspects of each type. Later we’ll go into

detail regarding those finishing procedures that you’ll proba-

bly use in your shop.

Black Oxide or Caustic Salt Bluing

When most folks talk about gun bluing by a professional

gunsmith or a gun factory, they’re usually talking about a

black oxide coating. This coating, which has been in use since

around 1900, is created by the action of a chemical mixture,

typically sodium hydroxide, sodium nitrite, and sodium nitrate.

These chemicals are mixed together in specific proportions

and added to a tank of heated water. The normal operating

temperature for this solution can range from approximately

285 to 315°F (degrees Fahrenheit). A variety of companies,

such as Du-Lite, Parks, and Brownells, sell the commercial

salts of this type.

There are several advantages to using a black oxide salt.

1. It’s relatively quick and easy to use.

2. It provides a uniform color on most chromemoly steels.

3. The resulting black finish is durable and attractive.

It’s by far the most commonly used finish in the gun industry

today.

To offer a black oxide finish, you must have a number of

heated tanks, special cleaners, a bluing area separate from

your regular shop area, and a good ventilation system. Due

to the caustic nature and high operating temperatures of the

salts solution, you must take great care when working with

it. Carelessness can result in severe burns from the solution.

Metal Finishing10

Metal Finishing 11

You can’t use the salts solution on aluminum or copper. It

would quickly eat away an aluminum receiver, such as that

found on a Mossburg Model 500 or Winchester Model 1200

shotgun. In addition, most caustic salts solutions sold for

bluing firearms won’t blue stainless steel, which requires

special solutions.

You should never use caustic salts solutions on any firearm

with soft-soldered components. For example, most older side-

by-side, double-barrel shotguns were constructed with ribs

that hold the barrels together. These ribs are usually soft

soldered in place.

Although some gunsmiths use caustic salts to blue these

old doubles, my advice is don’t. The salts will attack the lead

in the solder and can cause the ribs to separate. This can

happen during the bluing process or even years after the

gun was blued. I have had more than one nice old double

brought into my shop with a separated rib because someone

blued the gun with a caustic salt.

How can you identify those guns with soft-soldered ribs?

Unfortunately, there’s no list available, but there are some

guidelines to help you know what guns you can appropriately

blue with caustic salts. Virtually all doubles made prior to

World War II are soft-soldered. This includes, but is not lim-

ited to, Parker, L. C. Smith, A. H. Fox, Ithaca, and Lefever

shotguns. A simple way to determine if a soft solder has been

used to join the barrels is to look at the end of the barrels at

the muzzle. You can usually see a line of solder where the ribs

join the barrels. Take a sharp scribe and carefully scratch this

joint line. If the solder is a soft or lead-based solder, it will

easily dent or scratch. A hard or silver solder will resist

marking.

A simple rule of thumb about bluing (and gunsmithing work

in general) that can keep you out of trouble is this: “If in

doubt, don’t!” You may occasionally miss out on a bluing job,

but you’ll never face the embarrassing and financially painful

situation of buying a gun you accidentally ruined.

Another gun that you can’t blue with normal caustic salts

is the lever-action Winchester 94, manufactured after 1964.

At that time, Winchester developed a casting for the receiver,

which could not be blued in the traditional manner. Over the

years, Winchester has used a variety of plating finishes on

these cast receivers. Occasionally a customer will bring you

one of these 94s for you to reblue. It’s probably best to turn

the job down. You can apply certain types of finishes to these

rifles, but a standard caustic salt simply won’t work. The 94s

you should avoid, by the way, are those with serial numbers

above approximately 2,700,000.

When discussing the appropriateness of caustic salt bluing

with your customers, you should point out that while the

black oxide coating will provide some degree of rust protection,

it won’t totally prevent rusting. They must still clean, oil,

and give proper maintenance to a blued firearm to prevent

corrosion.

The abrasion resistance or wearability of black oxide finish

is primarily a function of the way in which the base metal

was prepared. For example, a barrel with a mirrorlike polish

prior to bluing won’t resist bluing wear as one that was

sandblasted and then blued.

While we refer to the process and the finish as bluing, in

most cases the color of the finish resulting from use of a

caustic salt will be black or some shade of black. This is

true of virtually all commercial bluing salts presently available.

Because it takes only 30 minutes to an hour to apply a finish

of this type after you prepare the metal, it’s normally fairly

inexpensive. Compared to some of the old traditional slow

rust blues that took days or weeks to apply, the caustic salt

solutions are extremely fast and consequently more affordable.

As you progress in your career as a gunsmith, you’ll probably

offer black oxide metal finish in your shop. With the modern

premixed solutions and the technical support available from

gunsmith suppliers, caustic salt bluing is nothing to be afraid

of or avoided. Tens of thousands of gunsmiths over the years

have learned to apply this finish. Those who can follow direc-

tions, observe some basic safety rules, and are careful about

their work can safely and easily apply black oxide or caustic

salt bluing.

Metal Finishing12

Metal Finishing 13

Hot Water or Accelerated Rust Bluing

We can think of the currently available hot water bluing

solutions, such as Belgian Blue and Brownells’ Dicropan IM,

as modern derivatives of the old traditional rust blues. Such

modern finishes aren’t technically rust blue, but are chemically

more closely related to some of the commonly encountered

cold blues.

In terms of durability and abrasion resistance, the hot water

blues are normally tougher and stronger than the caustic

salt solutions and are basically equivalent in these respects to

the traditional rust blues. Normally, the metal isn’t polished

beyond 400 grit when you use this process. In fact, you may

give most metal components a light acid etching. This often

provides for better adhesion of the hot water bluing solution.

The color of this type of finish will in most cases have a bluish

cast. It’s not the black color that you find with caustic salts.

For this reason alone you’ll have many customers who prefer

this type of finish.

Unlike caustic salt solutions, the hot water blues won’t have

any negative effect upon soft solders, so it’s a popular method

for refinishing the older soft-soldered doubles. However, like

most caustic salts, you can’t use it on anything other than

the chromemoly steels normally found on modern firearms.

It won’t color stainless steel or any aluminum alloys.

Because it does such a good job of coating the metal and is

so much less time-consuming than the traditional rust blues,

hot water bluing has become widely accepted as the basic

and most desirable finish for doubles. A traditional rust blue

might take several days to several weeks to complete, but

you can normally complete a hot water blue in about an hour

or so after you polish the metal and prepare it for bluing.

As you would expect, since the hot water bluing process

takes more time than caustic salt bluing, it’s normally more

expensive. Your customers should pay 25 to 50 percent more

for hot water bluing than for caustic salt bluing.

Your customers may occasionally use the terms hot dip and

hot tank bluing. Technically, both caustic salt bluing and hot

water bluing use heated or hot tanks and you dip or suspend

Metal Finishing

workpieces in the tank. Be sure that you explain the differ-

ences in the processes to your customers and understand

exactly what they want. It’s better to spend a few additional

minutes talking with your customer than to spend literally

hours repolishing and rebluing a gun.

In terms of equipment, hot water bluing requires much less

than caustic salts bluing. You can do it efficiently with as l

ittle as two heated tanks, one for a cleaner and one for the

hot water. The heat source for these tanks can be Coleman-

type camp stoves.

The materials for hot water bluing aren’t as hazardous as

those for caustic salts bluing. While you should certainly

wear gloves and protective gear when working with any hot

water blues, the primary danger is from the boiling water in

the bluing tank.

Many gunsmiths who have started their own shops have

initially begun by offering hot water bluing. The fact that it

requires so little equipment makes it an attractive option.

Be aware, however, that because the process is very labor

intensive, you may not have time to do more than two or

three guns per week. (We cover details about the process

and how you do it later.) For now, keep in mind that because

the operation is so involved with carding, applying the bluing

solution, and so forth, there’s a lot of room for operator error.

It’s not as foolproof a process as a caustic salt. It takes time

and practice to become consistently successful with hot

water bluing.

Traditional Rust Bluing

As mentioned earlier, bluing metal on firearms goes back

hundreds of years. Gunsmiths offered guns with blued bar-

rels and other components as early as the 1600s. While the

formulas they used for their bluing compounds were closely

guarded secrets—part of the art and mystery of gunsmithing—

some of the later formulas are now available through such

books as Firearm Bluing and Browning by R. H. Angier.

If you face a situation that requires traditional rust bluing,

Angier’s book is an excellent source of information. In addi-

tion, the book Gunsmith Tips and Projects, by John Bivins,

includes a helpful chapter on custom metal finishes.

14

Metal Finishing 15

Basically, a traditional rust blue actually rusts the surface of

the steel. You control the rusting by the frequency and degree

of carding or wire brushing that you do, as well as the

amount and type of rusting solution applied to the metal.

Rust bluing is a time-consuming and sometimes difficult

process to undertake. Consequently, true traditional rust

blues are often quite expensive. However, on the positive

side, these finishes can be extremely durable and abrasion

resistant. The color obtained can range from black to bluish-

black. Normally, this isn’t a high-gloss finish but rather very

subdued, dulled by the etching action of the bluing formula.

Virtually all rust bluing formulas call for the use of several

corrosive acids to produce the rusting. Most are such that it

will require extended periods, many hours or days, between

coats for satisfactory finishing. This alone would certainly

limit its usefulness. In addition, most of the old formulas are

very sensitive to humidity. If the air has less than 60 percent

humidity, it will be very difficult to get the parts to rust. On

the other hand, if humidity exceeds 90 percent, you may find

that your rust bluing solutions are too aggressive.

If your customer insists that you furnish a traditional rust

blue, it’s best to use one of the currently available commercial

compounds, such as Pilkington’s Classic American Rust

Bluing Solution. With a solution like this, you need not

worry about locating a variety of archaic chemicals, getting

the mixture just right, or dealing with a deadly poison. Just

follow the directions from the manufacturer.

You can use birchwood Casey’s Plum Brown for a quick, rel-

atively easy traditional-type rust blue. Following the bottle

instructions, simply apply the Plum Brown to a barrel heated

with a propane torch. After you obtain a nice even brown

finish, submerge the barrel in a tank of boiling water for 30

to 45 minutes. This procedure will produce the nicest dull

black you could ask for. You could probably convert any of

the fast browning solutions, such as Plum Brown, to a black

by boiling.

Nitre Bluing

Nitre blue is a traditional blue that is recently regaining pop-

ularity. Gunsmiths and some major firearms manufacturers,

such as Winchester during the latter part of the nineteenth

century, used this type of bluing fairly often. It provides a

distinctive and attractive blue color. Occasionally, a knowl-

edgeable customer may ask for this type of metal finishing,

especially on a specific component of a firearm or on acces-

sories for a custom firearm.

You create the color by controlling the heat of the work-

pieces. The salts, commercially available through Brownells,

are composed primarily of potassium nitrate with additional

amounts of sodium nitrate and sodium nitrite. In an unheat-

ed state, these salts are in a dry granular form. When you

apply heat, the salts will liquefy. To get a workpiece to take

on a blue color, you must heat the nitre salts to between 600°

and 650°F. Then, you submerge the polished, clean, dry

parts in the solution. Since the liquefied salts are clear, it’s

easy to observe the changing of color. When you reach the

appropriate color, you remove the workpiece and either quench

it in warm water or allow it to air cool. Once you do this,

rinse the parts in hot water to remove residual nitre salts

that may become attached to the surface of the workpiece.

As you can see, this is a relatively simple and straightforward

process. However, there are limitations on how and where

you can use nitre bluing. You should never use it on parts

that have soft-soldered components. The heat (over 600°F)

and the corrosive nature of the salts will attack the solder.

The finish obtained from nitre bluing is attractive, but not

very durable. We don’t recommend it for firearms that will

receive a lot of handling.

You might consider adding this process to your shop so that

you can properly color some firearm components. The safety

and trigger on Luger pistols, for example, should be a straw

color. You can achieve this with nitre salts by removing the

part from the salts when the part reaches the straw color.

Providing services like this and paying attention to important

details will go a long way toward setting you apart from the

Metal Finishing16

Metal Finishing 17

run-of-the-mill gunsmith. It will also help you attract

customers that know and care about work done carefully

and skillfully.

Nitre bluing requires a welded steel or cast iron container, a

thermometer that will reach up to 900°F, and appropriate

safety gear such as gloves, a face shield, and a heavy-duty

shop apron. As you would expect from working with solutions

at more than 600°F, you must be extremely careful to avoid

splatter and burns.

Because this type of bluing isn’t common, your customers

should expect to pay an additional fee when you color special

parts or components with nitre salts. It’s not something that

every gunsmith will want to do.

Browning

As the name implies, the browning process applies a brown

finish to metal. This is one of the oldest traditional finishes

and predates bluing by perhaps many centuries. Basically,

browning is just controlled rusting.

As mentioned earlier, the book Firearm Bluing and Browning

by R. H. Angier contains many original formulas for browning

used during the nineteenth century and earlier. However,

you should use one of the modern commercially available

compounds such as Birchwood Casey’s Plum Brown. These

newer products are easier to use, safer, and produce more

consistent results.

You’ll find that most of your customers who want this type of

finish are blackpowder shooters. A brown finish is popularly

accepted as more appropriate for traditional muzzle-loading

firearms.

Browning is easy to apply and requires very little equipment,

especially if you use a modern commercial browning such as

Plum Brown. First, you polish and thoroughly clean the metal

to remove all traces of grease and oil. You then heat the metal

with a small propane torch until a drop of water will just siz-

zle on the barrel. Next, apply Plum Brown with swabs in long

even strokes. The greater the number of applications, the

darker and richer the color.

Metal Finishing

Browning is an extremely durable finish, yet one which

requires a minimal amount of equipment. Normally, you

wouldn’t polish a workpiece to a grit higher than 400, if that

high. Polishing any higher is a waste of time since the brown-

ing etches the metal as it colors. Fees for browning average

just a bit below those charged for caustic salt bluing.

Electroless Nickel Plating

Electroless nickel plating is a type of metal finishing that was

developed around the end of World War II. With continuous

refinement and development, it became possible to utilize

this finish on firearms by the late 1960s and early 1970s.

This is a finish that not only some major firearms manufac-

turers can use, but gunsmiths can also successfully apply it

in a small shop with little specialized equipment.

You should add electroless nickel plating to the services

you offer after you establish your shop and get set up with

standard caustic salt bluing and accelerated rust blues. The

reason for this is simply that you use electroless nickel pri-

marily on handguns. In a general repair shop, the majority

of your refinishing work will be on rifles and shotguns. For

the most part, that’s where the money is.

Basically, during the electroless nickel plating process, you

prepare the workpiece and suspend it in the heated plating

solution. This solution, heated to about 195°F, contains a

high concentration of a special nickel alloy. The nickel in the

solution attaches in a uniform and predictable way to the

workpiece. It’s a simple and straightforward process.

Compared to the old electroplating process, electroless nickel

plating has numerous advantages. First, electroless plating is

deposited with complete uniformity over the entire surface of

the workpiece. The old style electroplating would deposit more

nickel on edges; flat areas would not receive as much. The

surface in corners would sometimes be “bridged” by plating

or not plated at all.

Electroless nickel is smoother and tougher than chrome, is

more resistant to peeling and cracking, and has a hardness

of 53–56 on the Rockwell C scale. By any measure, the newer

electroless nickel is far superior to the older electroplating.

18

Metal Finishing 19

Of major importance to you as the applicator is the fact

that this newer form of plating doesn’t require the use of

any poisonous salts solutions. It’s much safer for you to

work with, and regulations allow UPS to ship the materials

that you need for the process.

The primary drawback of electroless plating, and plating in

general, is that you use the process almost always only on

handguns. This limits the market potential. A second draw-

back is that you must use special containers such as a

porcelain tank to hold the plating solutions during the plat-

ing process. While you can use standard porcelain enamel

canning boilers for handguns, larger tanks necessary for long

guns are not readily available and are very expensive when

custom made.

When offered, we usually price electroless nickel plating

services 20–30 percent higher than caustic salt bluing for

the same type of firearm. Fewer shops offer this service, so

prices are typically somewhat higher.

Electroless nickel plating supplies are available from a

number of sources. Most gunsmith shops use the material

available from Brownells.

Parkerizing

Without a doubt, parkerizing is the most misunderstood metal

finishing process you’ll encounter. In the years following

World War II, the parkerized finish found on military surplus

arms was almost universally disliked. Many an old gunsmith

spent hours and hours removing the parkerized finish from

1903A3 Springfields, M1 Carbines, and Colt 1911A1.45s

before rebluing. It was only in the late 1970s and early

1980s that gun owners began to accept and even demand

this type of finish.

The process, sold and promoted by the Parker Chemical

Company, originally consisted of placing the workpieces in

an acid solution with manganese dioxide. The manganese

formed a very porous coating on the workpiece, thus allowing

it to hold oils effectively. The oil provided most of the rust

protection.

It would be too costly and complex for you to set up a parker-

izing system such as that employed years ago by the United

States Army at the Springfield Armory. Such a setup would

require some fairly sophisticated equipment so that you could

accurately monitor the manganese level in your solutions.

The introduction of several modern stove-top parkerizing

solutions, such as those offered by Mount Labs or Palmetto

Arms, helps us to avoid this problem. The solutions come

premixed. You simply prepare the workpiece and suspend it

in the solution at the appropriate temperature for a specific

time period. The primary drawback to these solutions is that

the zinc phosphate in the solution becomes depleted after

doing a limited number of workpieces.

Another factor you should be aware of is that the acid normal-

ly found in these solutions will etch the workpiece. Because

of this, you should never allow the parkerizing solution to

enter the bore of a good rifle or pistol barrel. With a shotgun

it would not be as critical, as you can later easily repolish the

bore and chamber.

Parkerizing services normally cost 20–40 percent more than

bluing because of the greater expense per workpiece for the

chemical solutions.

Once you apply a parkerized finish, you can easily blacken

the finish simply by running the gun through your caustic

salts tank. Countless United States military firearms have

been blued or blackened in this manner.

Baking Lacquer

There’s an increase in the use of nonbluable parts, such as

aluminum alloy trigger guards and receivers. This increased

usage brings about a need for a quick and economical method

to color these components. Baking lacquers have enabled

many shops to provide this service. Basically, you polish,

bead blast, or sandblast the parts and then thoroughly clean

them. You then apply a special paint or lacquer with an air

brush. After the lacquer dries for several hours, you cure the

workpiece in an oven for a specific time and at a specific

temperature.

Metal Finishing20

Metal Finishing 21

At present, I’m aware of only a black and a clear baking

acquer available commercially. Other colors may become

available in the future. For 99 percent of your work, black

is all that you’ll need. With baking lacquer, you can easily

duplicate the anodized finish used by Remington on the 870

and 1100 trigger guards or by Mossburg on the Model 500

shotgun receiver.

If you polish and air brush the parts to about 400 grit, you

can achieve a smooth gloss finish. You can also sand or

bead blast the workpiece surface if you desire a matte finish.

While not as durable as the original anodizing on aluminum,

baking lacquer provides a good wear-resistant finish.

Keep in mind that you can also use this type of finish on the

nonbluable Winchester 94 receiver (those with serial num-

bers above 2,700,000), cast iron shotgun receivers, and so

on. You’ll find its range of potential uses almost unlimited.

Charges for applying a baking lacquer finish are 20–25 percent

less than for caustic salt bluing. If you are bluing a firearm

with some nonbluable components, such as the trigger guard

on a Remington 1100 shotgun, you must give such compo-

nents a baking lacquer finish. In such cases, it’s appropriate

to add an additional charge for refinishing that component.

You might charge $50 to reblue the 1100, plus an additional

$10 to refinish the trigger guard, for a total of $60. (Supplies

necessary to offer a baking lacquer finish are available from

Brownells.)

Flame Coloring

Flame coloring is somewhat like heat bluing since the surface

of the metal becomes colored through the direct application

of intense heat. In most instances, you use an oxyacetylene

welding torch for the heat source. You polish the metal at

least to a 400 grit and then thoroughly clean it with a solvent

such as 1,1,1 trichloroethane.

In flame coloring, you hold the part with pliers or vise grips

and dunk it in a large container of quenching oil, a special

oil used for heat-treating metal. Quenching oil has a very high

flash point and is the only type of oil that you should use for

flame coloring. Don’t use regular motor oil or lubricating oil.

Metal Finishing

Next, you pull the workpiece from the oil, and position the

welding torch with a small clear blue flame near the surface

of the workpiece. Varying the distance from the workpiece

and the length of time that you hold the torch in one area

will cause various colors to appear. With a bit of practice, you

can learn to run color across the surface of the workpiece.

You’ll get a variety of colors ranging from blue to green to

yellow. Gunsmiths experienced with this procedure can do

a good job of duplicating a color case hardened finish. After

you complete the coloring, carefully clean the workpiece and

give it a coat of a clear polyurethane or clear baking lacquer.

Although flame coloring isn’t as durable as color case hard-

ening, it’s a viable alternative for coloring cast iron receivers.

I’ve used this technique many times on older single-barrel

shotgun receivers that were originally color case hardened.

Fees for flame coloring are usually about the same or slightly

less than those charged for caustic salt bluing. Quite a few

fairly high dollar side-by-side and over and under shotguns

imported from Europe have had flame-colored receivers. It’s

not necessarily a low-dollar procedure.

Jeweling

Jeweling is a metal finishing process that we sometimes also

referred to as engine turning or damascening. In jeweling, you

apply a series of swirls or circles to a highly polished surface.

The swirls may overlap, or you may uniformly space them.

The resulting symmetrical patterns reflect light and provide

a pleasing appearance. Although it’s possible to blue a part

after you jewel it, you leave most jeweled parts, such as rifle

bolt bodies or handgun triggers and hammers, “in the white.”

Although the minor surface scratches made to create the

swirls will retain oil for lubrication, the primary use of

jeweling is decorative.

You can create the swirls of jeweling by using a special tool

such as that produced by Tom Menck. You use this tool in

a drill press and it holds a specially sized cratex rod. You

allow the rod, made of a rubber-like material embedded with

a fine abrasive, to turn in the drill press. Then, bring the end

of the spinning rod to bear briefly against the highly polished

22

Metal Finishing 23

workpiece. The abrasive leaves a track in the form of a small

circle or swirl. Next, you move the workpiece to apply another

swirl. Repeat the process until you complete the desired

|pattern.

Jeweling is fairly time-consuming and requires some special-

ized equipment. The charge for jeweling a bolt-action rifle

bolt can range from $20 to $50. It’s well worth offering this

service if you have a drill press in your shop.

Cold Bluing

You find a large variety of commercial cold bluing solutions

currently on the market and available in virtually every gun

shop, sporting goods store, hardware store, and discount

house in the country. Such solutions are sold primarily as

touch-ups to allow the gun owner to easily repair or darken

small worn areas such as those near the muzzle of a pistol

barrel, where holster wear will often remove the original

finish.

Cold blue, which is actually a form of black plating, can do an

adequate job of providing temporary coloring to chromemoly

steels. For the most part, you shouldn’t consider it a substi-

tute for caustic salt bluing or accelerated rust blue on better

grade guns. Cold blue, in most cases, isn’t as durable as other

types of finishes, and the color achieved with cold bluing isn’t

easily matched with the original color of a caustic salt or rust

blue finish.

Over the years, I’ve seen a fairly direct relationship between

how easily a cold blue will color metal and the durability of

the finish. If the cold blue goes on easily, it will normally

come off or wear quickly as well.

I’ve also found that the various brands of cold blues will

react differently with specific metals. Because of this, I usu-

ally keep a half dozen or more different cold blues near my

bench. If one brand won’t properly blue a part, I immediately

try another brand and so on. Very seldom will I find a part I

can’t cold blue.

Metal Finishing

Virtually all cold blues contain some type of acid, usually

selenious acid. Acids can, on occasion, cause a bit of trouble.

If the original finish isn’t especially durable, the acid in the

cold blue may discolor it or remove it altogether. Be very

careful when working with cold blues. There have been

instances when someone, attempting to recolor just a small

area on a barrel, ended up bluing the entire gun.

If you drop a screw or pin in a bottle of cold blue, remove it

immediately. Otherwise, the acid in the cold blue will etch

the screw to the point of ruin.

If you follow the directions from the manufacturer, you’ll

usually do a good job of cold bluing. Remember to have your

workpiece properly prepared so that the cold blue can react

to the base metal. For best results, remove all rust, oil,

grease, dirt, and any original finish.

I’ve had very good results with cold blues sold by Brownells,

Birchwood Casey, and Gun Parts Corporation. My primary

use of cold blue is in retouching the heads of screws and

pins.

Other Metal Finishes

So far you’ve studied the more common types of finishes that

you might someday offer in your shop. There are a number

of other finishes that for a variety of reasons are seldom

ever applied in a small shop. Most often, this is because the

process requires very expensive or complex equipment.

Aluminum Anodizing

Small shops seldom offer Aluminum anodizing, which is a

form of electroplating, at this time. To re-anodize parts as big

as a Mossburg 500 receiver or a Ruger Blackhawk pistol grip,

you must employ a very large and expensive electrical power

unit. Aluminum anodizing is also a fairly involved process,

much more complex than electroless nickel plating. For

example, anodizing is initially colorless. After you apply the

anodizing, you must then color or dye the piece. You can

utilize virtually any color. Years ago, High Standard offered

a small .22 revolver that was available in gold, pink, blue,

and other unusual colors.

24

Metal Finishing 25

Electroless Plating

We briefly discussed Electroplating, or electrolytic plating, in

the discussion of electroless nickel plating. Years ago, electro-

plating was a more commonly offered finish in gunsmith

shops around the country. Now you’ll find this service very

seldom offered. Electroless plating has basically taken the

place of electroplating because (1) it’s a better finish and

(2) the chemical solutions necessary for electrolytic plating

are so hazardous that shipment is terribly expensive. Most

shops simply can’t afford to offer electrolytic plating any

longer.

Color Case-hardening

Color case-hardening is a form of heat treating that not only

imparts a surface hardness to metal but also provides a very

attractive mottled appearance. A nicely done color case hard-

ened receiver will have blues, greens, reds, and other colors in

an attractive random pattern. Color case-hardening was most

often used on cast iron double- and single-barrel shotgun

receivers as well as on some early lever-action and single-shot

rifle receivers.

To duplicate color case-hardening, you must have a very

large and consequently very expensive heat-treating furnace.

After you polish and suitably prepare the workpieces, you

place them in a sealed cast-iron container with a special

type of charcoal. You then place the container in the furnace

and heat it to over 1000°F for a specific length of time. Next,

you remove the container, quickly pull off the cap to the

container, and dump the contents into a special aerated

quenching vat.

As you would imagine, this process requires a lot of knowl-

edge of metals and proper heat-treating. It’s somewhat risky

because the parts may warp if not properly set up with jigs

or braces. There’s little information available in print about

this process, and most folks who do this work have spent

years learning by trial and error.

Teflon

Finally, you’ll have customers ask about various finishes that

utilize Teflon. Teflon is a coating material owned exclusively

by DuPont. To offer true Teflon coating, you must be licensed

by DuPont.

Frankly, I’m not all that impressed with Teflon as a gun coat-

ing. Though a number of outfits have offered it, including some

gun manufacturers, it has some definite drawbacks. Although

Teflon offers some advantages as a slick, self-lubricating fin-

ish, it’s not particularly tough and it scratches easily, which

exposes the base metal causing it to rust. As rust spreads,

the Teflon coating peels away. Also, you must usually apply

Teflon over a phosphate finish because it won’t adhere to

plain steel or to other finishes.

Metal Finishing26

Metal Finishing 27

Self-Check 2

1. What are the major components of caustic bluing salts?

__________________________________________________________________________

2. What will happen if you place an aluminum part in a caustic salts bluing bath?

__________________________________________________________________________

3. What are some advantages of hot water or accelerated rust bluing over caustic salts blu-ing?

__________________________________________________________________________

4. Can you use hot water or accelerated rust blues on stainless steel?

__________________________________________________________________________

5. What is the basic component of most rust blue formulas?

__________________________________________________________________________

6. If the humidity in your shop is less than 60 percent, how will this affect a traditional rustblue?

__________________________________________________________________________

7. What created the color in nitre bluing?

__________________________________________________________________________

8. Which is the more durable finish, a traditional rust blue or nitre bluing?

__________________________________________________________________________

9. At what temperature will nitre blue steel?

__________________________________________________________________________

10. Electroless nickel finishes are most often used on what type of firearms?

__________________________________________________________________________

(Continued)

Metal Finishing28

Self-Check 2

11. What is a primary function of the phosphate coating placed on steel during parkerizing?

__________________________________________________________________________

12. Why shouldn’t you allow parkerizing solutions to enter the bore of a rifle or pistol barrel?

__________________________________________________________________________

13. Why should you use baking lacquer on a Remington 870 trigger guard?

__________________________________________________________________________

14. How should you apply a baking lacquer?

__________________________________________________________________________

15. What type of oil should you use for flame coloring?

__________________________________________________________________________

16. What do you do to protect the finish on a flame colored part?

__________________________________________________________________________

17. What is the primary reason for jeweling a part?

__________________________________________________________________________

18. How can the acid contained in a cold blue cause trouble?

__________________________________________________________________________

19. Why should you clean a part before using a cold blue?

__________________________________________________________________________

20. What type of problem might you encounter in case-hardening a part?

__________________________________________________________________________

Check your answers with those on page 103.

Metal Finishing 29

THE REFINISHING SHOP ANDSAFETY

Offering Refinishing Services

Assume for a moment that after completing the Gunsmith

Program you open up your own shop. You start out small,

either full or part time, with an emphasis on buying and sell-

ing used firearms, but occasionally special ordering a new

firearm. Of course, you’ll be doing some gunsmithing, limited

at first, but expanding as you gain experience and can afford

to add equipment to your shop.

You should consider offering at least some metal finishing

services right from the start. By doing this, you’ll set your

shop apart from other guns sales stores in your area. You

can also use your refinishing skills and equipment to

upgrade some of the used guns you obtain by purchase or

trade. You may be able to double the selling price of some

used guns by doing this. At the beginning, when you have

more time than money, this can be especially important.

Don’t forget that metal finishing encompasses a variety of

different processes—not just rebluing. The procedures may

include

• Jeweling—You can jewel the bolt on an otherwise drab

andordinary .22 single shot and really make it look

sharp.

• Using baking lacquer—Again, this might just be the

thing to make a worn aluminum anodized receiver or

trigger guard look great.

• Flame coloring—Sometimes this is the only way to make

thereceiver of older single-barrel shotguns look decent.

The point is that you shouldn’t put metal finishing on the

back burner. Give at least some type of metal finish the high-

est priority for implementation as soon as you open the doors

of your shop.

Years ago, when I opened my shop, one of the first services I

offered my customers was caustic salt bluing. I did this in

part because no one else in my area offered it. By providing

this service, I immediately attracted attention and got many

folks into my shop. The start-up costs were modest, and I

could make good money quickly on my labor. Since I made my

own tanks and stands, I had to purchase only the chemicals

and burners. It was a great way to get cash flowing into the

shop.

How to Market Your Services

Again, assume that you have made the decision to offer some

metal finishing services such as caustic salt bluing, hot water

rust bluing, jeweling, and baking lacquer finishing. You’ve

gathered the necessary equipment, studied your Gunsmith

lessons and the manufacturer’s instructions, practiced, and

developed the ability to provide these finishes in a competent

and professional manner. Now, how do you let folks know

that you can do these wonderful things?

Begin by visiting every gun club in your area. Contact the

club president or program chairman and offer to give a short

talk (20 to 30 minutes) on metal finishing. Most of the clubs

in your area will probably jump at the chance to have you

over. You’ll be the answer to a program chairperson’s prayer.

Be sure to take as many samples of your work as possible,

so folks can see what you are talking about. Take a few

pieces along that are only partly completed so you can show

the various steps—in polishing, for example. With the ques-

tions the members will ask you and the discussion that

results, that 20 minute talk will probably stretch into well

over an hour. If you make a good presentation, you’ll almost

assuredly walk out of the meeting with jobs lined up.

You should also visit some of the gun stores in your area

that don’t offer gunsmithing or refinishing. Ask to speak to

the manager and explain what services you offer. You may

be allowed to put out your business cards in the shop or

even put up a flyer about your services.

Metal Finishing30

Metal Finishing 31

Some of the very best sources of referrals are the discount

houses in your area. That’s right, discount houses—those

same ones that sell guns even cheaper than you can buy

them. Simply show the managers of the sporting goods

departments that by dealing primarily in used guns and in

offering gunsmithing services, you’re not a threat to their

business. Once you do this, the rest should be easy.

Finally, run a small but regular ad in your local newspaper.

Nothing big or expensive is necessary. A one inch ad stating

that you offer gunsmithing and rebluing services is about all

that you need. The secret to advertising success is to run the

ad regularly for an extended period. If your local paper is

weekly, then figure that you’ll need to run the ad for at least

three months without a break. Sometimes it takes a long

time for readers to notice a particular ad.

In promoting your business, remember that you must be

energetic; let the world know that you’re there! You can’t visit

just one club, speak with one store owner, and take out one

ad and expect everyone to know where you are and what you

do. Only when you have more business than you can handle

can you afford to cut back on your promotional efforts.

Sales Aids

“A picture is worth a thousand words.” In the case of metal

finishing, a sample you can hand to a potential customer

is worth even more. No matter how articulate you are, no

matter how well you can describe something, explaining the

difference between a 320 grit and a 500 grit polish can be

almost impossible. Many of your customers won’t even know

what a grit is, much less the significance of 320 and 500.

There’s a way to make all of this real to your customers and

help you get more business at the same time.

The idea is very simple. Take a number of 4 to 6 inch pieces

of old rifle or shotgun barrels and refinish them in different

ways. Polish one piece to a 240 grit and then blue it. Polish

another to a 300 grit and then blue it. Polish a third piece

400 grit and blue it. Sandblast and blue a fourth piece and

then brown another section, and so on.

When you complete all of these pieces, mount them on an

attractively finished piece of walnut or oak. Now you have

something that you can show customers as you talk about

refinishing their rifles or shotguns. The terms 320 grit, 400

grit, salt blue, hot water blue, and so on will have real mean-

ing. Customers will understand what you’re talking about

and will be able to make an informed decision about the type

of service needed.

Another simple idea that you may consider is keeping a color

photograph album of guns on which you worked. This idea

worked well in my shop. If a customer brought in a really

rough old beater to the shop for rebluing, I would take a

picture of it before and after I did the work. I would put

the before and after photos in my album and then put the

album on the counter for potential customers to browse

through. It worked like a charm. I know for a fact that

those photos brought in quite a few additional jobs.

I would also give “before” photos to customers when they

picked up their completed guns. I always thought there was

a good chance the owners would proudly show off their “new”

old guns. It would mean a lot to me in new business if they

could also show their friends what the gun looked like before

I did my work. Again, it worked like a charm. The cost was

just pennies, but it paid off time after time.

Finally, be sure to always keep at least one rifle or shotgun on

hand so that you can show a potential customer what your

bluing is like. There are lots of folks that do metal finishing,

and let’s face it, some don’t do a very good job. You need to

have a sample of your work on hand so that your potential

customers can see it and have confidence that you’ll do the

metal finishing in a competent, professional manner.

These are just a few of the sales aids and techniques that

you could use. None are very expensive, yet all can go a

long way toward helping to make your metal finishing more

profitable.

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Metal Finishing 33

Potential Problems and How to AvoidThem

Before you begin to examine the potential problems related to

metal finishing, you as a gunsmith need to keep one idea

above all else foremost in your mind. That is, you’re offering

a service to your customers. You’re in business, either part

time or full time, to help them. They’re your reason for being.

Your customers aren’t an inconvenience, an interruption, or

something to be barely tolerated. Remember always that

without them, you won’t have a business or a shop.

Yes, on occasion you’ll encounter a customer who has had

a bad day, someone who’s not very pleasant. You may even

meet that rare person who will try to take advantage of you.

But for goodness sake, try to keep a positive and helpful atti-

tude in regard to your customers. It will make your life more

pleasant, and it will reflect in how your customers treat you.

With that said, let’s look at a few things that you can do rela-

tive to metal finishing that will make it easier to maintain a

positive attitude. Anytime you receive a gun for refinishing or

repair, examine it thoroughly in front of the customer. If

parts are missing or damaged, point that out and make a

note of it on the repair tag or work order. If the gun comes

with accessories such as a sling, scope, case, extra magazine,

and so on, make a note of that as well. This will help to avoid

confusion later.

When you take on a refinishing job, be sure to give the cus-

tomer an estimate of the total cost if you don’t have a flat fee

or charge. No one likes to be surprised by a big bill. It’s a

good idea to give your customers an estimate that is a bit

high. Then, when you tally up the charges, they’ll be under

the estimate. Customers like to have pleasant surprises like

that. Of course, you should make a note of your estimated

charges on the repair tag.

After the customer has left and before you take the gun apart

to do any refinishing, check to make sure that it actually

works. If you find a problem or a broken part, stop right

there. Contact the customer immediately and explain what

you found. Get the customer’s approval for additional repairs

before you do them. The owner may not want the repair done

or may not want to invest any more money in that firearm.

Metal Finishing

After you complete your work and before you notify your cus-

tomer, test-fire the gun in a safe and appropriate manner.

Under normal conditions, you should always test-fire any

gun on which you work. Not only is this for your own safety

and liability, but it also enables you to be sure that when

you return the gun to its owner, it works properly. You may

even consider test-firing the gun in the presence of the owner

when he or she comes to pick it up. It takes a bit of extra

time, but by doing so you can avoid having guns returned to

your shop because they don’t fire properly.

If for any reason a gun can’t be test-fired, mark the repair

tag “not safe to fire.” Tell the customer why and ask him or

her to sign the repair tag. If anything later goes wrong with

the gun, you’ll have a record of warning the customer.

One situation that you can count on facing is having a cus-

tomer ask you to refinish a gun that was in a fire. You’ll see

guns that show signs of minimal damage, just a bit of discol-

oration from smoke and water, to those that are blackened,

twisted lumps of scrap. Your customers will want you to

repair the guns. Before taking any fire-damaged guns, you

must understand that in some situations, the extreme heat

that these guns were exposed to could alter the strength of

the steel. It could make the gun totally unsafe.

How can you tell if a gun was exposed to too much heat? In

one sense you can never really know. However, there’s one

rule of thumb: If you see that the stock has been burned or

charred, it was undoubtedly exposed to too much heat. Don’t

work on it, period!

If the stock is in good shape, then you can feel quite comfort-

able refinishing both the metal and the wood. If the stock

isn’t charred, you can assume that the temperature did not

exceed around 200°F.

Expect the unexpected when working with fire-damaged

guns. The smoke and water present in a house fire can cre-

ate acids and chemical solutions that we can only describe

as a witch’s brew. No one knows what’s in it or how it will

affect the steel or wood. Smoke-damaged barrels and

receivers have often given gunsmiths a great deal of trouble

in getting a good finish. The surface of the metal seems to

endup chemically altered so that it wouldn’t take a finish in

a normal manner.

34

Metal Finishing 35

The best advice is to be extremely cautious in refinishing any

fire-damaged guns.

Safety

As with any type of work involving chemicals, there’s always

a potential for accidents that could result in severe injury.

You can avoid accidents by being careful as you work and

by paying close attention to the manufacturer’s directions

and a few simple safety rules. In this section, you’ll study

safety issues pertaining to metal finishing. In one sense, this

is the most important part of this text—it could save your

life! Become completely familiar with the information that is

provided. If you don’t understand something, keep going over

it until you do.

Personal Safety Equipment andProcedures

Years ago, a gunsmith commented, “If you’re using any

chemical that you would not eat or drink, you had better

wear gloves when you handle it.” I have thought of this

often over the years, and the more I think about it, the

more I believe he was 100 percent correct.

Whenever you work with hazardous chemicals, always be

extremely careful. When using a caustic bluing salt, for

example, you should always wear a full face shield. Suitable

heat resistant gloves are a must. Wear a neoprene apron to

protect your clothing (and your skin) from the boiling salts

(Figure 2). Wear rubber boots, because caustic salts will eat

through leather. Regular shoes and boots are almost worthless

from a safety standpoint. You should also wear a long-sleeved

shirt to protect your arms. Heavy-duty, long cotton or denim

trousers are also a necessity. Finally, wear something to

protect your head, such as a navy-style watch cap.

This basic outfit would be suitable for most bluing and plat-

ing. It may seem to be extreme, but remember that you are

trying to prepare for the unexpected. A surge of plain boiling

water forced out of a rifle or shotgun barrel can cause injury

just as easily as sulfuric acid.

Always keep a well stocked first-aid kit in your shop. The

kit should include the standard equipment for normal cuts

and abrasions. In addition, if you’re doing caustic salt bluing,

you’ll need to add a bottle of vinegar, which effectively neutral-

izes salts that might splatter on your skin.

You’ll also need a fire extinguisher in your bluing and refin-

ishing area. Since you’ll often use natural or LP gas for heat-

ing solutions, the possibility of a fire does exist. A general

purpose fire extinguisher is cheap fire insurance.

When you work with any chemical, always try to have a

source of running water close at hand. This will allow you

to thoroughly rinse off as much as possible in the event of

an accidental spill.

Always take time to read the manufacturer’s instructions

and especially the safety warnings prior to use. Keep these

instructions in a file that someone else can easily find if you

become incapacitated due to an accident. Also keep in this

file all appropriate copies of Material Safety Data Sheets

(MSDS). We’ll discuss them in the next section.

Keep the telephone number of your local hospital or emergency

service posted near your phone. When an accident happens,

you don’t have the time to thumb through a telephone

directory.

Metal Finishing36

FIGURE 2—Essential equip-ment for caustic salt bluingincludes a first-aid kit, a fullface shield, a neoprene shopapron, rubber boots, protectivegloves, and a container of vine-gar. NEVER use caustic saltswithout having and using theseitems.

Metal Finishing 37

Finally, keep everyone out of your work area. A bluing room

with a salts tank going full steam at 292°F is no place for

children or shop visitors. You’ll face enough risks yourself

without having to watch out for other people at the same

time.

Material Safety Data Sheets

A few years ago, Congress passed some laws that consumers

should know about. Basically, these laws state that anyone

who uses a product that contains a hazardous material has a

right to know about it and about the potential harmful effects.

Thus was born the MSDS, or Material Safety Data Sheet.

Every manufacturer is required to have these sheets and to

make them available to the user. The MSDS won’t tell you

everything that a product contains, but it will list all the

hazardous components, and it explains how to dispose of

the product properly. Most importantly, it will tell you or

your doctor what action should be taken if the hazardous

components make external contact or are taken internally.

It’s therefore of greatest importance that you have the MSDS

of any product you use and keep these in an appropriate file.

Keep it where your spouse, coworker, or doctor can find it.

When you need it, you usually need it in a hurry.

Any reputable manufacturer will have MSDS’s and will make

them available immediately. If you’re thinking about using

a material that’s potentially hazardous—bluing salts, for

example—and the seller won’t or can’t furnish an MSDS,

then consider a different product or brand.

Metal Finishing38

Self-Check 3

1. If, as part of your business, you buy and sell guns, why should you consider doing somemetal finishing?

__________________________________________________________________________

2. If you offer metal refinishing services, where’s the best place to spread the word aboutyour shop?

__________________________________________________________________________

3. Why are sales aids helpful?

__________________________________________________________________________

4. Why should you give a customer an estimate of charges?

__________________________________________________________________________

5. Should you test-fire guns before you return them to their owners?

__________________________________________________________________________

6. What is a good rule of thumb regarding fire-damaged guns?

__________________________________________________________________________

7. What item normally found in your kitchen can you use to neutralize caustic bluing saltstht might have splattered on your skin?

__________________________________________________________________________

8. What is a Material Safety Data Sheet and why is it important?

__________________________________________________________________________

9. What safety equipment should you wear when performing caustic salts bluing?

__________________________________________________________________________

Check your answers with those on page 104.

Metal Finishing 39

METAL PREPARATION

Introduction

So far you’ve studied the history of finishes, the various types

of finishes available, marketing your finishing service, and

various safety issues. You’re now ready to begin your study of

the metal finishing process. To refinish a metal surface, you

must first prepare it to receive the finish. This includes dis-

assembling the firearm, cleaning the components, removing

the old finish, and preparing the metal surface for the new

finish.

Disassembly

You’ll occasionally have a customer who will bring you just

one item for refinishing, such as a “bag gun” (explained later)

or a rifle bolt for you to jewel. In most cases, however, you’ll

start with a completely assembled firearm that you’ll have to

disassemble to the degree necessary to do the job required. If,

for example, a customer brings you a Marlin 336 lever-action

rifle to be reblued, that will mean complete disassembly of the

rifle. The only two components that should still be together

on the 336 are the barrel and the receiver.

Whenever you do caustic salt, hot water, or nitre bluing;

parkerizing; or plating, you must completely strip the gun.

If you fail to do this, you’ll definitely ruin some parts, such

as springs, which are especially sensitive to heat.

Over the years, I’ve seen quite a few guns that were blued

without being fully stripped. Once an old Marlin lever-action

rifle in .44-40 was brought into my shop by a fellow who

complained it wasn’t feeding properly. It was pretty clear why:

someone gave the gun a hot caustic salts blue without taking

it apart! The only concession to proper procedure was that

the gunsmith removed the buttstock and forearm before it

went into the salts tank, but that was all. It was the worst

situation that I ever saw. I have also seen quite a few trigger

assemblies and rifle bolts that were left intact during the

bluing process. In every case, there was major damage to

some parts.

Metal Finishing

If you’re not sure how to take a particular gun apart, don’t

just hop in with a screwdriver and start taking out screws

left and right. First, get some instructions on the proper way

to disassemble that specific gun. These instructions are

included in the NRA Firearms Assembly and Disassembly

Guides, Vol. III and IV, which we include as part of this

program.

You’ll also want a copy of the six-volume set, Firearms

Assembly and Disassembly, by J. B. Wood. The Remington

Field Service Manual is also very helpful, as well as Bob

Brownell’s Encyclopedia of Modern Firearms.

As you become more involved in gun work, you’ll see the

absolute necessity of having a good firearms library. There’s

no way that you can know how to disassemble the hundreds

of different firearms that you’ll eventually service. Don’t

waste your time trying to learn them all. Get the books that

will help you and have them on hand when you need them.

We mentioned earlier a bag gun, which is something that

most gunsmiths have seen from time to time. A customer will

decide to do a bit of work on his or her own. The customer

will somehow get the gun apart and then realize that he or

she doesn’t know how to get all those little parts back togeth-

er. In a panic, the customer dumps everything that looks like

a gun part into a paper bag and brings it in for you to fix.

Don’t ever question these people too closely as to how the

gun came apart or why. It’s just amazing how many guns

were taken apart by their kids, their brother-in-law, or their

buddy at work. In 15 to 20 years of gunsmithing, I’ve never

had the owner of a single bag gun acknowledge that he or

she took the gun apart.

Assuming that you have a manual of sorts that will guide

you through disassembly, there are a couple of other items

that you need before you start. You need a clean place to

work. Make sure your workbench is clean and free of all

other gun parts. You don’t want parts from different guns

mixed together (Figure 3).

Get at least two separate containers or shallow boxes to hold

the parts as you strip the gun. Be sure to take pieces of

masking tape and write the make, model, and serial number

of the gun on each piece of tape and apply one piece to each

box.

40

Metal Finishing 41

As you disassemble the gun, put those parts that you’ll blue

or refinish into one box and all other parts into the other box.

Make sure that the boxes have solid bottoms. You don’t want

to lose any small screws, pins, or springs.

If you have a component that’s fairly complex with lots of

smaller parts, such as a Mossburg 500 trigger assembly,

make a rough sketch that shows the relationship of some

of the critical parts. Even a very basic drawing will help

when it comes time to reassemble the gun.

Make sure that you have the proper tools on hand for disas-

sembly. These include hollow-ground gunsmith screwdrivers,

a set of high quality pin punches, a set of roll pin punches, a

nylon and brass drift punch, a one-inch nylon/brass hammer,

and any other required specialized firearm-specific tools.

Keep in mind that you can easily damage a firearm during

the disassembly process if you don’t use the proper tools.

If you have a gun for which you can’t find disassembly

information, proceed with extreme care. In fact, you should

probably consider not taking on a gun such as this until you

have a good bit of experience under your belt. In the begin-

ning, stick with the more common guns on which you can

get disassembly information.

FIGURE 3—A messy bench likethis is no place to disassembleor reassemble a gun. If yourbench looks like this, clean itup. You must have a clean,uncluttered spot in which towork.

Metal Finishing

When it comes time to reassemble the firearm, it will go a lot

easier if you don’t permit a great deal of time to pass since

you first took it apart. That may sound silly, but you would

be surprised at the number of gunsmiths who for all sorts of

reasons will let months pass before a gun is finished to the

point that he or she can reassemble it. Plan your work, start

the job, stick with it, and finish it in a timely manner. Even

if you work as a gunsmith part time, you can arrange your

work so that at most it should not be over a week to 10 days

since you initially disassembled the gun. You’ll remember

more and it will go back together more easily.

During reassembly, again, work on a clean, uncluttered

bench. Lay out a clean, soft cloth for a bench mat. Place

the parts on the cloth in a row or two so that you can see

them all as you are reassembling the gun. This will help

you avoid losing small parts, and just seeing some parts

will often jog your memory as to how they go together.

Work slowly and don’t get into a rush. Take your time so

that you don’t scratch the gun or mar the finish during

reassembly. Be careful!

Cleaning

After disassembling the gun, you should thoroughly clean the

parts that you’ll refinish to remove dirt, grease, grime, loose

rust, etc. If left on the parts, this “crud” would hamper the

removal of the old or original finish. At the very least, having

dirty parts would cause you to spend more time removing the

old finish than is necessary. You’ll soon come to appreciate

how important your time is. You have only so many hours in

which to work, so you must work quickly and efficiently.

You can use any number of different solvents to aid in clean-

ing. One of the most commonly used is 1,1,1 trichloroethane.

It’s effective both when used in a bath or when applied with a

soft cloth as a swab. (It’s likely that the use of trichloroethane

will eventually become restricted due to concerns about envi-

ronmental contamination.)

Another excellent cleaner is Brownells’ d’Solve. It’s nonhazard-

ous, nonflammable, biodegradable, and yet very effective. It’s

sold as aconcentrate that you dilute with water. One gallon

42

Metal Finishing 43

of d’Solve will make up to five gallons of cleaner. When I use

it, I either use it straight or dilute it no more than two gallons

of water to one gallonof d’Solve.

You may see other gunsmiths using gasoline, kerosene, or

Coleman fuel. Don’t use these fuels. Never use a flammable

material as a cleaner. It’s a safety hazard of the first order.

Far too many shops burned to the ground or were severely

damaged because the gunsmiths attempted to use fuel as a

cleaner. It’s not worth the risk.

If you can afford one of the small bench-top cleaning tanks,

that’s great. It will be very handy and save you lots of time.

If money is a bit short, you can do quite well with a couple

of metal bread pans, a few old one-inch paintbrushes, and

toothbrushes.

After you have removed any surface crud, you’ll be in a much

better position to see just what the metal surface is really

like. At this point, you can proceed with the next step,

removing the old finish.

Removing Old Finishes

Now that you’ve disassembled the gun, separated the parts

you’ll refinish from those you won’t, and thoroughly cleaned

all parts, you need to remove any rust or original finish

remaining on the parts you’ll refinish. For a well-done, pro-

fessional finish, it’s essential that you completely remove any

surface coating on the metal along with all scratches, rust

pits, or other imperfections. In this section, you’ll study two

methods of removing the finish: removing it with chemicals

and removing it by abrasion.

Chemical Methods of Removing Finishes

Whether you are bluing, plating, or using any of the other

numerous finishes currently available, it’s best to use chemi-

cals on the initial step in metal refinishing. There are two

reasons for this. First and foremost, by utilizing a chemical

stripper, you can drastically cut the amount of metal that

you remove during the polishing or buffing of a typical gun.

Almost any time you put a gun part on a buffing wheel, you’ll

remove some base metal. It might be a very slight amount,

but it doesn’t take much metal removal around the lettering

stamped on a gun barrel to make the lettering look faint or

washed out. As a gunsmith, you should be especially careful

when refinishing that you always keep all lettering or num-

bers sharp and distinct. This alone will go a long way toward

establishing a reputation of competency and skill.

Second, chemicals allow you to quickly see the condition

of the metal surface. Often rust or old bluing may hide

imperfections that will require special effort to remove.

On normal blued chromemoly steels, you can remove the

finish by placing the cleaned part in a vat or tank of com-

mercially available blue and rust remover, such as that

sold by Brownells. The Brownell’s product comes as a liquid

concentrate that you can dilute as much as 1 : 3 with clean

water. When diluted only 1 : 1, it’s very effective, even with

heavy rust. Brownell’s Blue and Rust Remover is basically a

mild acid solution.

If you want to make up your own blue and rust remover,

be careful! Some acids are so strong and powerful that they

will quickly etch or eat into the steel. It doesn’t take much

imagination to see how this could easily ruin the bore and

chamber of a fine rifle barrel. If you stick with one of the

known commercial products, such as Brownell’s or

Birchwood Casey’s Blue and Rust Remover, you need not

worry about some home brew getting out of hand and dam-

aging a fine gun. Just follow the manufacturer’s directions

and you should encounter few, if any, problems.

From time to time a customer will ask you to refinish a

firearm that has been plated. Typically, this will be a hand-

gun and normally the plating is nickel. While it’s possible to

grind, sand, or polish off the plating, it’s much easier and

faster to use a reverse electroplating process. The most effec-

tive plating removal involves using a chemical stripper along

with an electrical current.

One of the most effective stripping solutions for plating is

Super-Strip, available from Brownells. Super-Strip is a pow-

der that mixes with water to form the stripping solution. You

attach the part you want to strip with a wire to the positive

terminal of a six-volt, 90–100 amp battery and then place it

Metal Finishing44

Metal Finishing 45

in the Super-Strip solution to become the anode. Attach a

sheet of steel or iron to the negative terminal with a wire to

become the cathode. The cathode is also suspended in the

Super-Strip.

The movement of the electrical current from the positive to

the negative pole in the solution activates the Super-Strip.

The plating will break down and pull away from the work-

piece, or anode, and then it will settle in the bottom of the

Super-Strip container. Actual stripping time can take from

five minutes to two hours depending on the size of the work-

piece and the nature of the original plating. Without a doubt,

this is one of the most convenient and easy-to-use electro-

chemical stripping solutions available.

Finish Removal by Abrasion

There are a number of different abrasion methods that you

can useto remove an old finish. Included here are the more

commonly used procedures you could easily employ in your

own shop.

Sand and bead blasting. With the increased popularity of

matte, or dull nonreflective metal finishes, the use of sand

and/or glass bead blasting has increased dramatically.

Coupled with more economical equipment, it’s now common

for even small shops to offer sand or bead blasting services.

In this process, very fine silica sand or special glass beads

are forced under high air pressure through a hand piece, or

“gun,” and directed against the surface of the workpiece. In

most setups, you can control the degree of abrasion by raising

or lowering the air pressure or by increasing or decreasing

the distance from the hand piece to the workpiece. Normally,

the higher the pressure and the closer you hold the hand

piece to the workpiece, the rougher the finish.

You can also control the texture of the finish by varying the

grit, or size, of the sand or glass beads. The smaller the grit

of the sand or the size of the beads, the finer the resulting

finish in most cases.

The major difference between sand and bead blasting

involves the nature of the blasting materials. Silica sand,

even when extremely fine, is composed of millions of jagged

rocks. These tiny rocks will tear away and gouge the surface

that you direct them against. Of course, with extremely fine

silica sand, the scratches are superfine and present a frosted

appearance on steel.

Glass beads, on the other hand, are very tiny round balls,

often no more than 0.0005 inch in diameter. When the

glass beads strike a steel part, they peen the surface and

leave millions of small, overlapping rounded depressions.

Normally, glass beads won’t remove metal as aggressively

as sandblasting.

It’s especially important that you always perform glass bead-

ing in a sealed cabinet. The glass beads will shatter in use,

creating a fine dust of glass particles. Breathing this dust

can cause severe injury to your lungs. If you use glass beads,

you must use a sealed blasting cabinet that can contain

all dust. While it’s best to use a sealed cabinet when sand-

blasting, you can do it outside if you wear a suitable dust

respirator.

A one horsepower compressor combined with a small

portable sandblasting outfit can be economical for a small

shop. By offering a matte finish for hunting rifles and shot-

guns, and even some handguns, this equipment can quickly

pay for itself. Blasting the tops of receivers on shotguns such

as the Remington 870 and 1100 and the Ithaca 37 gives the

shotgun a nice, nonreflective area on the top of the receiver.

This contrasts nicely with the smooth, more highly polished

receiver sides.

Sandblasting is especially useful on a severely pitted firearm.

Sometimes handguns become so heavily rusted that it’s

virtually impossible to polish out all the pits. By giving the

guns a rather coarse sandblast finish, you can effectively

camouflage the pitting. If done properly, the guns appear

to have a black parkerized finish.

When bead or sandblasting, you should always clean the

parts thoroughly before blasting. This is especially important

for glass beading, as the peening action of the beads may

literally beat contaminants into the surface of the steel.

Metal Finishing46

Metal Finishing 47

Use tape, molding clay, bore plugs, and so on to protect any

areas that you don’t want blasted. For example, when sand-

blasting a revolver, use a heavy masking tape to cover the

front and rear of the cylinder. Protect both ends of the barrel

by inserting tight-fitting dowels into the bore. Fill the openings

for the hammer and trigger with modeling clay to prevent any

abrasive from entering the frame. On a bolt-action rifle, mask

off the receiver ways and preserve the smooth surface where

the bolt moves back and forth. Again, you should protect the

bore at the muzzle and the opening to the chamber in the

receiver.

After sand or bead blasting, clean the workpiece thoroughly

and immediately apply a coating of protective oil, unless

you plan to do your bluing or other metal finishing within

a matter of minutes. Otherwise, rusting may begin. Even

though this rusting is on a microscopic level that you can’t

see, it can cause severe problems later when you perform

caustic salt bluing or plating.

Draw filing. Draw filing is a useful technique for severely

pitted guns. While it’s possible to buff the surface of the

metal down enough to remove the rust pits, draw filing can

accomplish the same task in a more uniform and controlled

manner. It’s also helpful as a method of preparing octagonal

barrels or flat-sided receivers, such as those found on

Winchester lever-action rifles. Draw filing will enable you

to maintain an absolutely true, flat surface.

In draw filing, you can use virtually any metal file. It’s best to

use a single-cut file, such as a lathe file or a file designed

specifically for draw filing (Brownell’s Draw File, for example).

The file that you use should be in good condition with sharp,

well-formed teeth. Before using a file, clean it to remove any

preservative oil, and apply file chalk to prevent metal chips

from clogging the teeth. If not removed, these chips will cause

deep scratches on the surface being draw filed (Figure 4).

Position the file so that the long axis of the file is at right

angles to the workpiece, with one hand on each end of the

file. Be sure to position the file so it will cut as you pull it

toward you. You’ll cut only when you draw the file toward

you. You must never push the file backwards on the work-

piece, as this will dull the file teeth. With a very slight down-

ward pressure on the file, draw it towards you. You’ll imme-

diately notice how it cuts a smooth, flat surface. It won’t

remove a lot of metal with a single stroke, but the metal it

does remove will be very uniform. Continue your draw filing

until you remove all pits (Figure 5).

Metal Finishing48

FIGURE 4—Using file chalkenhances the effectivenessand extends the useful life ofyour files. You should also usea file card or brush frequentlyto remove metal chips from the file teeth.

FIGURE 5—Place even pres-sure upon both endsof the draw file as you pull it acrossthe workpiecetoward yourbody. Never push the draw file backwards, as this will dull the file teeth.

Metal Finishing 49

If you’re working on a round surface, such as a rifle barrel,

you’ll create a series of very narrow flats that should overlap

all the way around the barrel. Again, you’ll continue to draw

file until you remove all the pits or imperfections.

Once you remove the pits, you should wrap the file with

abrasive cloth or paper and polish out the marks or scratch-

es left by the draw filing (Figure 6).

Warning: When polishing or buffing, never remove metal

from any part that will alter the headspace. On a rifle bolt,

for example, don’t polish the rear of the locking lugs. Even

the removal of a small amount of metal, as little as 0.002

inch, can create an excessive headspace condition, which

could make the firearm unsafe to use. Don’t remove metal

from locking lugs.

Hand polishing. While most gunsmith shops make exten-

sive use of mechanical buffers and belt sanders, you can do

very fine work by simple hand polishing. We can make a

strong case that hand polishing allows the gunsmith to have

greater control over the removal of metal from the workpiece.

In hand polishing, there is less danger of rounding sharp

corners, washing or dishing out screw and pin holes, or oblit-

erating markings or lettering. Some of the finest custom guns

produced in the world have been totally polished by hand.

Keep in mind that you should first chemically strip the work-

piece. If the surface is heavily pitted, you should then draw

file it until you remove all pits. The workpiece is then ready

to hand polish.

FIGURE 6—After you completedraw filing, wrap the draw filewith abrasive and use it as abacker for even, smooth handpolishing.

Metal Finishing50

It’s best to polish with aluminum oxide cloth-backed abrasive

strips or sheets in grits ranging from 120 up to 500. You do

not want to use regular hardware store sandpaper designed

for wood. In most cases, such sandpapers are too coarse, or

the grit sizes aren’t uniform enough for the detailed work

that metal finishing requires.

Your actual polishing technique will depend upon the shape

of the workpiece. Suppose you have a flat-sided receiver such

as that found on a Winchester 94 or a Marlin 336 to polish.

With any required stripping or draw filing completed, begin

by securing the barrel in a padded vise with unobstructed

access to the receiver. Position the receiver so that one side

is level and facing up. Depending upon the condition of the

surface, select the appropriate grit of aluminum oxide to

begin polishing. The grit selected should leave scratches finer

than what’s already present on the surface. With time and

experience, you’ll soon be able to make a judgment about

this quickly and accurately. If you choose a grit that is too

coarse, you’ll just spend time needlessly polishing. If the grit

chosen is too fine, you’ll have difficulty removing scratches

from prior polishing or draw filing.

Assuming that you begin with a 220 grit abrasive, place the

abrasive strip or sheet around a hard flat surface such as a

file. This will ensure that the flat side of the receiver remains

flat and true with no ripples or high or low spots. Move the

abrasive in one direction initially, back and forth along the

length of the receiver. When you’ve removed all previous

scratches and the surface has a uniform appearance, you

can move to the next higher grit.

With this next grit, again backed by a file or sanding block

made of steel or wood, polish in a direction 90° (degrees) to

the one in which you previously polished. By doing this,

you’ll quickly remove the sanding marks or scratches from

the previous grit. Continue to follow this sequence of alter-

nating the polishing direction as you advance to finer grits.

By the way, you normally want to have your final polish

running the length of the receiver for the most professional

appearance. A 400 grit hand polish is about as high as you

need to go for most guns, but you can go higher. In fact, with

just hand polishing and a lot of time and elbow grease, you

can polish metal to the point that it looks chrome plated.

Metal Finishing 51

Now, suppose you must hand polish a round

surface such as a barrel. Again, finish any

required stripping and draw filing and secure

the workpiece in a padded vise. Position the

barrel so that you have unrestricted access.

Select the appropriate grit, and using a strip

of abrasive cloth placed across the barrel,

use a shoe-shine motion to work the abrasive

back and forth and up and down the full

length of the barrel. Continue this around

the entire surface of the barrel, removing all

previous sanding marks. Once you achieve a

uniform surface finish, you can move to the

next higher grit (Figure 7).

As with the flat receiver, you’ll do the next

polishing step at 90° to the previous polish-

ing. This will mean moving back and forth

along the length of the barrel. When doing

this, you should use a backer such as a file

or flat piece of hardwood for the abrasive.

This will ensure that no ripples develop from

the shoe-shine polishing step (Figure 8).

Advance to successively finer grits until you

reach the surface finish required. The last polish should

always be lengthwise along the barrel.

FIGURE 7—On round barrels, you work a strip ofabrasive cloth in a shoe-shine motion back and forth,up and down the length of the barrel.

FIGURE 8—Alternate the shoe-shine technique by polishingthe length of the barrel with astrip of abrasive backed by awooden sanding block.

Be sure to check your work carefully before moving to a

higher grit. If you miss a small scratch, it can be difficult to

remove with the higher grits. It’s better to eradicate the

scratches with a coarser grit because it’s faster and easier.

Many gunsmiths use a drop or two of kerosene on the metal

when using the aluminum oxide abrasive cloth. The kerosene

keeps metal particles from clogging the abrasive cloth. These

particles tend to keep the abrasive cloth from cutting aggres-

sively and efficiently.

Belt polishing. The use of motor-driven polishing belts is

very common in the major firearms manufacturing plants

and is gradually coming into greater use in smaller shops.

A small one-inch belt sander or a combination six-inch belt

sander and sanding disk of the type sold by Sears can be

very handy in your shop. Not only will you use the belts for

metal finishing, but you’ll also need them for fitting recoil

pads to rifle and shotgun stocks.

A device that you may find helpful is the Scott Murray sand-

ing drum. It’s a wheel, 8 inches in diameter and 2 inches

wide, which fits on a Baldor buffer. The unique thing about

the Scott Murray drum is that the metal flange or center is

covered by a rubber drum that expands as the wheel turns.

This expansion is limited by the sanding belt that’s placed

around the surface of the wheel. You use it just like a regular

sanding belt or muslin or felt wheel. The primary advantage

of the Scott Murray drum is that it enables you to quickly

and easily change belts and grits.

By the way, never turn on the buffer with a Scott Murray drum

installed if the drum doesn’t have a sanding belt mounted on

it. If you do, the drum will self-destruct! The centrifugal force

of the spinning wheel will pull the rubber off the steel flange.

The wheel will become ruined in a matter of seconds.

A wide, 6 inch belt sander is just ideal for quickly truing and

initially polishing the flats on a receiver like that found on a

Remington 870. Just recently I had a very poorly polished

frame for an old Colt 1911.45 auto. By removing all parts

from the frame, I was able to simply hold the flat sides of the

frame against the belt. In a matter of minutes, I restored all

the nice sharp corners and eliminated the washed-out areas

around the pin holes.

Metal Finishing52

Metal Finishing 53

While I use belts primarily for flat components, I do use the

Scott Murray drum to polish round barrels. When I do this,

I use a Clymer Barrel Spinner, available from Clymer

Manufacturing, 1645 W. Hamlin Road,

Rochester Mills, MI 48309, or from

Brownells. This device holds the barrel

between two nylon or wood centers that are

set in bearings. Thus, when the barrel con-

tacts the wheel, the rotation of the wheel

also tends to rotate the barrel. By varying

the angle of the barrel against the wheel, I

can control the speed of the barrel rotation

and the aggressiveness or cutting action of

the belt. The least amount of cutting occurs

with the barrel held at 90° to the surface of

the wheel; the most, when the barrel is

held straight up and down (Figure 9).

When polishing with a belt, begin by holding

your workpiece, a barrel for example, at

about 45° from vertical to the center of the

wheel. After polishing the length of the bar-

rel, put the next finer grit belt in place and

reverse the angle to 45° in the other direc-

tion. Always cross your previous polishing

marks just as you did for hand polishing.

Sanding belts are available in grits ranging

from 60 grit (extremely coarse) to 600 grit.

With the variety of grits available, you can

do a very nice job of metal preparation with belts alone.

When a belt becomes fairly worn, don’t throw it away. You

can probably used that worn 220 grit belt as a good 320 grit

belt. About the only time I ever throw a belt away is when it

finally breaks or tears.

Preparing the MetalNext to hand polishing, using machine-driven felt or muslin

wheels is the most common method of preparing workpieces

for refinishing. You’ll find a buffer of some type in virtually

every shop. Although some folks use the term polish and

some use the term buff, the terms mean the same thing and

we use them interchangeably.

FIGURE 9—Using a Clymer Barrel Spinner and aScott Murray Sanding Drum makes polishing a barrel very fast and easy. This Baldor buffer comesequipped with hoods and an exhaust system to control the dust that occurs during polishing. If your buffer doesn’t have an effective dust-controlsystem, you must wear a dust respirator.

By far, the best way to go with buffing equipment is to dig

down in your wallet and purchase a Baldor buffer. Baldor

has been producing buffing equipment for years and is the

standard with which we compare other buffers. The motors

are sealed to keep out polishing dust and grit and will seem-

ingly last forever. They’re not cheap by any means, but they

are first-rate, quality pieces of equipment. Brownells offers a

variety of Baldor buffers in their catalog.

When you are looking at buffing equipment, you must con-

sider size and speed. A one horsepower motor with a speed

of 1725 rpm (revolutions per minute) will provide plenty of

power. However, the wheel speed won’t be so great and may

create problems in getting polish to adhere.

Another point to keep in mind when looking at buffing equip-

ment is the length of the shaft or arbor, which should be as

long as possible. The Baldor’s shafts are double ended so

that you can mount a buffing wheel on each side of the

motor. You want these wheels as far apart as possible.

Nothing is worse than hitting the 240 grit wheel with your

barrel when you are working on the 320 grit wheel. A separa-

tion of about 30 inches is good; any less will cause problems

from time to time.

If the money just isn’t available for a new or used Baldor,

then you should look at the possibility of utilizing a salvaged

electric motor to power a buffer arbor and pillow block set. A

pillow block set consists of drive shafts that are set in pillow

blocks with bearings. You just hook up your motor with a

belt and you’re in business. It’s cheaper than a Baldor and

a lot of gunsmiths have started out with these homemade

buffing outfits. Pillow blocks and arbors are available in

most large hardware stores, and of course, from Brownells.

If you make up one of these outfits, try to keep your motor as

far from the polishing wheels as possible. Many of the motors

used in setups like this aren’t sealed, and the polishing grit

can be sucked inside the motor housing, destroying the

motor bearings.

Now that you have your buffer set up, you need to put some

wheels on it. There are three basic types: felt, stitched muslin

(a form of cotton), and loose muslin. Felt wheels, which come

in various sizes and hardnesses, are the most rigid. Because

Metal Finishing54

Metal Finishing 55

of this, these wheels are more aggressive and will remove

metal faster than a stitched muslin wheel loaded with some

grit polish. The rigidity of the felt also permits polishing over

screw and pinholes without so much danger of washing out

or deforming the sharp, crisp edges of the holes.

A disadvantage of felt wheels is that they can cost many

times as much as a similar size muslin wheel. They’re not

cheap. In addition, when using a felt wheel you must always

approach the face of the wheel directly with your workpiece.

If you come in at an angle, the edge of the wheel can quickly

cut a groove in your workpiece. Felt wheels are definitely not

for the beginner.

The next most rigid is the stitched muslin wheel. The word

stitched comes from the fact that multiple layers of cotton

cloth are sewn together to provide strength and rigidity.

Stitched muslin has some of the advantages of felt, yet it is

much less costly. Since it’s softer than felt, you must exer-

cise greater care when working near screw and pin holes.

The last type of wheel you’ll encounter is the loose muslin

wheel. This is like the stitched muslin except the layers

of muslin or cotton cloth aren’t sewn together for the full

diameter of the wheel. Usually there’s just a row or two of

stitching around the arbor holes to keep the layers of cloth

together. A loose wheel, because if its greater flexibility, is

less aggressive. You use it for a final pass in a given grit to

enhance the surface finish.

You should probably begin by working with only stitched

muslin wheels. As you gain experience and buffing skill, you

can add additional wheels—first loose muslin, then perhaps

a few felt wheels. Use the largest diameter wheels that you

can. I prefer 10 inch wheels. The large diameter gives you

plenty of surface area on the wheel. Also, when you’re work-

ing with muslin wheels, you should stack them on your

arbor. Since most stitched wheels are only 3/8 inch wide,

they’re much too narrow for most polishing. You should use

a minimum of three of these 11/8 inch wheels side by side to

form one wheel 1 inches wide.

Once you have a wheel set up on your arbor, take a magic

marker and, on the side of this wheel, write the grit of the

polish that you intend to use. Also, draw an arrow showing

the direction of rotation. Never, never use the wheel with any

other grit polish or run it in the opposite direction of your

arrow.

Before applying your polish, make sure that the face of the

wheel is trued, or leveled. You can also expect that the wheel

will be a bit out of round. To level the face and true the wheel,

use a Wheel Rake, available from Brownells, or an old worn-

out wood rasp. This is a messy job that creates a good deal

of cotton or felt lint. Keep a vacuum handy to suck up as

much of this as possible. Don’t try to short cut this step as

you can’t do a good buffing job if you don’t set up the wheels

properly. Also, if the wheels aren’t trued, it will make apply-

ing polish very difficult.

There are lots of different polishes on the market, and most

will do a good job. In selecting polish, stay away from any

that contain iron oxide as a cutting agent. You’ll encounter

major problems if you try to blue a part that has been buffed

with a polish containing iron oxide. Knife makers, who don’t

blue their blades, primarily use this type of polish.

Also stay away from grease-based polishes, which will also

cause problems during the bluing or plating process.

I’ve used Brownell’s Polish-O-Ray polish for almost 15 years

and am very pleased with it. I don’t think you could go wrong

by using it too.

When using buffing wheels, keep plenty of polish on the

face of the wheel. Remember, the muslin or flat wheel doesn’t

polish or cut metal—the polish does the cutting. If you wear

through your polish, stop and apply more. Failure to do so

means that you’re wasting a lot of time and are wearing out

your wheels.

If given proper care, your wheels will last a long, long time.

I just measured the diameter of some stitched muslin

wheels that I’ve had for over 15 years. My 10 inch wheels

are between 91/2 and 93/4 inches in diameter. With proper

care, your wheels can last just as long.

Metal Finishing56

Metal Finishing 57

When not using your wheels, keep them in large plastic bags.

This will ensure that dust and grit from other wheels used

nearby won’t settle on them.

With your wheels set up and ready to go, you can begin pol-

ishing. Start by using the correct grit necessary to remove

pits and surface imperfections. If you start with too fine a

grit, you’ll spend lots of extra time on the buffing wheel. On

a typical gun, you can begin with a 240 grit polish and work

up to a 400 grit polish.

Position your workpiece so that it’s at approximately 45° to

the perpendicular face of the wheel. After you complete pol-

ishing with this grit, advance to the next higher grit and alter

the position of your workpiece so that you’re at 90° to the

angle of the first pass. By doing this, you’ll polish across

the polish or grit marks left by the previous polishing pass

(Figure 10).

FIGURE 10—When using a buffer,position the workpiece approxi-mately 45 degrees to the verticalface of the polishing wheel for theinitial polishing. Notice the gun-smith holds the barrel with barehands to better monitor the heatingof the workpiece. If the workpiecegets too hot to handle, you’re doingsomething wrong.

If you don’t alter the position of the workpiece and polish

with the grit marks of the previous step, you’ll simply deepen

rather than remove them. If there’s a secret to effective pol-

ishing, this is it (Figure 11).

On your last polishing pass, polish the

length of the workpiece. On a barrel, for

example, position it so that it’s perpendicu-

lar with the face of the polishing wheel.

Your final polish on all parts should be

parallel to the axis or center of the bore

(Figure 12).

Metal Finishing58

FIGURE 11—When you usethe next higher polishinggrit, position the barrel sothat you polish across theprevious grit marks.

FIGURE 12—Do the final polishingwith the barrel held verticallyagainst the polishing wheel. Notethe use of a full face shield for eyeand face protection.

Metal Finishing 59

Some folks suggest that you wear gloves when you polish.

This isn’t a good idea. If you polish without gloves, you can

monitor the temperature of the workpiece. If it becomes too

hot to hold with your bare hands, then you need to stop for

a bit and change your technique. You should polish with a

light touch, not a heavy hand! If you push your workpiece

into the wheel so hard that the friction causes the piece to

heat up—stop—you’re polishing wrong!

Let the polishing grit do the work. You need only a minimal

amount of pressure to hold the workpiece against the face of

the wheel. If you use enough pressure to cause the face of

the wheel to flare out, that’s too much.

Note: Never alter, remove, or obliterate all or any part of a

firearm’s serial number. To do so is a violation of federal law.

Always keep this in mind when working on a receiver near

the serial number.

Metal Finishing60

Self-Check 4

1. When rebluing a gun, just how far should you go with the disassembly?

__________________________________________________________________________

2. Why should you have books about guns in your shop?

__________________________________________________________________________

3. Why should you not use gasoline for cleaning parts?

__________________________________________________________________________

4. What is the advantage of using a chemical stripper to remove the old finish?

__________________________________________________________________________

5. Which is more aggressive, sand or bead blasting?

__________________________________________________________________________

6. What are the three types of commonly used buffing wheels?

__________________________________________________________________________

7. Which is more aggressive, a hard wheel or a soft wheel?

__________________________________________________________________________

8. When you set up a wheel on your buffer, what should you mark on it?

__________________________________________________________________________

9. Why should you always polish across your previous grit or polish marks?

__________________________________________________________________________

10. If your workpiece gets so hot during buffing that you can’t hold it in your bare hands,what’s wrong?

__________________________________________________________________________

Check your answers with those on page 105.

Metal Finishing 61

REFINISHING EQUIPMENT ANDPROCEDURES, PART 1In this section, we’ll look briefly at specific types of metal

finishes with emphasis upon the materials and equipment

required and the basic procedures for each. We’ll also

describe how to use each piece of equipment.

Caustic Salt BluingIt’s certainly possible to perform caustic salt bluing with less

equipment than that listed below. However, including this

equipment as part of your setup will enable you to provide

caustic salt bluing efficiently with a minimal amount of diffi-

culty. Some equipment you may already have, some you can

construct yourself, and some items you may have to purchase.

The list is a guide only, but it represents what I personally

would use in my own shop (Figure 13).

Materials and Equipment Required

Bluing salts. Depending upon the brand of salts you use,

the specific amount required to charge your bluing tank will

depend upon the size of your tank and the salts manufactur-

er’s instructions. Normally, the requirement is approximately

10 pounds of salts for each gallon of water.

FIGURE 13—This is an idealsetup for caustic salt bluing.The tank on the far left is forthe cleaner; the next tank isfor the cold water rinse. Notethe hose leading into the rinsetank as well as the dischargehose located near the floordrain. The next tank, againstthe far wall, is the salts tank.The last tank, on the far right,is for the boil-out.

Cleaner. You use a cleaner to degrease or clean the work-

pieces before you place them into the salts tank. Brownell’s

Dicro-Clean 909 is a mild industrial detergent that won’t etch

the surface of the workpiece as will so many other stronger

cleaners.

Black iron tanks. You’ll need a minimum of four tanks,

one for the cleaner, one for the cold water rinse, one for the

bluing salts, and one for the boil-out. Although it’s possible

to blue with fewer tanks, it makes the process awkward.

Tanks that are 6″ � 6″ � 40″ are a standard size. It’s difficult

to find burners large enough to efficiently heat tanks larger

than this standard size. Also, a 6″ � 6″ � 40″ tank will

require only about 35 pounds of bluing salts to charge it.

Larger tanks can require so much of the salts that they

become incredibly expensive to set up.

The formula for determining tank capacity is as follows.

Width″(Height – 2)″Length

231= Number of Gallons

Notice in this formula that you subtract 2 inches from the

height of the tank, because you’ll always leave a couple inch-

es of “freeboard” between the top of the tank and the level of

the salts solution to prevent spills. Always reduce the tank

height in your calculations by this amount.

To determine the capacity of a standard tank (6″ � 6″ � 40″)proceed as follows.

�6″(6

2

–

3

2

1

)″40� = �

6″2

4

3

″1

40� = �

9

2

6

3

0

1� = 4.2 gallons

Now assume that a tank slightly larger is used—say,

10″ � 8″ � 48″. The capacity of this tank is as follows:

�10″(

2

8

3

–

1

2)″48� = �

10

2

″63

″1

48� = �

2

2

8

3

8

1

0� = 12.5 gallons

From these calculations, you can see that it would take three

times as much water and therefore three times as much

salts to charge the larger tank. The standard size, which is

adequate, is much more economical.

Metal Finishing62

Metal Finishing 63

While you can use stainless steel tanks for the cleaner, the

cold water rinse, and the boil-out, the salts tank must be

made of either black iron or mild steel. Use of stainless steel

for the salts tank can lead to problems because the stainless

steel oxidizes. Small particles of stainless steel will get into

the salts bath and eventually attach themselves to the work-

pieces, resulting in tiny silver flecks or spots on your blued

guns.

If you make your own tanks, use 18 gauge mild steel and

make sure that the ends are welded with mild steel welding

rod. Don’t braze the corners. The copper in the brazing will

ruin your salts.

Burners. You’ll need three burners: one for the salts tank,

one for the cleaner, and one for the boil-out. It’s important

that you use an appropriate size burner

that provides adequate heat. If it’s too

small, it will take far too long to get your

salts solution up to the proper operating

temperature. Use a burner with at least

42,000 Btu (British thermal units) for the

salts burner. Also, make sure your burners

run the length of your tanks so that your

solutions heat evenly (Figure 14).

Tank stands. You’ll need some method of

supporting your tanks. The stands should

be extremely rigid and stable. Use only mild

steel or stainless steel for the stands. Don’t

use aluminum. The salts will eat away the

aluminum and the tanks will collapse.

Use stands that will enable you to set up

your tanks so that you never have to reach or stretch across

a heated tank. Brownells offers a tank stand that can be

adapted to virtually any conceivable arrangement or tank

layout. You’ll need one stand for each tank, or a minimum

of four stands.

FIGURE 14—There are two shut-off valves on thegas line leading to the burner, one near the end of the burner and the other where the flexible coupling hose joins the main gas line. Always have a minimum of two shut-off valves.

Thermometers. You’ll need at least two thermometers,

one for the salts tank and one for the cleaner. Don’t use a

thermometer that has an aluminum body as this will quickly

dissolve in the salts solution. It’s important that you have a

good, accurate thermometer for your salts tank. The success

of your bluing depends upon being able to accurately moni-

tor the temperature of your salts solution (Figure 15).

Position your thermometer as near the center of your salts

tank as possible. For the most accurate readings, position it

midway along the length of the tank so that the stem of the

thermometer is at least 1 inch from the bottom of the tank

and 1 inch from the sides.

Parts baskets. You’ll need at least two baskets to hold the

small parts, screws, pins, and so on that require bluing. If

you make up your baskets, use black iron or mild steel

screen wire or expanded metal. Do not use aluminum

(Figures 16 and 17).

Metal Finishing64

FIGURE 15—Shown areboth a standard bluingthermometer and a wall-mounted bluing thermome-ter properly positioned inan empty salts tank. Inboth cases, the quills areat least 1 inch from theside of the tank and theend of the quills are atleast 1 inch from the bot-tom of the tank. Both arelocated at approximatelythe midpoint of the length-of the tank.

Metal Finishing 65

Black iron wire. A roll of wire of approximately 18 gauge is

essential for constructing handles for the parts baskets that

hold barreled actions and other small parts. Again, don’t use

aluminum wire or steel wire that has a copper coating (such

as welding rod). Either of these materials will dissolve in the

salts tank and ruin your salts bath.

Stainless-steel dipper.You use a dipper for

adding salts or water to your bath. Make

sure that it’s made entirely of stainless

steel and has a handle at least 12 inches

long (Figure 18).

FIGURE 16—Place large parts in baskets with open-ing as large as possible to permit the best possiblemovement of the bluing salts solution. Note theuseof black iron wire for handles.

FIGURE 17—Blue the small parts in baskets madeof black iron screen wire or expanded metal such asthe one shown here. The openings are small enoughto prevent loss of very small screws and pins

FIGURE 18—Add water to a vigorouslyboiling salts tank carefully. Use a stain-less-steel dipper to spread additionalwater over the surface of the full lengthof the tank. Take care not to splatterthe hot salts bath.

Metal Finishing

Rinse tank brush. Use a soft, natural fiber bristle brush in

the cold water rinse tank to rub down the workpieces as they

come from the cleaner tank. This helps to remove all traces

of cleaner before you place the workpieces in the salts tank.

1,1,1 trichloroethane. Always wipe down your parts with

trichloroethane before you put them into the cleaner tank.

Also, run a patch soaked with trichloroethane through the

bore. This removes most of the oil, grease, or polish residue

on the parts and enables the solution in the cleaning tank

to be that much more effective.

Remember: Your workpieces can never be too clean. The

cleaner, the better.

Full face shield. You have only two eyes and it’s just

plain foolish not to protect them. Always wear a full face

shield when working around a caustic salts bluing system

(Figure 19).

Protective rubber gloves. Industrial-grade rubber gloves

are a must. Forget about the ones you can buy at the grocery

store for washing dishes; they just won’t stand up to the

heat and the salts. Temp-Tec gloves, sold by Brownells, not

only resist chemicals used in bluing and plating, but they’re

insulated to withstand high temperatures as well.

66

FIGURE 19—Here, the gunsmith adds salts to thetank during setup.Noticehis full safety gear includ-ing face shield, cap, long-sleeved shirt, gloves, neo-prene shop apron, heavytrousers, and rubber gloves

Metal Finishing 67

Neoprene shop or lab apron. It’s essential that you wear a

heavy-duty apron to protect yourself from the splashes and

splatters that will occur. A neoprene apron is the only type

that will provide real protection.

First-aid kit and vinegar.Always have a first-aid kit handy.

Also keep a bottle of regular vinegar to neutralize any salts

that might splash onto you. It’s better to smell like a salad

than to be burned by bluing salts!

Fire extinguishers. Since you’re working with open-flame

burners, it only makes sense to have a good fire extinguisher

handy. In almost 20 years, I’ve never needed one, though I’ve

always had one handy in my shop. On the other hand, I do

know of some bad shop fires that could have been controlled

if the gunsmith had a fire extinguisher available (Figure 20).

Rubber work boots. When you are bluing, the work area

will be wet and messy. In addition, salts will quickly eat

through regular leather shoes or boots. Rubber boots are

the only way to go for both safety and comfort.

Water-displacing oil and tank. After you blue the work-

pieces and then put them through the boil-out tank, you

place them in a solution of water-displacing oil. This will

drive out any moisture in the pores of the metal and provide

a protective oil coating. I normally let my workpieces sit in

the water-displacing tank for 6 to 12 hours before I remove

them for reassembly. This also allows time for the bluing to

set up or cure (Figure 21).

FIGURE 20—No matterhow bigor small, simpleor elaborate,every bluing room should contain the two items shown: a large, sturdy bench with several shelves for storing supplies and a fire extinguishermounted in an easily accessiblelocation.

You can use virtually any type of container for the water-

displacing oil. I now use a stainless-steel tank, but I have

made a tank by gluing end caps on a piece of 10 inch PVC

pipe and then splitting it on a band saw.

Be sure that you have some way of draining off the water

that will collect in the bottom of your oil tank. Also, make

sure that your parts are suspended and not allowed to rest

on the bottom of the tank where water might collect. If they

do, you’ll see rusting of your workpiece in the oil tank!

Finally, never, never heat your water-displacing oil. It’s not

required, it doesn’t help in anyway, and to do so creates an

extreme fire hazard.

Salts stirring tool. You can either purchase or make a tool

to stir your salts. It should look a bit like a flat-bottomed

shovel or paddle so that it can scrape salts from the bottom

of the tank. Drill a few inch holes in it so the solution can

flow through the face of the paddle and won’t push out the

end of the tank. A width of about 4 inches is fine. A good

long, sturdy steel handle of about 25 inches or so is about

ideal (Figure 22).

Metal Finishing68

FIGURE 21—Locate thewater-displacing oil tank onthe workbench. Notice thetight-fitting lid proppedagainst the back of the tank to protect the oil from contamination when it’s not in use.

Metal Finishing 69

Instructions from the bluing salts supplier.It’s just incredible

how often people will ignore or will fail to obtain instructions

from the supplier of their bluing salts. The suppliers made

the salts, and they know more about their product than

anyone else. Get these instructions and read them carefully.

Never assume that you can use all salts in the same manner.

If you use Brand X salts, follow exactly the procedures

recommended by the seller of Brand X.

Caustic Salt Bluing Procedure

Before you begin to study the actual bluing procedure, you

need to look briefly at setting up your bluing equipment.

First of all, your bluing setup must be in an area where the

steam and fumes won’t damage anything. You should have a

separate room or a small building where you can do your

bluing. Don’t attempt to do your bluing in the same room

where you have your tools or guns. You’ll soon have extensive

rust damage to these valuable items if you do so (Figure 23).

FIGURE 22—Use a paddlemade of steel to frequentlystir the salts solution. Thishelps to avoid hot spotsand areas of uneven tem-perature. Make sure thepaddle contacts the bot-tom of the tank while stir-ring. Don’t make the mis-take of just stirring the topof the solution.

Make sure that you have a good exhaust

system that draws the steam and fumes

from the salts tank and away from the

operator. The exhaust fan shouldn’t have

aluminum blades, as the salt fumes would

soon cause it to disintegrate (Figure 24).

Attach your tank stands securely to the floor

so there’s no danger of them tipping over.

The same goes for your burners; connect

them securely to the stands. I position my

burners, which use natural gas, so that they

are about 21/2 to 3 inches below the tanks.

When I turn on the burners, the flames will

just begin to spread out on the bottom of the

tanks.

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FIGURE 23—Diagrammedhere is a flowchart of thecaustic salt bluing process.

FIGURE 24—An exhaust fan located above the salts tankexpels the heat, fumes, and steam generated by the saltssolution. Notice the wall-mounted bluing thermometerabove the salts tank.

Metal Finishing71

It’s a good idea to have your local gas service company help

you with setting up your burners. They can make sure that

you have enough pressure and that your system is safe.

Don’t forget to install a main shutoff for your gas lines.

With the stands up and the gas system installed, you’re just

about ready to do some bluing. Before you set your tanks

in place, clean them thoroughly. Wipe them down with

trichloroethane. Remove all traces of any oil or grease.

Put the tanks in position and fill your cleaner tank to within

about inches from the top. Following the manufacturer’s

instructions, add the cleaner that you have chosen. Don’t

turn the heat on at this time.

Now, fill up the cold water rinse tank and the boil-out tank.

Again, fill them to within an inch or so of the top of the tank.

Don’t turn on the burner for the boil-out tank.

You should now set up your salts tank. Read the instructions

from the salts supplier and follow their directions to the

letter. Don’t get creative! Normally, you place approximately

50 percent of the amount of salts that you’ll need in the

tank and then add water. Stir in the salts until they dissolve.

Carefully add more water, bringing the level up to within

about 3 inches of the top of the tank. Now, add another 25

percent of the total salts required. Again, stir in the salts

(Figure 25).

FIGURE 25—Never guess about the quantity of saltsused. Always weigh outtheappropriate amount as recom-mended by the salts supplier.

You can turn on the heat at this point and make sure to

position your thermometer correctly. As you stir your solu-

tion, you’ll note that the temperature will go up to a certain

point and then stop, at which time the solution boils. If the

boiling temperature is below the salts supplier’s recommended

operating temperature, then you must carefully add additional

salts. Adding salts will raise the supersaturation level of the

salts solution, allowing the temperature and the boiling point

to go up.

Gradually work your way up to the point at which you have

a vigorous, rolling boil at the appropriate temperature. The

salts I use, Brownell’s Oxynate No. 7, operate best at

between 292° and 295°F. At this point, the surface of my

tank looks like a storm at sea! I have a vigorous boil with

lots of agitation.

Remember, water by itself boils at 212°F and will not get any

hotter. Adding salts to the water raises the boiling point of

the solution. Also, the higher the temperature, the more salts

that can dissolve in the water. With the No. 7 salts, the opti-

mum amount of salts is in the solution when the water boils

at 292°F. The solution is supersaturated. When allowed to

cool, the salts will go out of the solution and settle at the

bottom of the tank (Figure 26).

If you see the solution getting too hot, you can reduce the

temperature by simply adding water. Don’t attempt to control

the temperature by cutting back on the gas burner.

From time to time, some people encounter water problems.

If there’s copper in your water, it can literally kill your salts

bath. If you have alkaline water, or water with a high iron

content, you should use distilled water, at least for your

salts tank.

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FIGURE 26—This is the way a salts bathshould look. Bownell’s Oxynate No. 7 saltsshould have a vigorous, aggressive boilbetween 292 and 295 °F for best results.

Metal Finishing 73

With your salts tank up to temperature, you can now turn

on the burners under your cleaner and your boil-out tank.

Make sure that you have a thermometer in the cleaner and

that you run it at the supplier’s recommended temperature.

When all your tanks are up to the appropriate operating

temperature, it’s almost time to start bluing. First, take a

scrap piece of old rifle shotgun barrel that you already pol-

ished a bit, clean it with trichloroethane, and run it through

the bluing system. First, run it through the cleaner tank,

next the cold water rinse where you’ll scrub it down, then the

salts tank. Leave it in for 15 minutes or so, then pull it out

and go back to the rinse tank. Carefully examine this test

piece. If you mixed all the solutions properly and you followed

the directions of your supplier, it should be blued perfectly.

If not, something is wrong! It’s better for the error to show

up on the test piece than with that shotgun you spent hours

polishing! Always run your test piece through your solutions

first. It can save you some unpleasant surprises and many

hours of extra work.

Once the test piece gives your setup a clean bill of health,

you can begin work. Blue your barreled actions first. After

you finish those parts, you can then run the parts baskets

through the bluing system. This will help to prevent scratches

or nicks from barrels or receivers hitting the parts baskets.

Again, the sequence of steps in the caustic salt bluing

process is as follows.

1. The cleaner tank

2. The cold water rinse tank

3. The salts tank

4. The cold water rinse tank for inspection to see that all is

well

5. The boil-out tank for 15 to 20 minutes to neutralize any

salts still on the workpiece

6. The water displacing oil tank

Normally a gun will blue in a well-maintained bath in 30

minutes or less. Some mild steel components will blue

almost instantly. Some heat-treated parts may require

longer periods in the salts tank and may necessitate opera-

tion at a higher temperature, up to 315°F. You’ll occasionally

encounter pieces that require a bit of experimentation to get

them to color.

If you ever find that your workpieces develop a coating of

red smut when you take them from the salts tank and place

them in the cold water rinse, that’s a good indication that

your salts aren’t operating with the proper amount of boil at

the correct temperature. Normally, the tank doesn’t have

enough agitation; that is, the boil is too mild.

If the workpieces develop a green color or coating in the salts

tank, that usually means that the temperature is too low.

Finally, if your salts solution turns red, you have major trou-

ble! That’s usually a sign that your bath is burned out or dead.

This is usually caused by excessive heat or contamination.

Given proper care, a salts bath can last for years. Watch

what you put in it, monitor your temperature constantly,

and keep the tanks covered when not in use. If you do these

things, you should get good, consistent results from your

caustic salts setup (Figure 27).

Metal Finishing74

FIGURE 27—Here’s thepayoff for careful workand attention to detail—a beautifullyblued Winchester 1906 .22 rifle.

Metal Finishing 75

Hot Water or Accelerated Rust Bluing

Materials and Equipment Required

Black iron or stainless steel tanks. Ideally, you should

have three tanks: one for the cleaner, one for the cold water

rinse, and one for boiling water. These can be either stainless

steel or black iron. Stainless steel, while more expensive, is

preferable because it resists rusting. Tank specifications

should be the same as those used with caustic salts.

Bluing solutions. At the present time, there are two com-

monly used solutions for hot water bluing: Brownell’s

Dicropan IM and the Herter’s Belgian Blue. Although both

do an excellent job, I prefer the Dicropan IM because it’s a

bit easier to use and considerably less expensive. Both are

available from Brownells.

Cleaner. As with the caustic salts bluing, I use and strongly

recommend Brownell’s Dicro-Clean 909. This mild detergent

won’t etch or damage the workpiece.

Burners for the heated tanks. You’ll need burners to heat

two tanks. While pipe burners are ideal, you can use some-

thing as simple as a double-burner Coleman camp stove. The

heat requirements aren’t that extreme. At most, you must

have sufficient heat to boil water in one of the tanks.

Tank stands. Three stands are required unless you use a

couple of camp stoves. In that case, you could easily set all

of your tanks on a large table.

Swabs for applying the bluing. For swabs, I use sections

of pantyhose that I cut out and pack with cotton balls. The

swabs are usually about 2 inches or so in diameter. I like to

have about a dozen of these swabs made up and ready for

use.

A shallow dish to hold the bluing solution.Always pour

enough bluing so that you have plenty to soak your swabs.

Don’t put used bluing back in the bottle with the unused

portion. Doing so will cause contamination.

Steel wool. Use #1 steel wool that you have cleaned of all oil

and preservatives. You can use trichloroethane as the cleaner.

You should unfold the steel wool and rinse it repeatedly to

remove all traces of oil. After this, allow it to dry. Prepare at

least four rolls of steel wool when hot water bluing (Figure 28).

Paper towels. Cover your workbench with paper towels and

periodically change them during the bluing process. This

helps to keep the work area clean.

Rubber gloves.As with caustic salt bluing, I prefer to use the

Temp Tec gloves sold by Brownells.

Water-displacing oil and tank. After completion of bluing,

suspend the parts in water-displacing oil.

Wood plugs for the workpiece. Ideally, you shouldn’t

touch the workpiece during bluing. If it’s a doubled-barreled

shotgun, you can place a tight-fitting wooden handle in the

muzzle of one barrel and in the chamber of the other. This

will permit water to flow out of the barrels, yet give you han-

dles to hold on to.

Black iron wire. Use black iron wire to construct handles

or holders for the workpiece. An 18 gauge wire is appropriate

for this purpose.

1,1,1 trichloroethane. You use trichloroethane for pre-

cleaning the workpiece. As with caustic saltbluing, the

parts can’t be too clean (Figure 29).

Thermometer. Use a thermometer to monitor the tempera-

ture of the solution in the cleaning tank.

Metal Finishing76

FIGURE 28—Essentials for hot water bluing include swabsmade of nylon pantyhose andcotton balls, a shallow dish forthe bluing solution, steel wool,and Brownell’s Dicropan IM.

Metal Finishing 77

Procedure for Hot Water Bluing

Begin by setting up your tanks. Fill the cleaner and boiling

water tanks to within 1 to 11/2 inches of the edge of the

tank. Add your cleaner according to the manufacturer’s

instructions, and turn on the burners for both heated

tanks. Monitor the temperature in the cleaning tank so

that it doesn’t become too hot (Figure 30).

FIGURE 29—Here, the gunsmithprecleans the soft-soldered shotgun barrels with Brownell’s1,1,1 trichloroethane on a softcotton cloth to remove oil, polish residue, and fingerprints.

FIGURE 30—Diagrammed here isa flowchart ofthe hot water blu-ingprocess.

Metal Finishing

When your tanks reach the correct operating temperature,

place your workpiece in the cleaner tank for the appropriate

length of time. Then, you should transfer it to the cold water

rinse for scrubbing to remove any residue from the cleaning

solution (Figures 31 and 32).

After rinsing, quickly transfer the workpiece to the boiling

water tank. Allow it to remain in the tank for 5 minutes. Pull

the workpiece from the tank and shake off any excess water.

The heated workpiece will dry almost immediately. Holding

the workpiece with one hand, card or rub down the surface

with a pad of clean, dry, degreased steel wool. Remove all

surface discoloration or oxidization that developed in the

boiling water tank. Do this as quickly as possible so that the

workpiece won’t cool. The chemical reaction between the blu-

ing and the workpiece will accelerate if the workpiece is hot.

It’s important that you do this first carding step thoroughly.

If you leave imperfections on the surface of the workpiece,

they’ll show up through the bluing (Figure 33).

78

FIGURE 31—Here, the gunsmith removes the shotgunbarrels from the hot cleaner tank. Note that the bar-rels have both wooden handlesas well as hangerscomposed of steel rods and black iron wire.

FIGURE 32—Use a soft, natural bristle brush to scrubdown the shotgun barrels in the flowing cold waterrinse tank. This removes all traces of the hot cleaningsolution.

Metal Finishing 79

After you complete the carding, apply the bluing solution with

one of the swabs you already prepared. Have the swabs satu-

rated, but not to the point that you get runs on the workpiece.

Make long, continuous strokes with the swab as you apply

the solution. Be sure to thoroughly cover the workpiece. Use

about one minute for the application process (Figure 34).

FIGURE 33—Place the barrels inthe boilingwater tank for 5 min-utes. The steel rod hangers holdthe barrels above the bottom ofthe tank.

FIGURE 34—After youremovethe barrels from the boilingwater tank, quickly card themwith clean, dry degreased steelwool to removeall surface rustanddiscoloration.

Return the workpiece to the boiling water tank and again

allow it to remain for 5 minutes. Remove it and shake off the

excess water. As soon as it dries, take a new

clean pad of steel wool and card the surface.

Again make sure that you remove all surface

streaks, runs, or other imperfections. Work

as quickly as possible (Figure 35).

After carding, apply another coat of bluing

solution with a new swab. Again, don’t allow

runs or streaks to develop. Try not to have

noticeable overlaps. Make your application

strokes long and even over the entire surface.

Return the workpiece to the boiling water

tank for five minutes. Follow this sequence

of steps as many times as necessary until

you get the color and finish desired. In most

cases, between 6 and 12 coats of bluing will

usually give a satisfactory finish. On rare

occasions, a barrel or receiver will require

more.

Following the last application of bluing,

return the workpiece to the boiling tank for

five minutes. After removing it, place it in the water-displac-

ing oil tank. This completes the bluing process. When using

a hot water blue, speed is of the essence. The faster you work

carding and applying the bluing, the better off you are. Don’t

allow the workpiece to cool down (Figure 36).

Most folks who run into problems have failed to properly

degrease their workpieces or their steel wool. It doesn’t take

much grease or oil either on the workpiece or in the boiling

water tank to ruin the bluing.

Metal Finishing80

FIGURE 35—You apply Dicropan IM with a speciallyprepared swab. You then return the barrels to theboiling water.

Metal Finishing 81

The procedure outlined here is basically what is required for

hot water bluing. However, you must carefully read and fol-

low the instructions supplied with both Brownell’s Dicropan

IM and Herter’s Belgian Blue (Figure 37).

FIGURE 36—The barrels receiveseveral coats of Dircropan IM.After you remove them from theboiling water tank, you cardthem with new pads of clean,dry, degreased steel wool.

FIGURE 37—The job is complete. Here’s a beautifully blued set of soft-solderedbarrels.

Metal Finishing82

Self-Check 5

1. What type of tank should you use for the bluing salts?

__________________________________________________________________________

2. How do you determine the capacity of a tank in gallons?

__________________________________________________________________________

3. Can you use aluminum tank stands for caustic salt bluing?

__________________________________________________________________________

4. Where should you locate the thermometer in the salts tank?

__________________________________________________________________________

5. What should you do to raise the temperature at which the salts solution boils?

__________________________________________________________________________

6. When you use a hot water bluing solution, it’s important to apply the bluing solutionwhile the workpiece is hot. Why?

__________________________________________________________________________

7. What causes most problems with hot water bluing?

__________________________________________________________________________

8. What is the term for rubbing down the steel surface with steel wool during the hotwaterbluing process?

__________________________________________________________________________

Check your answers with those on page 106.

Metal Finishing 83

REFINISHING EQUIPMENT ANDPROCEDURES, PART 2

Traditional Rust Bluing

Materials and Equipment Required

Rust bluing solution. As mentioned earlier, there are liter-

ally 1001 rust bluing formulas and compounds. If you wish

to mix your own, refer to R. H. Angier’s book, Firearm Bluing

and Browning, for formula suggestions. Because there are so

many different ways of mixing the compound, comments

given here will by necessity be very general.

Damp box. If you’re going to do authentic traditional rust

bluing, you should build a damp box. This will allow you to

have absolute control over temperature and humidity. You’ll

have a very difficult time doing traditional rust bluing if you’re

not able to control these critical variables. You’ll find infor-

mation on the construction and equipping of a first-class

damp box in the Wolfe Publishing Company book,

Gunsmithing Tips and Projects.

Cleaner/degreaser. Since you are rusting the surface of

your workpieces, it’s absolutely essential that you remove

all traces of grease or oil. An ideal cleaner for this is 1,1,1

trichloroethane. Clean your parts carefully; then clean them

again. Any trace of oil will cause the finish to be blemished.

Gloves. Always wear gloves when working with rust blues,

and never touch the surface of your workpiece with your

bare hands. It’s critical that the surface of the workpiece

not become contaminated in any way if you are to achieve a

uniform finish.

Carding equipment. Depending upon the formula and

specific technique you employ, you’ll need to utilize some

type of carding equipment. This could range from steel wool

to a motor-powered wire wheel. In either case, make sure

that the carding material is clean, dry, and void of any oil.

Procedure for Traditional Rust Bluing

Depending upon the method and formula used, the specific

steps in the traditional rust bluing procedure can vary.

Normally, you begin by cleaning the workpiece and then

applying a coat of the rust blue solution. Next, you place

the workpiece in the damp box for a specified time, after

which you remove and card it. Apply a second coat of bluing

solution, and again return it to the damp box. Repeat this

sequence of steps any number of times over a period that

could range from a few days to several weeks.

When rust bluing, keep in mind that the very nature of

the process entails placing a fine gun in the worst possible

environment—a damp, humid cabinet. There are parts that

you want to rust, but there are also other parts, such as the

bore of the barrel, that you don’t want to rust. Therefore, it’s

very important that you coat the bore with a suitable protec-

tive grease and then insert tight-fitting wood plugs in both

the muzzle and the chamber. These plugs must keep out

both moisture and the rust blue solution, and at the same

time, keep the oil or grease in the bore from leaking out.

If you have the idea that I am not very enthusiastic about

traditional rust bluing, you’re 100 percent correct. It’s not a

process that I would encourage you to get involved with until

you are a well-established, very experienced gunsmith.

Nitre Bluing

Materials and Equipment Required

Tank for nitre salts. A good tank for nitre salts is the

6″ � 6″ � 10″ black iron tank sold by Brownells. You can

use other containers, such as cast iron pots. Just make sure

that the container is sturdy enough to withstand the heat,

and that it doesn’t leak. Don’t use aluminum containers as

the salts will eat through the aluminum.

Metal Finishing84

Metal Finishing 85

Metal bucket or similar container for a quench tank.

You should fill this container with clean, room temperature

water. Don’t use a plastic container because the hot work-

piece could melt the plastic. Also, make sure that your con-

tainer is large enough to effectively cool the workpiece. If it’s

too small, the workpiece will heat up the water in the quench

tank. A 21/2 gallon metal bucket is about the ideal size.

Container for warm water rinse. Again, you could use a

metal bucket for the warm water rinse.

Water-displacing oil and suitable container. Use these

items for oiling the workpiece after you complete the bluing.

Heat source. You could use a Coleman camp stove, but a

regular gas ring burner is best if you plan to do quite a bit of

nitre bluing.

Lead thermometer. A standard bluing thermometer won’t

measure the high temperature encountered in nitre bluing.

A lead thermometer, like those used for bullet casting, will

register up to 1000°F. These are available from Brownells.

Black iron wire. You use this wire to suspend parts.

Stainless steel or black iron screen wire. This material

is used to make a basket to hold small parts, pins, screws,

and so on.

Stainless steel dipper. A dipper is necessary for adding

nitre salts to the tank.

Rinse tank brush and steel wool. Use either #0 or

#00 steel wool to rub air bubbles off the surface of the

workpieces.

Nitre salt. The amount of nitre salt required will depend

upon the size of your salts container. Brownells sells nitre

salts in 20 pound pails, which is more than enough for the

6″ � 6″ � 10″ tank.

Cleaner. I recommend the use of 1,1,1 trichloroethane. By

carefully cleaning the workpiece with this you can easily

remove any dirt, grease, or oil that might cause problems

with your salts.

Safety equipment. Safety equipment should include Temp-

Tec gloves, a full face shield, a heavy-duty shop apron, a

long-sleeved100 percent cotton or wool shirt, rubber boots,

and a navy-stylewatch cap.

Procedure for Nitre Bluing

Begin by placing your clean, dry salts tank over the heat

source and filling it approximately 3/4 full with nitre salts.

Turn on the heat source. As the nitre salts heat up to

approximately 275°F, they’ll begin to liquefy. Since the dry

granular salts take up more space than the liquefied salts,

the level in the tank will drop. Use the stainless-steel dipper

to gradually add additional salts until you reach the desired

level of liquid salts. Never add more than one dipper at a

time, and always allow it to melt before adding more.

Install your thermometer at this point. Remember that you

can get different colors at different temperatures. Bluing will

begin at temperature between 600°F to 650°F. Don’t allow

the nitre salts to go over 900°F as the salts will begin to

break down at that temperature.

You control the temperatures for nitre salts, unlike those for

caustic salts, by regulating the heat. If the liquid starts to get

too hot, just turn down the heat to stabilize the temperature.

Make sure that your workpieces are clean and absolutely dry.

Never allow any water or moisture to enter the salts tank. If

this happens, the water could convert into steam and cause

an eruption of the salts.

Place the parts to be finished in the salts tank at the appro-

priate temperature (depending on the color you want to

achieve). Normally, the workpieces will color within 5 to 15

minutes. The liquid salts solution is clear, so you can easily

observe the color of the workpieces. When they reach the

desired color, remove the workpieces and place them in

the quenching tank. At this point, you can recheck your

workpieces for proper color. If everything is fine, scrub the

workpieces in hot water to remove all traces of nitre salts

and then transfer the parts to the water-displacing oil.

Metal Finishing86

Metal Finishing 87

A problem that you may encounter in nitre bluing is white

spots on the workpieces. This occurs when you place the

workpiece in the bath and some salts crystallize on its surface.

As the workpiece heats up, the crystallized salts melt, but

small air bubbles remain on the workpiece. These bubbles

effectively insulate the surface metal and lead to the white

spots, or discoloration.

If this occurs with small parts, you can sometimes agitate

them in the bath and cause the air bubbles to break from

the metal surface. On larger parts, as soon as the crystals

melt, remove the parts from the bath and very quickly give

them a light wiping with fine steel wool. Do it only once but

very thoroughly. When you return a workpiece to the salts

bath, the bubbles shouldn’t reform because you have, in

effect, preheated the workpiece.

Presently, Brownells is the only gunsmith supply company

I know of that offers nitre salts. These are clean, high-quality

salts, especially formulated for nitre bluing. Brownells also

offers a detailed instruction booklet for this process.

Note: You can allow nitre salts to solidify in the bluing tank.

Used judiciously, you can reheat them and use them time

and again for several years.

Browning

Materials and Equipment Required

Heat source. You can usually use a small handheld

propane torch available at most hardware stores as a heat

source. I often use my oxyacetylene torch. Although I’ve yet

to try it, I believe that you could use a heat gun. The Seely

S1-1500D will produce hot air up to 1100°F. That’s hot!

Metal Finishing

Rack or holder for the workpiece. Since I normally use

browning on muzzle-loading barrels, I have a 2″ � 4″ board,

a little over 2 feet long, in which I placed two pieces of coat

hanger wire. I shaped the pieces of wire somewhat like the

letter M. The center portion of the wire dips down just

enough to allow the barrel to rest there securely. This gives

me good access to the full length of the barrel and permits

turning of the barrel as required. Small parts, such as lock

plates and hammers, are simply held in small vise grip pliers.

Swab to apply browning solution. Shop Swabs sold by

Brownells are ideal for applying the browning solution. These

swabs have a wire handle and are inexpensive and easy

to use.

Browning solution. There are several browning solutions

on the market that do a fine job. One that’s easy to use and

readily available is the Birchwood Casey Plum Brown.

1,1,1 trichloroethane. You use this cleaner to wipe down

the workpiece and remove all traces of oil or grease. As with

bluing, the cleaner your workpieces, the better your final

result.

Rust-preventive oil. After the browning process is complet-

ed, rust-preventive oil should be applied to prevent further

rusting.

Procedure for Browning

Prepare the workpiece as you normally would for bluing or

any other metal finishing. It’s not necessary or even desirable

to polish much higher than 300 grit. Browning actually takes

better to a rougher surface than it does to one that has a

high polish. Be sure to thoroughly clean the workpiece with

1,1,1 trichloroethane to remove all oil and grease.

Place the workpiece in your holder and gradually apply heat.

Do this slowly and evenly over the entire part. Keep applying

heat until a drop of water will just sizzle when it touches the

surface of the part.

You can now begin to apply the browning solution with your

swabs. Keep the swabs saturated and make long, continuous

applications down the length of the barrel. Try not to have

overlaps or runs. Make sure that you continue to apply heat

and don’t permit the parts to cool.

88

Metal Finishing 89

The more coats of browning solution you apply, the darker

and richer the finish. When the piece reaches the desired

finish, stop. Let the parts cool and wipe them down with a

soft clean cloth. Then, apply a generous coating of a good

rust-preventive oil.

As with traditional rust blues, the humidity in the air may

have an effect on your finish and how well the solution works.

It seems to work best on warm days when the humidity is

between 80 and 90 percent.

Electroless Nickel Plating

Materials and Equipment Required

Electroless nickel plating chemicals. Although these

chemicals may be available from other sources, the most

commonly used materials are those provided by Brownells.

They made a special effort to develop and offer plating systems

with the small shop in mind. Also, like their bluing instruction

booklet, Brownell’s plating instructions are extremely detailed,

yet very easy to follow. If you’re interested in electroless nickel

plating, contact Brownells.

Flowing cold water tank. The cold water tank can be any

container large enough to hold your workpieces. Make sure

the flow of water through the tank or container is vigorous

so that you have a constant source of clean, fresh water.

Hot cleaner tank.If you’re already set up to do caustic salt or

hot water bluing, you can use your existing cleaner tank. The

size of your workpiece will determine how large a tank you

should use.

Hydrochloric acid, 32 percent. Hydrochloric acid,

32 percent, is the same as Muriatic acid, 18° Baumé.

You use this acid for the pickling step.

Pickling tank. You can use virtually any container for a

pickling tank except one made of steel. Use an inexpensive

gallon-sized Rubbermaid wastebasket. Be sure to set the

pickling tank inside a second container just in case there

are spills or leaks.

Nickel plating tank.While large Pyrex containers are ideal for

nickel plating tanks, they’re also expensive. The most eco-

nomical tank to use is a porcelain enameled steel tank, the

kind your grandmother used to make pickles.

Motorized agitator for the nickel solution. You must

constantly stir the plating solution so that it flows gently and

evenly over the workpiece and deposits the nickel on the

workpiece surface. Your agitator should have a speed control

so that you can govern the flow of the plating solution.

Heat source for cleaner and plating ranks. If you’re

doing small work such as handguns and therefore have small

tanks, a Coleman camp stove would be a fine heat source.

Make sure that it’s large enough to provide heat to both

tanks at the same time.

Nylon spoon. Use a nylon spoon for mixing and stirring the

solution.

Nylon or polypropylene measuring cup set.You’ll need meas-

uring cups to measure out the various chemicals.

Distilled water. Because electroless nickel plating is very

sensitive to contaminants, use distilled water for all water

applications except the flowing cold water rinse and the hot

cleaner.

1,1,1 trichloroethane. Use this cleaner for precleaning

your parts before you immerse them in the hot cleaner tank.

It’s just an extra step to ensure that you don’t contaminate

your solution.

Hot cleaner. Brownell’s Dicro-Clean 909 is effective and

inexpensive, and it won’t etch your workpiece.

Bluing thermometer. You need a thermometer to monitor

the temperature in the various solutions.

Black iron wire. Use black iron wire to rig up handles for

the workpieces.

These are the basic items that you’ll need to begin electroless

nickel plating. You could add additional items such as a

nickel stripping solution, storage jugs for the chemicals,

and so on. If you’re serious about getting into plating, give

Brownells a call. They’ll be more than happy to discuss your

needs with you.

Metal Finishing90

Metal Finishing 91

Procedure for Electroless Nickel Plating

Begin by preparing the plating solutions according to the

manufacturer’s instructions. It’s very important that you

follow the manufacturer’s instructions to the letter. Don’t

get creative. If you don’t understand something, stop. Call

the manufacturer or vendor of the plating materials and let

them answer your questions.

Make sure you thoroughly clean and rinse all containers

before use. You don’t want to take a chance on contaminat-

ing your solutions.

After polishing your parts, preclean them with trichloro-

ethane. Next, place them in the flowing cold water tank for

10 seconds. This removes all traces of the trichloroethane.

Place the part in the pickling tank for three seconds. The

pickling tank contains hydrochloric acid as well as a special

chemical activator. Mix this solution with special care following

the manufacturer’s instructions. Don’t heat this solution. The

pickling step is important because it prepares the surface to

take the plating. When a part enters the pickling solution, it

should “gas,” or give off bubbles. These bubbles indicate that

the pickling solution is working properly.

Following the pickling, return the parts once more to the

flowing cold water rinse for three seconds. Again, the objective

is to remove all traces of the pickling solution.

Next, place the parts in the hot cleaner, the Dicro-Clean 909,

for 10 to 15 minutes. Heat the 909 solution 180°F. Use

about 8 ounces by weight of the 909 per gallon of water

in your cleaning tank.

Next, return the part to the flowing cold water tank for 5

seconds. Agitate the parts to remove any traces of the 909

solution. Put the parts back into the pickling tank for 5 sec-

onds. Again, you should look for gassing to indicate that the

pickling solution is acting on the workpiece. Now return the

part to the flowing cold water tank for 3 seconds to remove

any residual acid.

Next, place the part in the heated, mechanically-agitated

nickel plating solution. If you’re using the Brownell’s product,

heat this tank to 195°F. Leave the parts in the tank for 45

minutes. This will ensure that a 3/8 millimeter layer of nickel

is deposited. Do not remove the parts from the plating tank

once the process has started.

After you complete the plating step, return the part to the

flowing cold water tank for a full 2 minutes. Then, remove

the parts and inspect them. The process is complete.

As you can see, this is a very lengthy and involved process.

There’s really much more to it than stated here.

Parkerizing

Materials and Equipment Required

Parkerizing solution and sealant. There are a number of

ready-mixed parkerizing solutions available. The one that I

have used most is Amer-Lene, produced by Mount Labs, Inc.,

in Altamonte Springs, Florida. Amer-Lene is a zinc phosphate

solution that provides a durable, gray finish. You can change

the gray color to black simply by running the parkerized part

through a hot caustic salts bath.

Stainless steel container for parkerizing solution. The

container should be large enough to hold the workpieces and

the parkerizing solution. Don’t use black iron or mild steel

for this tank, as you’ll parkerize your tank rather than the

workpiece.

Container or tank for heated cleaner. This container

could be either black iron or stainless steel.

Heated cleaner. Brownell’s Dicro-Clean 909 is excellent for

thispurpose.

Heat source for cleaner and parkerizing.If you use small con-

tainers, a Coleman camp stove is adequate for this purpose.

1,1,1 trichloroethane. You use trichloroethane as a

precleaner.

Metal Finishing92

Metal Finishing 93

Bluing thermometer. You need a thermometer to monitor

the temperature of the 909 solution and the parkerizing

solution.

Black iron wire. Use black iron wire to provide a means of

inserting and removing parts from the various solutions.

Cold water rinse tank and a natural bristle brush.

Safety equipment. You should wear rubber gloves, a full

face shield, a long-sleeved cotton or wool shirt, and a shop

apron when working with parkerizing chemicals.

Procedure for Parkerizing

Begin by preparing the heated cleaning solution. Use approx-

imately 5 ounces of 909 per gallon of water. Heat this solution

to 180°F, and stabilize it at that point.

The Amer-Lene parkerizing solution is mixed at the rate of 3

ounces per gallon of water. Make sure you mix enough to

cover your parts and to provide a bit of latitude for any evap-

oration that might occur. Heat the solution to between 165

and 185°F and stabilize.

Properly prepare your workpieces by blasting or polishing.

Then preclean them with trichloroethane. Remove old traces

of blasting dust and polish. Following this, place the parts in

the 909 bath for approximately 15 minutes.

After removing the parts from the 909, rinse them thoroughly

to remove all traces of 909. Use a natural bristle brush to

scrub the parts.

Now, place the parts in the Amer-Lene solution for 3 to 5

minutes. Occasionally move the parts around. It’s also a

good idea to stir the solution occasionally to ensure that

the zinc in the solution remains evenly distributed.

After coating, remove the parts from the parkerizing solution

and place them in the flowing cold water rinse for about 1

minute. Do not allow the parts to dry when transferring them

from one tank to another. Do so as quickly as possible.

Remove the parts and dry them with a clean dry towel. Then

spray them with the Amer-Lene Seal. Wipe away any excess

seal. This completes the process.

Baking Lacquer

Materials and Equipment Required

Baking lacquer. At the present time, two colors of baking

lacquer are available, black and clear. You use the black to

color nonsteel parts, such as Remington 870 or 1100 trigger

guards or Mossburg 500 receivers. Use the clear lacquer pri-

marily for covering an engraved surface or plain brushed

metal, when you want a French-gray-type finish. This type

of finish is very similar to that found on some Browning and

Beretta over and under shotguns.

Baking lacquer thinner. Baking lacquer thinner is absolute-

ly necessary to clean up your painting equipment or to thin

out the lacquer for proper application.

1,1,1 trichloroethane. Use this solvent to clean the work-

pieces prior to applying the baking lacquer.

Paint sprayer. It’s best to use a good quality airbrush. This

provides a finer spray that’s more controllable than most reg-

ular paint guns. Be sure that if you use an air compressor, it

has a moisture trap and can deliver clean, dry air. Moisture

in the air will contaminate the lacquer.

Heating oven. You need an oven to cure the baking lacquer.

You can do this in your kitchen stove or, if the parts are

small enough, in a small toaster oven.

Procedure for Baking Lacquer

Prepare your workpieces by polishing, wire wheeling, or bead

blasting. Be sure to thoroughly clean the workpieces with

1,1,1 trichloroethane to remove any dust, polish residue, or

oil that would interfere with the adhesion of the lacquer.

Adjust your airbrush to use the lacquer. Normally, you mix

the lacquer with the thinner, the preparation being four parts

lacquer to one part thinner. Be sure to spray a bit on a test

piece to ensure that the airbrush works properly. If all is

well, spray the workpiece. Use a number of thin coats rather

than trying to cover the part with one or two thick coats.

Metal Finishing94

Metal Finishing 95

After completing the spraying, allow the workpiece to dry for

about 2 hours. You can then place the workpiece in a pre-

heated oven at 325°F for 20 minutes to bake or cure. The

process is complete after curing.

Flame Coloring

Materials and Equipment Required

Oxyacetylene welding outfit. An oxyacetylene welding out-

fit is the primary piece of equipment required for flame color-

ing. You should have a small- to medium-sized hand piece

that you can easily move about. (The one I use is a Victor

Model 100.) The tip you use should produce a fairly small

flame; too large a flame will obscure your work.

Quenching oil. You use a special heat-treating oil with a

very high flash point both to coat the workpiece prior to

heating and to quench or cool it during the process. I use a 5

gallon bucket of this oil with the lid removed.

Heavy leather gloves. Gloves are an absolute must when

you’re working with a torch. They’ll prevent your hands from

being burned or overheated.

Vise grip pliers. You can use vise grip pliers to hold the

workpieces. When the pliers are locked, there’s little danger

of dropping the workpiece or losing it in the quenching oil.

Clear acrylic spray or clear baking lacquer. You use

spray or lacquer to coat the part to protect the flame color

finish.

1,1,1 trichloroethane. Use trichloroethane as a solvent

and cleaner prior to flame coloring and as a cleaner prior to

applying the acrylic spray or baking lacquer.

Soft cotton cloth and cotton balls. Use cotton with

thetrichloroethane.

Procedure for Flame Coloring

First, polish the workpiece, such as a cast iron, single-barrel

shotgun receiver, to at least a 400-grit finish. Then, clean it

thoroughly with trichloroethane to remove all traces of polish

and/or other contaminants. Attach the vise grips to a portion

of the workpiece that can’t be seen when the gun is assembled.

Make sure to securely lock the vise grips in place.

Set the quenching oil container in a convenient location.

You may find it convenient to sit on a small stool with the

quenching oil directly in front of you. Put on your gloves and

turn on your torch. Adjust the flame so that it’s to inch long

and has a clean blue color.

Pick up the workpiece with the vise grips in your left hand

(if you are right handed) and hold the torch in your right

hand. Coat the workpiece in the quenching oil by dipping it

into the oil container. Pull it out and allow most of the oil to

drip back into the container.

Position the torch flame just above the surface of the work-

piece. You’ll notice that colors immediately begin to appear.

Move the torch quickly across the workpiece, “running” the

colors. Don’t stop the torch or touch the surface with the

flame. If you do, you’ll have an unsightly brown or dark,

burned-looking spot. After making your pass with the torch,

plunge the part in the quenching oil.

After a few seconds, pull the workpiece out of the oil and

repeat the process. Be very careful about working near edges

or thin parts, as they’ll heat more rapidly.

Practice and experiment until you can create an attractive,

pleasing finish. Practice and the willingness to vary your

technique with the torch are the secrets to flame coloring.

If you “goof” and the appearance of the workpiece isn’t satis-

factory, don’t worry. First, clean the oil off the workpiece. Use

a buffing wheel on the piece for a minute or two to remove all

traces of your work. You can then easily do the work over.

Metal Finishing96

Metal Finishing 97

When you complete coloring a part to your satisfaction, turn

off the torch. Don’t remove the vise grips. Clean the work-

piece first by bathing it in trichloroethane. Use some

trichloroethane on the cotton balls to give the flame-colored

area a very, very gentle wiping. Be careful: the flame coloring

is very fragile at this point.

When the trichloroethane dries, use the acrylic spray or

baking lacquer to coat the part. This will protect the flame-

colored area.

Jeweling

Materials and Equipment Needed

Drill press. You’ll need either a floor or bench-mounted drill

press to perform jeweling. The drill press spins the jeweling

tool.

Jeweling jig or fixture. If you wish to jewel rifle bolts, you

must have a fixture to hold the bolts and position them prop-

erly for contact with the jeweling tool. Presently, only two are

on the market, the Wilcox Bolt Jeweling Fixture and the B-

Square Jeweling Jig. The Wilcox tool is a very sophisticated,

precise gunsmithing tool and is the one I prefer. Both are

available from Brownells. You can jewel other parts, such as

revolver hammers or triggers, while they’re secured in a small

machinist vise.

Jeweling tool. A jeweling tool can range from the Menck

tool mentioned earlier to small wire brushes mounted on a

tiny shaft. Depending upon the tool you choose, you may

need additional equipment such as cutting oil and engine

turning abrasives. I prefer the Mensch tool since it uses

cratex abrasive rods and eliminates the need for these

extra items. It also produces more uniform swirls.

Procedure for Jeweling

Begin by polishing the workpiece to a minimum of a 400

grit. Actually, the higher the polish, the more distinctive the

jeweling and the better it shows up. Don’t skimp on your

preparatory polishing. Do the very best job you can.

Set up your jeweling tool in your drill press according to the

manufacturer’s instructions. I have my drill press set to

between 650 and 1,000 rpm. I’ve never seen any advantage

in spinning faster than that.

Place the workpiece under the drill press chuck and secure it

so that it won’t move. Lower the chuck and check the posi-

tion of your workpiece. If you’re jeweling a Smith and Wesson

revolver hammer, for example, you’ll want your first swirl to

be right at the edge on the side of the hammer. Also, place

the swirl as near the top of the hammer as possible.

With the workpiece properly set up, turn on the drill press

and lower the chuck so that the jeweling tool contacts the

surface of the workpiece. Hold it against the workpiece for a

count of five. Then raise the chuck. Reposition the workpiece

so that your next swirl overlaps the first swirl by about one

third. Lower the chuck until the rotating tool again contacts

the workpiece for a count of five. By holding the jeweling tool

against the workpiece for equal lengths of time, the swirls

will be uniform and of equal depth. Use a light to moderate

touch with the chuck. Try not to allow the jeweling tool to

flare out (Figure 38).

Keep repeating this sequence of steps until you cover the

work-piece with swirls. Try to make your swirls absolutely

consistentand uniform. If you make a mistake, stop. Repolish

the workpiece and start over again. Practice with

scraps of steel until you develop your technique

and have a good feel for this process. The more

you do it, the better you become.

After jeweling a part, be sure to clean it thor-

oughly to remove any traces of abrasive or grit.

Metal Finishing98

FIGURE 38—Shown are the basic steps injeweling. Keep in mind that you can overlapthe swirls or circles any amount. The illus-tration shows about a 50 percent overlap,but you can have less.

Metal Finishing 99

Cold Bluing

Materials and Equipment Required

Cold bluing solution. As mentioned earlier, there are

numerous cold blues on the market. The following companies

produce excellent cold blues: Brownells (Oxpho-Blue and

Dicropan T-4), Birchwood Casey (Super-Blue), and Gun Parts

Corporation (44-40 Blue). I find that Brownell’s Oxpho-Blue

is more durable and abrasion resistant than many other cold

blues. Cream cold blues are now beginning to be marketed in

addition to the standard liquid solutions. I prefer the liquid,

as I find it easier to use.

1,1,1 trichloroethane. Use trichloroethane to clean and

degrease the workpieces. Although some cold blues will work

through thin coats of oil, it just makes good sense to have

the workpiece as clean as possible to permit the full strength

of the cold blue to work on the base metal.

Cotton swabs or cleaning patches. Use these to apply the

cold blue to the workpiece.

#0 Steel wool. Use steel wool to burnish and even out the

cold blued finish.

Note:Prior to using steel wool, soak it in trichloroethane for a

few minutes to remove oil residue left from its manufacture.

Then allow a few minutes for the trichloroethane to evaporate.

Clean cotton cloth. You need a cloth to dry the workpiece

and remove excess cold blue.

Procedure for Cold Bluing

Suppose you’re going to reblue a .22 rifle barrel. Start by

polishing the barrel with abrasive to approximately a 320 to

400 grit finish. Then, thoroughly clean the barrel with 1,1,1

trichloroethane.

Next, make a swab with three or four cleaning patches and

saturate it with the cold blue. Wipe down the entire barrel

as quickly as possible, avoiding runs or overlaps. Allow the

cold blue to work without drying for about 60 seconds. Then,

wipe it dry with a clean cotton cloth.

When the barrel dries completely, burnish it vigorously with

the #0 steel wool. Pay particular attention to areas of uneven

color. Repeat the application of the cold blue followed by a 60

second waiting period for the chemical action of the bluing to

take place. Wipe down the barrel with the cotton cloth again,

and then burnish with #0 steel wool. Keep repeating this

sequence until you have the finish you want.

Here are a few hints and suggestions that will help you avoid

trouble with cold bluing. First, don’t contaminate the cold

blue in the bottle. If you’re going to use some, pour it into a

shallow dish or saucer. Don’t return the unused portion to

the bottle; throw it away. Never allow the lid to stay off the

bottle any longer than is absolutely necessary. Some of the

components can evaporate and weaken the solution. Finally,

if the solution is more than a year old, get rid of it! Use a

fresh, new full-strength solution.

Conclusion

As a gunsmith, you should concentrate your efforts on devel-

oping your skills and techniques in providing finishes such

as caustic salt bluing, hot water bluing, browning, parkeriz-

ing, baking lacquer finishes, and jeweling. Easily, 95 percent

of your customers will need these types of finishing services.

It’s certainly in your best interest as a gunsmith and as a

businessperson to concentrate your efforts in these areas.

As you develop your business and your shop grows, you

can begin to offer other, more exotic finishes. You might also

simply opt to contract with other specialized companies or

gunsmiths that offer the more unusual finishes.

Note:In this study unit, you also studied anodizing, electrolytic

plating, color case-hardening, and Teflon coating. The various

reasons whyit isn’t practical or possible to offer these finishes

were explained. With anodizing, equipment powerful enough

to do large gun parts either isn’t available or is terribly

expensive.

Electrolytic plating also requires expensive equipment and

involves using hazardous chemicals which are difficult and

costly to ship.

Metal Finishing100

Metal Finishing 101

Color case hardening requires use of an enormous heat-

treating furnace to case harden receivers and large gun

parts. Also, specific information about and directions for

performing this process are not currently available.

Finally, Teflon coating must be licensed by DuPont, the

owner of this process. In addition, it requires extensive costly

equipment.

Good luck with the remainder of your gunsmith program.

Whether you remain a hobbyist or enter the trade as a

full-time professional, always strive to improve the quality

of your work. No one is perfect, but you can surely try for

that perfect finish.

Metal Finishing102

Self-Check 6

1. Why should you use a damp box for traditional rust bluing?

__________________________________________________________________________

2. What causes white spots on nitre bluing workpieces?

__________________________________________________________________________

3. When applying a browning solution, what should you do to get a darker finish?

__________________________________________________________________________

4. What type of tank should you use for parkerizing?

__________________________________________________________________________

5. How is baking lacquer best applied?

__________________________________________________________________________

6. What should you use to protect a flame-colored surface?

__________________________________________________________________________

7. Why do you hold the jeweling tool against the workpiece for the same amount of timeand with the same amount of pressure for each swirl or circle?

__________________________________________________________________________

Check your answers with those on page 106.

103

Self-Check 1

1. Your customers will often ask for your advice and sug-

gestions as to what finish would be best for their needs.

2. No one knows how the metal on the first firearm was

finished, or if it had any type of protective or metal finish

at all.

3. No, some used rusting techniques, some used paints,

and some used heat coloring.

4. In most cases, the metal was left unfinished (in the

white).

5. R. H. Angier’s Firearm Bluing andBrowning

6. Norm Flayderman’s Guide to Antique American Firearms

7. Never do anything to a collectible firearm that will lower

its value.

Self-Check 2

1. Sodium hydroxide, sodium nitrite, and sodium nitrate

are the major components of caustic bluing salts.

2. It will very quickly dissolve.

3. Some advantages of hot water bluing are

• They’re more durable and abrasion resistant.

• They have no effect upon soft solder.

• They don’t require as much equipment to apply.

• The bluing solutions aren’t usually as hazardous.

4. No, they’re normally used only on chromemoly steels of

the type found on modern firearms.

5. Some type of corrosive acid

6. It will be very difficult to get metal to rust when the level

of humidity is less than 60 percent.

7. Heat

8. The traditional rust blue is more durable and abrasion

resistant.

An

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Self-Check Answers104

9. 400

10. Handguns

11. To hold oil against the surface of the steel

12. The acids used in parkerizing will etch steel.

13. The trigger guard on a Remington 870 is made of alu-

minum and can’t be blued with normal bluing solutions.

14. With an airbrush

15. Only quenching oil

16. Give the part a coat of a clear polyurethane or clear

baking lacquer.

17. Jeweling is primarily a decorative finish.

18. It will sometimes discolor or remove the original blued

finish.

19. By removing any grease, oil, dirt, or other contaminants,

the bluing can react more directly to the base metal.

20. There’s a risk of the part bending or warping as it’s

heated and then quenched.

Self-Check 3

1. Metal finishing will enable you to upgrade or improve

the appearance of some used guns, thereby increasing

their selling price.

2. Contact all gun clubs in your immediate area.

3. They help the customer understand what you can do

and the services that you offer.

4. No one likes to be surprised by a big bill. An estimate

will help to avoid problems and conflicts when you finish

the job.

5. Yes, not only for your own safety and liability, but also

to enable you to be sure that when you return the gun

to its owner it works properly.

6. If the stock has been burned or charred, it was

undoubtedly exposed to too much heat and you should

consider it unsafe.

Self-Check Answers 105

7. Vinegar

8. A Material Safety Data Sheet is a document made up by

the manufacturer of a product that lists any hazardous

components or chemicals used in that product. It also

provides information on proper disposal and possible

harmful effects. Most important, an MSDS will tell your

doctor how to treat a person who has had external or

internal contact with the chemical.

9. A full-face shield, heat-resistant gloves, a neoprene

apron, rubber boots, a long-sleeved shirt, heavy-duty

long cotton or denim trousers, and a cap

Self-Check 4

1. In most cases, you should completely disassemble the

gun. Normally, leave only the barrel attached to the

receiver. You must remove all pins, springs, screws,

and other internal parts.

2. No one can know or remember everything about every

gun ever made. Reference books help by putting lots of

information at your fingertips.

3. Gasoline is a fire hazard and you should never use it in

a shop.

4. You save a lot of time and you don’t remove as much

steel from the gun as you would with an abrasive

procedure.

5. Sandblasting

6. Stitched muslin, loose muslin, and felt

7. The hard wheels are more aggressive.

8. The direction of rotation and the grit of the polish used

on the wheel

9. By polishing across the grit marks, you’ll quickly erase

them.

10. You’re pressing against the buffing wheel too hard with

the workpiece. You’ll only need minimal pressure if you

set up the wheel properly.

Self-Check Answers106

Self-Check 5

1. Use only a black iron or mild steel tank.

2. Multiply length by (width minus 2) by height. Then

divide the product by 231. This will give you the capacity

of the tank in gallons.

3. No. The caustic salts will eat away the stands and cause

the tanks to fall.

4. Located it at least 1 inch from the bottom of the tank

and approximately midway along the length of the tank.

It should also be at least 1 inch from the side of the

tank.

5. Add salts to the bath.

6. The heat accelerates the chemical reaction of the bluing

solution.

7. Contamination from oil or grease

8. No. Once inserted in the tank, you shouldn’t remove the

part until completed.

Self-Check 6

1. It allows you to control temperature and humidity, vital

factors in rust bluing.

2. Air bubbles

3. Apply more coats of finish

4. A stainless-steel tank

5. With an airbrush

6. A clear acrylic spray or clear baking lacquer

7. To ensure that the swirls are identical

107

925 Oak Street

Scranton, Pennsylvania 18515-0001

Metal Finishing

When you feel confident that you have mastered the material in this study unit, complete the following examination. Then submitonly your answers to the school for grading, using one of the exami-nation answer options described in your “Test Materials” envelope.Send your answers for this examination as soon as you complete it.Do not wait until another examination is ready.

Questions 1–20: Select the one best answer to each question.

1. As a gunsmith, it’s important for you to have a good basic knowledge about metal finishes because

A. your customers and friends will ask you for information aboutdifferent finishes.

B. you must know about finishes to get a Federal FirearmsLicense.

C. every gun must be refinished at some time.D. refinishing services are almost essential if a gunsmith shop

is to be successful.

EXAMINATION NUMBER:

Whichever method you use in submitting your examanswers to the school, you must use the number above.

For the quickest test results, go to http://www.takeexamsonline.com

Ex

am

ina

tion

Ex

am

ina

tion

02531000

Examination108

2. Suppose that as you’re bluing a workpiece with a caustic salt, your workpiece develops ared smut when you transfer the piece from the salts tank to the cold water rinse. What isprobably causing the problem?

A. The parts are rusting in the salts tank.B. There’s not enough boil at the correct temperature.C. The salts solution is too new.D. Your cold water rinse tank isn’t large enough to cool the piece.

3. In traditional rust bluing, the rusting is controlled by the frequency of carding or wire brushing and by the

A. temperature in your shop. C. age of the gun.B. amount and type of rusting solution used. D. humidity in the damp box.

4. If you need information on old-time gun metal finishes, you should

A. read Shotgun News and The Gun List.B. obtain copies of Firearm Bluing and Browning and The Gunsmith’s Manual.C. read as many of the current gun magazines as you can.D. talk to collectors of such firearms.

5. How can you raise the temperature of caustic salts?

A. Increase the heat. C. Add water.B. Add salts. D. Use a stainless-steel tank.

6. To blue a part with nitre salts, you must heat the salts to

A. between 290 and 315°F.B. between 600 and 650°F.C. the point at which the salts will turn into a liquid.D. the point at which the salts reach a rolling boil.

7. When compared to some of the old-time metal finish formulas, the modern commercial finishing compounds are

A. not as good.B. better, but more time-consuming.C. safer and easier to use.D. cheaper, but less readily available.

8. If the temperature in your caustic salts tank starts to get too high, you should

A. cut down the heat. C. remove the part being finished.B. add salts to the tank. D. add water to the tank.

9. Browning is a traditional metal finish that’s popularly associated with

A. handguns. C. cheap .22 rifles.B. military bolt-action rifles. D. muzzle-loading firearms.

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10. What will happen if you blued an older soft-soldered, double-barrel shotgun in a causticsalt bath?

A. Nothing will happen.B. The caustic salts will attack the solder that holds the barrels together.C. The salts will turn the barrel gray.D. The salts will cause the barrel to oxidize.

11. What should you remember to do when using a draw file?

A. Always use file chalk on your file.B. Keep your file well oiled when in use.C. Move the file quickly back and forth over your workpiece.D. Cut only when you push the file away from you.

12. You can blacken parts with a parkerized finish by

A. heating the solution to a higher temperature.B. running them through a caustic salts bluing bath.C. using nitre bluing salts at 175°F.D. leaving the parts in the parkerizing solution for longer than the recommended 3 to

5 minutes.

13. Prior to World War II, most double-barrel shotguns were made with

A. Damascus barrels and ribs.C. welded barrels and ribs.B. silver-soldered barrels and ribs.D. soft-soldered barrels and ribs.

14. What is one important point to remember when doing restoration work?

A. Employ only those techniques and materials that the original builders used.B. Use newer finishes as they are better.C. Replace as many old parts as possible.D. Tell your customer you can’t provide an estimate because there are too many variables

in restoration work.

15. Why should you always use a sealed cabinet for glass bead blasting?

A. It will help keep your shop clean.B. It enables you to save the glass beads.C. It protects you from breathing the glass dust created during the bead blasting.D. It allows you to control the moisture in the box.

16. You should never do any work on a firearm that will

A. make it look old. C. alter its appearance.B. make it easier to use. D. lower its value.

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17. What is one key to good promotion and advertising?

A. You should be very low key; don’t attract a lot of attention.B. You don’t need to do anything; if folks need your services, they will find you.C. You must be energetic and use as many different ways as possible to inform the public

of your shop and of the services you offer.D. Begin by offering your services at very low prices to attract customers to your shop.

18. When taking apart a gun you’re unfamiliar with, you should

A. first remove every pin and screw you can see.B. get some detailed disassembly information on the gun.C. ask a friend for help.D. always place all the parts in one basket.

19. If the manufacturer or seller of an item, such as bluing salts, refuses to furnish a MaterialSafety Data Sheet, what should you do?

A. Don’t worry; it’s not that important.B. Use one from a similar product.C. Use some other product made by a manufacturer that will furnish a Material Safety

Data Sheet.D. Research your reference library to find information on the application of the item you

are using.

20. If a gun has been in a fire, what is a good rule of thumb to determine whether or not it’sstill safe to use?

A. If it still has live ammunition in it, it’s okay.B. If the wood stock has not been burned or charred, that’s a good indication that it has

not been exposed to excessive heat.C. If there’s any smoke or water damage, the gun should be considered unsafe.D. A test fire is the only way to determine if the gun is safe to use.