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REQUIREMENTS
FOUNDRY PRACTICE
To obtain a Merit Badge for Foundry Practice, a Scout must:
1. (a) Make a .freehand drawing of a flask used for bench mould· ing in the foundry.
(b) Describe same llQk. • ·
2. (a) Show by aection sketch a mould 'of a plaai 12" long, 6" wide, 111 thick widi gaw -ud V8iiiil; · ·
(b) Construct 'tbe m.alf ' ' 3. Make a perspecti\ie ~ of a pulley pattern 6'' in diameter,
2" face, the centel' to be cored 2" by use of core. prina. 1 .
4. Cobstrw:it a ~ pattern and core box as per s1cetch outlined in question 3; d8e . .tvinbge rule for the metal ueed-GRA Y IRON, BRONZJ!r Cllt 'Ba.ASS. Chanae measurement& to allow for fuiiah all over casting and pn>per ~alt lor removing pattern from ipould.
S. bl!ICl'iM how a cupola operaw1
6. (a) ~a process for deaning one of the above castings When ~ ~ mould. ~
(b') ~ OD~ of the above camnp.
'J, Delcrihe. die propertjes in lllD.d that are 'Lest suited for foundry use and wll how to pre~ sand fqr use.
8. Tell wb.at .important 1afety precautiona lhould 'be tiken to protect the workers in a foun~yAhe employer--by the employee?
NO'l'B: in each t:ue when a 11tould is required tbe pattern must first be made. · ·
"Goltl a for the miatn•-llver for tlae maid! "Copl!.• fa&o the cnfu'maa cunning at bU trade." "Goacll" HJ.ii tha Beren, littins ill hia hall. .,.Bat Iron, Co!cl lioil, la - of them afll"
From the Poem "Cold Iron., in Rewards and Fairies, by Rudyard Kipling. By permission of
A. P. Watt l!I Sons, London, Ens.
Copyright, 1930, by Boy SClOUtl of America
IM-May, 1937
INTRODUCTION
T HIS is one of a series of pamphlets published by the Boy Scouts of America in connection with its Merit Badge scheme. This library on Scout activities and
vocational guidance has been prepared by experts and is frequently revised and brought up to date.
We feel that the Merit Badge Series offers to boys a library that is unsurpassed in helpfulness, technical excellence, and wide range of interest. Much of the material that is here made available at a very moderate cost, it would be impossible to procure at any price elsewhere. Leading authorities have placed their time and knowledge at the disposal of the Boy Scouts as a contribution to the boyhood of America.
It would defeat the purpose of the Merit Badge plan if an attempt were made in the pamphlets to cover the requirements so completely as to make unnecessary the boy's using his own init iative and resourcefulness in seeking further information to enable him to meet the requirements successfully. The material in this pamphlet, however, provides a more comprehensive outline of the subject than would be practical in the Handbook for Boys. The pamphlets suggest the scope of the subjects, and serve as a guide. In each case the Scout should secure further book knowledge for himself and avail himself, on his own initiative, of such opportunities for further study as he can develop in his neighborhood or community, from men who are authorities on the irnbject. Experience shows that men of this type are usually very glad to cooperate w ith boys who show an earnest interest in the subject.
Only the duly registered Scout may qualify for Merit Badges. Second Class Scouts are eligible to take five of a selected list of forty subjects. First Class Scouts may qualify for the entire series.
iii
iv Introduction
Examination for Merit Badges should be given by the Court of Honor of the Local Council and in larger communities by the district Court of Honor, organized so as to reduce to a minimum the necessity of the boy traveling long distances. In no case shall a Merit Badge be awarded unless the Scout has personally appeared before at least three members of the Court of Honor, and either by examination, conducted personally by the .Court of Honor, or upon evidence furnished by a duly appointed expert counselor, demonstrated to the satisfaction of the Court of Honor that the requirements have been complied with in a satisfactory manner. In con;_munities where there is no Court of Honor an Examining Committee of at least three members supervises the Merit Badge Tests.
In all examinations, it should be borne in mind that the purpose of the tests and examinations is not to secure a mere technical compliance with requirements, but rather to ascertain the Scout's general knowledge of subjects studied, and practical rather than book knowledge is desired. A Scout should be prepared at any examination tfor a review covering previous tests given him as well as to demonstrate that he is putting the Scout Oath and Law into daily practice.
With a view of increasing the value of these pamphlets to all boys, and particularly to Boy Scouts interested in securing Merit Badges, an attempt has been made in connection with each subject, to make available facts and information bearing on the vocational value of the subject. It is believed that this practical application in each case makes available a unique contribution to the literature for boys, and will be of great value to parents and teachers as well as boys throughout the whole country.
To further this object, those interested, and having suggestions to offer as to the vocational guidance treatment of any of the more than 100 subjects for which 'Merit Badge awards are' provided are invited to correspond with E. S. Martin, Secretary Editorial Board, The Boy Scouts of America, 2 Park A venue, New York City.
FOUNDRY PRACTICE Definition
Foundry practice is the name applied to that branch of engineering which deals with melting metal and pouring it in liquid form into sand molds to shape it into castings of all descriptions.
CASTINGS
Three Classes of Castings Three classes of castings, each having individual physi
cal characteristics, (such as strength, toughness, durability, etc.), are employed in the manufacture of modern machinery; to wit, those made from gray iron, copper alloys, i.e .. , .brass, bronze, etc., and mild steel. Gray Iron
The bulk of the casting done in the foundries of America is of gray iron, that is, iron which may be machined directly as it comes from the mold without any further heat treatment.
Chilled Iron and Malleable Iron Chilled iron is used for rolling mills, car wheels, etc.,
and malleable iron is used for certain types of hardware in use by manufacturers and builders.
MOLDING
Molding Operations Variously Classified The mold is the essential feature in all foundry prac
tice. A mold is a forin or cavity in a refractory material such as sand, loam or in metal, into which molten metal is poured, and which determines the final shape of the poured metal after it becomes cold. There are four main branches of gray iron molding, judged from the material of which the mold is composed: Green sand work, cover work, dry sand molding, and loam work.
Classified according to size, molding operations are broadly grouped as bench work,,, usually for the lighter
I
2 Merit Badge Examinations
class of castings, and f loor work, for the heavier castings. Another subdivision is hand work and machine w ork,
depending on whether the mold is made by hand or 111
a molding machine.
Characteristics Common to All Molds
Although molds are made in many different materials, and of many different shapes, and by different methods, they are, in their essential characteristics, all alike: they are all made from a pattern, they are supported by and enclosed in a flask, they are formed in a material which will imthstand the heat of the molten metal when it is poured into the mold.
Definitions
A pattern may be made of wood, metal or other mate-rial. 1
Molds, except for the very largest which are bedded in the floor of the foundry, and certain other special kinds of molds, are supported by a'nd inclosed in a flask. This" fl.ask may be made of wood or metal, and may be rigid or hinged, in which latter case it is known as a snap flask.
Snap Flask. From VVendt's Foundry Work.
Foundry Practice 3
If in an article to be cast it is required t hat there should be cavities, or holes, that is, that the cast ings should not be solid, as in the' case of an ordinary pipe, it is necessary that in the inold this cavity should be filled with mater ial which will confine t he metal into those channels w hich will, on the metal solidifying, give the required shape of the article.
The core is t he name given t o the form so inserted in the mold, a s to produce a hollow or cavity in the casting. Cores may be either baked cores, or g r een sand cores.
FIG. 2. Core Oven for Baking Small Cores.
F rom F oundry W or k by William C. Stimpson. Courtesy of the A merica n School.
Core making is a . special branch of the molder's art. Core making supplements molding. It deals w ith the construction of separate shapes in sand which form holes, cavities or pockets in the castings. Such shapes are called cores. They are held firmly in position by the sand of the mold itself.
4 Merit Badge Examinations
Core sand differs from ordinary molding sand. It is shaped in wooden boxes called core boxes. All cores are baked in an oven before they can be used. The w hole detail of their construction. differs so fundamentally from the construction of a mold, that core making is a distinct trade, and frequently is a stepping stone ~o molding. Boys entering a foundry are often started m the core shop. .
The question as to whether a mold should be m~de in green or dry sand is primarily one of cost and ~msh, the amount of machinery to be done on the finished casting, and the type of molder available for the work.
General Principle in Molding The general principle in molding is that the pattern
of the article to be cast is embedded in the sand, producing its shape in the moldtng material. When the pattern is removed, the cavity is filled with. molten metal. All the appliances and methods employed m the foundry are focused on this general priq,ciple.
The Flask or Box Molding boxes or flasks may be built up in sections to
fit over each other, and to fasten securely together for the purposes of confining and strengthening the sand mold.
FIG. 3. Snap Flask Weight.
From Wendt's Foundry Work.
While sometimes made of wood, molding boxes are commonly made of iron, which is capable of standing greater stress, and does not warp as does wood. Pat-
Foundry Practice 5
terns may be molded in t wo boxes, an upper, often called the cope, and a lower box, known as the drag.
If there are intermediate parts to the flask, they are called cheeks. Wooden flasks should be made of substantial material, as they are liable t o burning, and in a short time, if too light, will be completely burned away at the joint, and run-outs of the mold will be frequent.
Flasks are fi tted with pins and sockets, holding the parts firmly together.
For small castings the molds are rammed up on benches or projecting brackets. Such work is called bench work, and the fl asks employed are usually of the type known as snap flasks. Figure 1, page 2, shows a snap flask, hinged on one corner, w ith catches on the diagonal corner. In a flask of this type any number of molds may be cast.
Mold Board A smooth, straight board, called the mold board, the
size of the outside dimensions of the flask, should be a part of every flask. Rough boards or bottom boards of same size should be provided, one for each mold that will be up in a day.
Boards fo r snap work are made of f8 to 1-inch stuff, and should have two stiff cleats, t o hold them straight.
Wooden flasks of necessity receive hard usage in the shop, and grow weaker w ith each use. They burn, more or less, each heat , and receive rough usage when the mold is shaken out. If stored, they are subjected t o the disintegrating forces of mud and weather. It is therefore an economy to build w ooden flasks of heavy material. .
In drags, which may r equir e lift ing and moving, when the pattern is made in them, bars for lifting a r e made w ith thin, flat sides along the plane of the lengt h of the box; while in the cope, w hich may have to be lift ed off the pattern and turned over, the bars are placed edgewise in the patern-box, or flask, the flat side of the bar being almost the depth of the box, with the inside edge narrower than the outside. Such an arrangement furnishes great support for the sand, enabling it t o w ithstand the extra handling.
TOOLS l
) :
F G H J
©==· M:==io•-•·
FIG. 4.
Foundry Practice 7
Molding Tools Figure 4, from Wendt's Foundry Work, shows many
of the tools used by the molder. For cutting and handling loose sand the molder uses
a shovel, A, with flat blade, so that the sand can slide off the side of the shovel as well as off the end. This is often convenient when shovelling sand into bench molds.
The foundry sieve or riddle, E, is used to break up and remove lumps, shot iron, nails, etc., from the sand placed next the pattern or joint. Sieves should have oak rims with brass or galvanized iron wire cloth.
Rammers, B and C, are used for evenly and quickly packing the sand in the flask. One end is in the shape of a dull wedge, called the keen edge, the other is round and flat, called the butt end. Fig. 4, C, shows the type of rammer used on bench work. Fig. 4, B , is a floor rammer, for use in floor casting.
A pneumatic rammer is sometimes used to butt off large flasks, and for ramming loam molds in pits in shops equipped with compressed air.
D of Fig. 4 shows the bellows of standard type. K, the brush used by the majority of foundries. The swab, L, is used to moisten the sand around patterns before they are drawn. · F is a straightedge used to cut the sand level with the flask , after the mold is rammed. I is a vent wire. G is a draw-spike, and H a ra,pping ba;r, whose uses are detailed later. The wood screw , M, is used for drawing patterns from the mold. The draw -screw, J, is used when the pattern maker has put threaded draw holes in the pattern.
Sixty or more combinations of shapes. of molder's tools are on the market, designed for shaping and slicking the joint surface of a mold, and finishing the faces of the mold itself. These include trowels, slicks, lifters, swabs, draw-sticks, vent-wires or rods, clamps and wedges.
Trowels are used for shaping and smoothing the larger surface of the mold. Slickers, designated by the shape of the blade (heart and leaf, leaf and spoon, spoon and lead, heart and square, etc.), are used for repairing and slicking small surfaces.
8
_ID
Merit Badge Examinations
c FIG. 5.
Molder's Tools.
A, Finishing Trowel; B, Square Trowel; C, Lifter.
D, Double-end Slick and Spoon; E, Combination Slick and Lifter;
F,, Gate-cutter. Frnm Wendt's Foundry Work.
' Lifters are used to clean and finish the bottom and
sides of deep, narrow openings. Before drawing a pattern from a mold, a swab is used
to moisten the edges of the sand. A swab must be used with great care, lest the too free use of water around a mold result in blow holes. By fastening a piece of sponge to the end of a goose quill, or even a pointed hardwood stick, the water in the sponge can be made to trickle off the end of the quill or stick, drop by drop, thus moistening the sand gradually, with no danger of over-wetting.
Vent wires are used to pierce small holes through the sand, connecting the mold cavity with the outside air. A knitting needle with a short hardwood handle or knob at one end, forms a convenient vent rod for bench work. The smaller the needle, the better, provided it does not bend when used.
Draw sticks are used to rap and draw patterns from the sand. They are of many designs. Sometimes a metal plate (called a rapping plate), with threaded holes is let into the pattern, and a draw stick with machin~ screw thread is used, the same being screwed into the rapping plate, and thus by steady pull, withdrawing the pattern.
Foundry Practice 9
Brief Discussion of Requirements for the Merit Badge in Foundry Practice
1. (a) Make· a Freehand Working Drawing of a Flask Used For Bench Molding in the Foundry.
A working drawing is an instruction to the maker of the article draw n, and its primary function is t o carry detailed information.
Since drawing is included in the curriculum of all schools, it is safe to assume t hat the average scout has had sufficient training in di-a wing to fulfill this requirement.
Flasks are sets of open frames in which the molding sand is confined in making a casting. A flask consists of two or more boxes, held together with pins and sockets. The flasks for small moldings are rammed up on benches or brackets. Such work is called bench work. The flask, then, of which you are required to make a freehand working drawing, is a very simple box-like structure, of which Fig. 1 is typical.
A visit to a foundry, or to the founding branch of a technical school, should give t he scout access to a number of flasks used in bench work, from which he can determine the type he will use in his working drawing.
Remember that a working drawing fails in its mission unless it is perfectly clear. The message itself should be clear, and the lines presenting it should be clean-cut and distinct. Moreover, the drawing should be neat in appearance. A slovenly drawing ' is likely to reflect careless or slovenly thinking . Make the drawing workmanlike, accurate, distinct, one in which you can take pride.
( b) Describe Same Flask.
Exposition is far more difficult for the young w riter than narration. Be sure that your description of the
- flask is so complete and detailed that one reading it can visualize the flask. Thi.s quest ion is not as simple as it at first seems. Give pa,ipstaking thought to your
IO Merit Badge Examinations
answer, which should be simple and direct, but should cover all details. r · 2. (a) Show by Section Sketch a Mold' of a Plate 12" L ong,
6" Wide, 1" Thick, With Gate and Vents. This is a very simple problem, for a plate 12x6xl inches
involves bench work and no difficult manipulation. The size of the plate suggests that the time of cooling is sufficiently long to require venting, that is providing channels for the escape of gas and steam. Vent wires , used to pierce small holes through the sand connecting · the mold cavity with the outside air, will give adequate channels for the escape of gases. These will show in your drawing.
Gating is the term applied to the method of forming openings and channels in the sand by which liquid metal may enter the mold cavity. There are practically three parts to all gates-the pouring basin, the runner, and the gate. The pouring basin is shaped by hand on top of the cope. T he runner is formed by a wooden gate plug, and connects the pouring b;i,sin with the gate. The gate proper is cut w ith a gate cutter, and gives immediate access to the hollow mold. It should be smaller than the runner or the pouring basin, so that when pouring, the runner and basin may be quickly flooded; also that when cold the gate may be easily broken from the casting and lessen the trouble of cleaning.
FIG. 6. Mold Gated with Common Gate.
A, is the sprue made with a funnel shape at the top; B , is the gate cut in the drag, and C, is the casing.
From Wendt's Foundry Practice.
Foundry Practice
FIG. 7. Mold Gated With Pouring Basin.
The basin is shown at A, the sprue at B, and the casting at C. N ote that the basin is lower at D than at E . The m etal should be poured into th·e basiu slowly at D unitl it beains to run over at E into the sprue, when° the basin should be filled as quickly as possible.
From Vfendt's F oundry Work.
FIG. 8. l\fold Gated with Skimming Gate.
II
The skimming gate is made by setting the sprue, A , . and the skimmer, B in the cope and connecting them by the channel, C, after the cope ts lifted off. T he channel should be made a little larger than t he. gate, .D. The metal must be poured into the sprue fast et~ough to force it to nse to the top of the s)<:immer, and the sprue and skimmer must be kept full
thrr1ughout the pourini.rom Wendt's Foundry ' i\Tork.
With t hese points clearly in mind, a draw ing. showing a section of a flask with the casting, as specified, and the vents and gate, should not be beyond t he power of execution of any scout.
12 Merit Badge Examinations
( b) Construct The Mold. Before constructing the mold, read all that has been
said of molding sand on pp. 22-28 of this pamphlet. Select a flask large enough to hold the pattern and
have at least 2 inches clear of the flask all around the pattern. See that the flask is strong enough to carry the sand without racking, and that the pins fit. Have the necessary tools at hand, such as sieve, rammer, slicks , etc. Examine the pattern of the plate to be molded, and note where the parting line runs . The joint is that part of the mold forming the surface between the parts of the flask. Where the joint touches the pattern, it must be made to correspond with the parting line of the pattern.
The joi:-it, in this case, is a flat surface and is formed entirely by the mold board.
FIG. 9. Pattern and Drag Placed on Molding Board.
From Wendt's Foundry Work.
Place a smooth mold board upon the bench or brackets. Place the drag (lower portion of the flask) upon this, with sockets down. Set pattern a little to one side of center, to allow for runner. Sift sand over this about 1,0 inches deep. Tuck sand firmly around the pattern and edges of flask, using hands for packing. Fill the drag level full with molding sand. With the peen end
FIG. 10. Drag Filled Heaping Full of Molding Sand,
From Wendi's Foundry Work.
of the rammer slanted in the direction of the blows, ram first around the sides of the flask to insure the sand
- ......
Foundry Practice 13
hanging in well. Next, carefully direct the rammer around the pattern. This work must be very carefully done. Shifting the rammer to a vertical position, ram back and forth across the flask, taking care not to ram too hard, nor to strike the pattern. Then fill the drag heaping full of sand. Pack this well and smoothly until the drag is completely filled . With a straight edge level off to the bottom of the flask. Now cover the bottom of the mold with loose sand to the depth of y,i. inch. On this loose sand press the bottom board, rubbing it slightly back and forth to make it set well. With a hand at each end, firmly grip the bottom board to the mold and roll it over. Remove the mold board and slip over the joint surface with a trowel. Dust parting sand
FIG. 11. Face Plate Drag Ready for the Cope.
From Wendt's Foundry Work.
over this joint, but blow it carefully off the exposed part of the pattern. Set the wooden runner or gate plug about 2 inches from the pattern.
· Set the cope on the drag, being careful if it is a snap flask to see that the hinges of the cope and drag come at the same corner.
FIG. 12. Cope and Sprue Set in Making Face
Plate Mold. From Wendt's Foundry Work.
Sift a layer of sand, about 1,0 inches deep. Pack firmly with the fingers about the lower end of the run-
Merit Badge Examinations
ner and around the edges of the flask. Fill the cope and proceed with the ramming as before.
·Strike off the surplus sand, leaving a flat surface of sand. Vent the cope by driving in a vent wire, making it strike the pattern in several places.
Partly shape a pouring basin with a gate cutter before removing the runner. · .
Draw the runner, and finish the basin with a gate cutter, smoothing it up with the fingers. Moisten the edges with a swab and blow it out clean with bellows.
The cope should then be lifted off and any imperfections in the mold surface repaired with trowel or slicks.
Having finished the cope, moisten the sand about the edges of the pattern with a swab.
The removal of the pattern from the sand is a matter involving great care and delicacy of handling. A draw spike should be driven into the . center of the pattern, and this (the draw spike) should be lightly tapped, front, back and crosswise, w ith a mallet. H aving loosened t he pattern by this tapping, draw it carefully from the drag. If any break occurs, it should be repaired. Cut the gate, and smooth it down gently with the ·fingers. The mold should then be blown out clean with bellows. The mold should now be closed, and may be regarded as finished.
FIG. 13. F ace Plate Mold Closed.
From Vl' endt's Foundry Work.
3. Make a P erspective Sketch of a Pulley Pattern 611 in Diameter, 2" Face, Thie Center to be Cored' 2" by Use of Core Prints.
The diameter. of the pulley pattern 6", is the diameter from the top to the bottom 'of the pulley pattern. As this is shown in perspective in the working drawing, this
......
Foundry Practice
dimension, lengt hwise, w ill be g reater than the diam eter draw n a t right angles t o it through the center.
The opening shown to r epr esent the 2" core w ill also be shown as an oval, rather t ha n a s a circle (due to perspective draw ing ), and the diameter from t op to bot tom will be the 2" diameter, w hich, o f course, w ill be 011ethird of the diameter of the pulley.
By the "face" is meant the t hickness of t he pulley. This dimension is always somewhat grea t er than t he width of the belt it carries; e. g ., a pulley w it h 2" face would probably carry a belt l _0 11 wide.
The fact that the center is cored ·will be indicated on your drawing by cor e print. This w ill indicat e t o t he molder that he must make a slig ht indentation in th€ sand to accommodate t he core. W hen t he ca sting has cooled, the cor e is broken out, leaving the 2" hole as desired.
Be sure that your drawing is clear, clean, a nd legible. Be car eful t o let ter plainly and t o indica t e all dimensions.
The value of your dr awing w ill be dependen t upon the ease w ith which the w orkman w ho is to const rue:: the pulley pattern (see Requirement 4) can read his directions from the drawing. 4. Construct a TVood Pattern c.nd Core Box as P er S!~e teh
Outlined in Question 3 ; Use S hrinlwge R ule For the 111etal Used, Gray Iron, Bronze or Brass. Change JV!easureinents to Allow For Finish AU Over Casting aml Proper Draft for R ewwving P attern From Mould .
The making of this w ooden pattern wiil require ~he use of a lathe. It is presumed t ha t z.ny scol.1t a ttemptmg to qualify fo r t his merit badge, w ill doubtless have !1ad some experience in manual training, as pat tern makmg, while it is a distinct trade, is inseparable from fo undry practice, inasmuch as no casting can b e made w ithout a pattern, and this, the pattern, is made in the w oodworking shops, or "pattern rooms," as they a re. ca~led.
The shrink rule is a rule marked off 111 mches and divisions of inches like an ordinary rule, except that a shrink rule allows for the shr inkage of iron, which is Ys" to the foot. A foot shrink rule would therefore be actually 1' Ys" long, the marking of divisio.n~ ?eing ~he same as on an ordinary foot r ule, each d1v1s:on bemg
16 Merit Badge Examinations
augmented by its proportional part of the increase, _Ys". A casting made in a mold constructed by this. shrink
rule, will , when cooling, shrink to the true proportions. A core box is the box in which the core is formed.
The core is the body of sand used to form holes or openings through castings . The shape of the core in this instance is a cylinder 2" long and 2" in diameter.
By the draft is meant the shaping of sides of the pattern so that there· will be no resistance in withdrawing it from the mold. It can be readily seen that a slight slant in the outer edge, away from the center, would present a resistance which would make it q1:1ite impossi.ble to w ithdraw the pattern from the sand without causmg the walls of the mold to crumble. 5. Describe How a Cupola Operates.
One of the most important considerations in the foundry is that of melting the metal which is to be poured into molds. '
Heat for all melting is produced from the union of tvvo chemical elements, carbon and oxygen, carbon coming from the fuel, coal, coke, oil, or g'as, and oxygen coming from the air which is supplied in sufficient quantities by means of a blast.
The peculiar properties of the metal to be melted, and the degree of heat required for this purpose, determine th e design of the furnace, the kind of fuel used and the application of the blast.
· It is a far cry from the iron maker of early days, sitting cross-legged on his platform between his crude bellows of goat skins. with slits for air intakes, and nozzles of bamboo, which he works alternately, delivering pitifully small streams of air into the hole in the side of the clay bank, which is his furnace and from which. after hours of patient labor, his effort is rewarded by a few pounds of iron, and the modern blast furnace, with its towering height of 100 feet, its four huge heating stoves, the enormous blast engines which each minute deliver to the furnace 50.000 cubic feet of blast, and the whole array of dust arresters, gas ·washers, and automatic ore and coke handling machinery, which are essential to this King of modern metallurgical devices .
Insignificad, indeed, is the output of the ancient fur-
Foundry Practice 17
nace when compared with the daily yield of 500 tons of the modern blast furnace !
Foundry iron is melted in direct contact with the fuel in a cupola furnace. The name comes from the resemblance of this type of furnace to the cupola, which, about 1850, was very commonly placed on top of dwelling places. .
There are many different cupolas on the market which vary only in details of design. A typical cupola !s a straicrht shaft furnace , open at the top and bottom, !med with 0fire -brick, provided with a door at about the middle of its height through which the charge is introduced, and with tuyeres near the bottom through which the air is blown to consume the fuel which is charged to melt the iron.
The opening at the bottom is closed by hinged iron doors which are dropped at the end of the day's run to permit the unconsumed fuel and residue· of iron in the cupola to fall out and be removed.
The molten iron is drawn off through a hole at the bottom, and slag is removed through a hole in the opposite side, and at a slightly higher level than the iron tap hole.
The wind'bo:r, communicating with the tuyeres, encircles the cupola . near its base. Air is delivered to the windbox by a fan blower or a pressure blower, whence it finds its way through the tuyeres into the cupola.
The cupola should have a blast gauge attached to the wind-box to measure the pressure of air which ente.rs the tuyeres; this pressure should be sufficient to force the air into the middle of the cupola to insure complete combustion. Figure 14. shows that type of furnace.
The bottom is supported on four cast-i ron legs, some 3,% feet above a solid foundation .
The bottom opening may be closed by cast-iron doors, which swing into position, and are held in place by a rod or spud wedged between them and the floor. These doors, protected by a sand bed, support the charge during the heat, and when all the iron has been melted, are opened to "drop" it out of the furnace. The supporting legs curve outward, and the doors are hinged as far back as possible, to protect them from the heat of this "drop."
Char'11m; ]] Door
/lpproximofe Levels Iron
CoKe Iron
CoKe Iron
Cof(p .
First Char:;e ..
Bed
FIG. 14.
Scaffold ;. ,
I 8oiler Plate
Fire8ncK
Section Through Cupola Furnace. From F oundry Work by William C. Stimpson.
Courtesy of the American School.
Foundry Practice 19
At F is seen the wind-box, encircling the cupola, and communicating with the openings through w hich t he air is blown. T hese are called tuyeres, and are shown as H and J in the figure:
Several feet from the bottom there is a door in the side of ~he cupola called the charging door and marked D on the figure. Through this door the stock is charged into the furnace. In practice this door is usually at the level of the second floor of the foundry, or a platform is built around it.
At G is the blast-pipe, connecting the fan or blower w ith the wind-box. At C is the breast built a round the tap-hole T through which iron is removed from the cupola, being drawn off through a spout. This spout, protected by a fire sand mixture, projects in front of the breast and guides the metal into the ladles . T he bteast opening, at w hich place the fire is lighted, is at one side, level with the bottom. The height of the tuyeres above the bed-plate varies according to the class of work done in the foundry. The number of rows of t uyeres also ranges from one to three. They direct t he blast int o the fuel, increasing the heat sufficiently to melt the charge. The advantage of using t w o or more rows of tuyeres is that gases may be distilled from the fuel and escape without coming in contact w ith air blow n through the lower row; they must, how ever , pass t hrough air blown through the upper tuyeres, and thus become completely consumed. T he slag-hole and spout are shown at W. Cleaning door s are built on either side. The double row of tuyeres, therefore, reduces t he cost of furnace operation, and increases quick melting, inasmuch as no fuel is lost. Moreover, when running small heats, the upper row of tuyeres may be shut off by means of a damper. Or if the melt ing is taking place too rapidly, the blast may be diminished w ith consequent heat reduction, by shutting off the upper tuyeres, and the use of a damper in the blast pipe. Thus the melting rate of a cupola is always under control of the melter. ·
A contrivance is also employed by which, when the iron runs too high in the basin before tapping, it may be drawn off through a spout into the wind-box, where its
i
I 1
I
20 Merit Badge Examinations
heat will melt a lead plug, and it will fall to the floor thus giving warning that the cupola should be tapped.
The following routine must be pursued each time a heat is run off in the cupola : . Dump from the last heat must be cleaned away.
Lumps of slag collected about the lower part of the cupola walls must be chipped out by hand with a special hand-pick. A mixture of fire sand and fire clay, in the proportions of 1 to 4, wet with clay wash to the consistency of flour paste, is daubed about, filling the breaks in the lining made by picking out the slag. The greater part of the daubing will be required from the bottom to the level of the melting zone.
The bottom doors being swung up and closed by a prop (generally of gas pipe), the doors are covered with a layer of gangway sand or fine cinders, about an inch in thickness . Burnt sand, tempered about the same as for molds, is rammed evenly all over the bottom, and the bottom is built higher on the sides and back so that metal will flow towards the spout. The pitch varies with size of the cupola, 1 inch to the .. foot being the fall for cupolas of 24 to 30 inches inside lining.
Just inside the breast the fire is laid, with shavings and fine kindling, then larger kindling until there is centainty that a layer of coke sufficient to form the bed will be ignited.
When the fuel is thoroughly lighted, more coke is added to level up the bed, and the first ch.arge of iron is put on. Above this alternate charges of fuel and iron are placed to the level of the charging door. ~ ba~ of .iron about Ys inch round is laid in the spout,
proJectmg m through the breast opening. The breast around the bar is filled in with a strong loamy molding sand rammed hard.
The tap hole is left open when the blast is put on, but when the metal begins to run freely, is closed with bott clay, a mixture containing about 3i sawdust to make it more fragile when tapp·ed. The bott clay, made up in small balls, is applied by a bott stick, onto whose end it is shaped.
When sufficient molten metal has collected to fill the first ladle, the tap hole is opened by means of a tapping
Foundry Practice 2!
bar. W hen all the iron has been melted, the supporting bar is pulled away, and the bottom doors dropped, dumping the slag and refuse. This is wet down with a hose to deaden the heat, and left over night to cool.
The vessel receiving the molten metal is called a ladle . These are of various types and sizes, varying from 30 pounds to twenty tons capacity, and named according to the method of carrying them as hand ladles, bull ladles, and crane or trolley ladles.
Hand ladles are made of cast-iron or pressed steel ; the larger ladles are made of boiler plate.
The molten iron is poured from the top of the ladle which is therefore 1provided with lips. To protect them from burning through ladles are lined ; those up .to a ton capacity are lined w ith the daubing m_ixture used in the cupola. This is done by hand, a thick clay w ash being used, which is pressed in hard with the hands and rubbed smooth on the inside.
Larger ladles are lined with fire brick of thickness proportioned to their size, and then daubed on the inside with clay mixture similar to cupola lining. This lining must be thoroughly dried before using. For smaller ladles a ladle drying stove is provided, similar to a shallow core oven. Wood fires are built inside of larger ladles to dry them out.
Breaks in the ladle lining are daily repaired to preserve the lining as long as possible. 6. (a) Describe a Process For Cleaning One of the Above
Castings When Removed From Mold. When the casting has sufficiently solidified in the mold,
the flask is removed, leaving the casting in the sand. For light bench work and snap flask work the mold is lifted bodily and the sand dumped on the pile. The bottom boards are piled in one place and the cores in another for the next day's work. When all castings have been removed from the sand the gates are broken and thrown in a pile to one side. They (the gates) are now "scrap" iron and will be used in the next pouring.
When the casting has sufficiently cooled, it is sent to the cleaning room. Here castings are dumped into metal barrels; called rattlers , that are revolved until the sand and dirt have been jarred from the castings.
22 Merit Badge Examinations
E3:ch barrel should be packed as full as possible, with several shovelsful of gates and shot iron thrown in with the castings. The cleaning is accomplished in from 20 to 30 minutes, by the scouring action of castings, scrap, etc., rubbing against one another.
Castings of a similar character as to form and weight sh.ould be rattled together, otherwise the lighter castings will be broken by the heavier. When they are removed from the barrel, the casting should show a smooth clean surface, of an even gray color.
From the rattlers castings go to the grinding room where slight roughness is removed on the emery wheel '.
FIG. 15. Tumbling Mill or Rattler.
From Wendt's Foundry Work.
7. Describe The Properties in Sand That Are Best Suited For Foundry Use and Tell How to Prepare Sand For Use.
The chief material in which the molder works is sand. The essential property of the molder's sand should be its capability of binding together, or retaining the shape into which it has been molded, while at the same time re-11'.ai:iing sufficiently porous to allow of the escape of the air m the mold, and of the gases generated by the action of the hot metal upon it and its binding constituents. Moreover, it must be sufficiently refractory to withstand the very high temperatures to which it is subjected without risk of fusing, and be able to give a smo-oth and finished appearance to the surface of the casting.
All sands are formed by the breaking up of rocks due to the action of natural forces, frost, wind, rain and the action of water. '
Foundry Practice 23
F ragments of rock on a mountain side are broken off by action of frost, and are w ashed into mountain streams through the action of rainfall. Here they are ground one against another, and carried by · the stream into the current of the mightier river. Ground into finer and finer particles by the turbulent current, they are finally deposited as sand in shallows and along the recessed shores where the current is less swift.
The finer sand and the clay have a tendency to settle lower and lower down in the bed, so that we often find a top soil formed over them so long have they remained deposited. Removing the top soil we find first gravel or coarse sand, then finer sand, and finally clay ..
But rocks are complex in their composition, and as sand is pulverized rock, sands vary greatly in their characteristics, and are not all suited to every grade of work. Frequently a composite made by mixing two or more sands from different localities will give a desired grade and quality of molding sands when no single sand in the mixture is suitable. '
The principal requirements of good m.olding sand are the following:
Resistance to fusion. Molding sand should, first of all, be refractory, that is, have the power to withstand the heat of molten metal.
Bond: An essential property of the molder's sand should be its capability of bonding together, or retaining the shape into which it has been molded. Because of its refractoriness and the bonding properties which it possesses, a fine molding sand will withstand the high temperatures of the foundry; but sand molding has one serious defect, which is, that after a single casting has been made from a mold (often involving long and arduous labor and careful preparation, probably on the part of several men), that mold has to be completely destroyed to retrieve the casting, and if a duplicate of the casting is to be made, another mold, involving a repetition of the labor, must be prepared.
Many attempts have been made to construct molds which could be used successively in the casting of duplicate forms. The greatest degree of success in these attempts has been attained in the use of metal molds.
Merit Badge Examinations
But to return to the essential qualitie? of molding sand : Permeability: It must be permeable to permit the escape of ga ses from the mold while filling with metal. The pores in the mold are filled with air, and this , when heated ·during the pouring of the metal, expands. The sand must have sufficient cohesion or bond to withstand the pressure due to this expansion, but it must also have sufficient permeability to permit the escape of the containe.d air, and of the gases which are generated in the pourmg.
The greater the ease with which the air and gases escape, the less need is there for a strong bond.
In green sand (see p. SS) more or less water is contained in the mold, which, in casting, is converted into steam, and this must also escape. A molding sand must therefore have not only sufficient cohesion (bond) to hold the particles together, retainit).g the form of the mold during casting, but it must also have the necessary permeability to permit the escape of air, gases and steam.
Finally, a good molding sand must have an even grain. Sharp, angular grains have a greater pore space than rounded grains of the same size, indicating the difficulty in making angular grains pack well. Microscopic tests are necessary to determine whether sand will make a good casting, as such tests reveal the shape of the grains, whether they are flattened, rounded or angular, which in turn determines how closely the mold can be rammed and still permit the gases generated in pouring to escape. A sharp, angular grain is necessary, for sand with this grain can be firmly rammed around the pattern, and yet give a porous and permeable mold.
· With a strong, open sand a poor molder will often make a better casting than will a good molder using a sand lacking in permeability.
The two important chemical elements of molding sand are silica, which is the heat-resisting element, and alumina or clay, which gives the bond.
If heavy castings are to he made a sand containing more silica and less clay (bond) is required to resist fusion, as the sand must withstand a high degree of heat for a long period. The refractoriness (heat-resisting property) of sand depends on the amount of silica
Foundry Practice 25
it contains, but the bond decreases as the silica increases. When the sand available for large castings is found to be too close in texture (its grains being flat or rounded, and therefore giving the sand less porosity) to have sufficient permeability and refractoriness , silica sand or ground silica rock is sometimes added to open up the molding sand.
As sand becomes coarser, its bonding properties, which give cohesion, decrease and the silica conte.nt, which aids in resisting fusion, increases . Many castmgs made in green sand remain in a liquid state for a considerable time after pouring. They may also require churning (pumping or feeding with hot iron) , during which period the sand is constantly absorbing heat from the casting. The resistance to fusion, as well as the cohesiveness, must be great to prevent crumbling under the intense heat .
Molding sand, as it comes from the pit where it is mined, contains a certain amount of animal or vegetable life. To get rid of this the sand must be burned.
Palmer, in his Foundry Practice, cites an instance of what may happen in using an unburned sand.
A large mold made of new sand remained unpoured for a number of days after finishing. On being opened prior to pouring, it was found that a number of plants were sprouting from the surface of the mold. Much time was lost, and a good deal of expense incurred in going over the surface of the mold to repair the damage caused.
Besides silica and clay, the other elements found in molding sands are oxide of iron, oxide of lime, lime carbonate, soda potash, combined water, etc.
Silica alone is a fire-resisting element, but it has no bond. Under heat silica combines and fuses with the other elements, forming silicates. These silicates melt at a much lower temperature than does free silica. In sands carrying much limestone within their make-up, or those containing much oxide of iron, soda potash, etc., the molten iron will "burn in" more, making it more difficult to clean the castings. Limestone combinations also go to pieces under heat, tending to make the sand crumble, and resulting in dirty castings.
26 Merit Badge Examinations
Fi1:e ~and is used in the daubing mixture with which the ms1de of cupolas and ladles is overlaid. It must have h.e~t-resisting powe:· of a high degree, and contain the m1mmum of those mgredients that tend to make it fuse or melt.
Light n:olding sand is used for castings such as stove plate, which may have very finely carved detail on their surface, but are thin. To bring out this detail the sand must be very fine, and it must be very strong (high in clay), so that the mold will retain every detail as the m~tal rushes in.. As castings of this nature cool very qmckly, there will be very little gas to come off through the sand after the initial escape 0 £ air and steam.
FIG. 16. , Molds Weighted for P'ou.ring.
From Palmer s Foundry Practice, by Permission of John Wiley's Sons.
M ediu111, sand is used for bench work and light floor work. The bond should be strong to preserve the shape
- of the mold, but the tenden~y of the larger proportion of clay to .choke the vent, 1s offset by the larger size of the gram .. The metal will remain hot in the mold for . a longe.r time, . and gases will be forming during the entire coolmg penod.
Heavy sand. This i~ us~d· f~~ the largest iron castings. The sand must be high m silica and the grain coarse, because the heat of the molten metal must be resisted by the sand, and gases must be carried off throtwh the sand for a long period following the pouring.0 The amount of bond, or clay, must be small or it will cause the sand to cake, closing the vents, and preventing the
Foundry Practice 27
free passage of these gases. The lack of bond is compensated by the use of gaggers, nail~, etc. , to hold the mold during the pouring and coolmg process. !he coarse grain is rendered smooth on the surface by slick-
ing. . Core sand. This sand must be qmte refractory, but
must have very little clay bond. The bond v.:oul~ ca~se the sand to cake, choking the vent, and makmg. 1t difficult of removal from the ca.vity when cleanmg the casting.
Sands having practically no clay are called free sands . Of these the two kinds in use are river sands and beach sands. The little, sharp grains of river sand _interlock one with another, and make a strong core. River sand is therefore much used in large core work. Beach sand, whose little rounded particles are .worn si:nooth by. the action of the waves, has the ment of bemg relatively inexpensive and in coast sections is much used, but only for small cores.
Parting sands, or parting dusts, must be absolutely free from bon.d. They are used to throw on the damp surface of molds which must separate one from another. They prevent these surfaces , formed of high bond sands , from sticking together.
Molding sand, after being used a certain length. of time, loses its bond or cohesion. Every time a castmg is removed from ;;, mold, a certain amount c;if sand adheres to it, and is thereby lost. New sand 1s added to the sand heap, not only to make up this loss , but also to renew the bond, or cohesive quality . The color of new molding sand varies from yellow, or reddish y~llow, to deep reddish brown, due to the presence of oxide of iron. Molding sand which has been used, gradually becomes very black as a result of the burnii;ig into the sand of the sea coal facing . As the sandpile becomes black in color, it should be tested, and if found lacking in strength (due to the burning out of the clay), the sand should be removed. A mold made of sand of low strenrrth is liable to have the face washed from it by the i~fl.owing iron. Moreover, in closing the mold a portion of the sand is liable to drop.
28 Merit Badge Examinations
Foundry men have many ways of testing the physical property of sand. A foundry man will take a handful o f tempered sand, squeezing it in his hand into an elongated mass. He then suspends this mass, holding it between thumb and finger. If it breaks off of its own weight, it is not considered a strong sand. If, however, it hangs together, there may be an excessive amount of clay present. To test this , a small portion is wet and rubbed between the thumb and forefinger, the amount of clay present being judged from the stickiness of the sand as shown in this operation.
Preparation of Sand for Molding When the fl.asks which held the previous day's casting
~ave been shaken out and the castings removed, the sand is wet down. The molder or his helper do this with a pail o~ w.ater! throwing the pail around in a circular path and tlppn:g 1t so that the water will fly over the edge on one side and form a thin sheet, covering quite an area .. When t~1e sand is sufficiently damp, new molding sand 1s added 1£ the sand used oi1' the previous day was found to have insufficient strength. The new sand is spread over the entire surface. It is then "cut over" with the shovel. As each shovelful of sand is thrown a twist is given to the shovel to spread the sand as mu'ch as possible. Lumps are broken up with the fl.at, or under part of the shovel. Dry portions are wet care being taken not to make the sand too wet, as an ~xcess of moisture causes the metal in the mold to bubble or "kick," wher~as sand that is too dry will crumble, when the pattern 1s drawn.
Only an experienced molder can determine by the sense of touch a properly tempered sand.
When sand has remained in the fl.ask some time after the mold has been poured, it may bake hard in the fl.ask. When the mold is shaken out, the sand will be found to be lumpy. These lumps must be. thoroughly broken up bef?re wetting, as otherwise they will not absorb the moisture, and while sand is being riddled over the pattern, a small shower of dry sand will fall into the mold, and will fail to cohere to the tempered sand. The result will be a rough-a broken casting. The more thoroughy
Foundry Practice
sand is tempered and cut over. the more easily it will be worked by the molder. 8. Tell what Important Safety Precautions Sho1tld be
Taken to Protect the /!Vorkers in a Foundry- B )' the Employer?-By the Employee?
The greatest enemy to sa~ety is c~1~elessness . Employers may make every possible pr~w1s10n f<?r ~a~ety of the employed, but if there is an attitude of 111d1fterer~ce on the part of the employee, the safeguards may be in-
effective. The sense of caution, then, must be recognized as the
chief factor in accident prevention. In the development of this attitude of personal caution, the e.n~pl?yer , by his initiative, energy and intelligent superv1s10n, counts most in the education of his workmen.
It is not practicable in a pamphlet of this s?rt to take up in detail the matter o~ safety m~thods 111 foun~ry practice. Foundry work 1s necessarily an occupat10n involving special hazard, and to cover th:e gro.und completely would require a very lengthy d,1scuss10n.. The scout is therefore referred to Alexanders Safety 111 the Foundry, where this subject is fully and interestingly discussed and is also urged to consult foundry workers, iron-masters, and foundry foremen or superintendents. Information gained at first hand will be most serviceable.
The followina suggestions merely touch upon the subject, and should not be accepted as ~overing the matter adequately. Concerning the precaut10ns to be ~bserved by the employer, the following are tl~e most obv10us :
Danger signals should be placed 111 any place :vhere unusual danger exists, or where unusual danger is not apparent. .
Orderly arrangement on the foundrY: floor , wide, clear aisle space reduces the hazard of h~ndhng hot metal.
Safety and health of employees 1s promoted by plenty of good air and sunshine.. ~he daJ'.ligh.t shop and daylight foundry should be the ann. This will mean _frequent window cleanina as the windows are very qmckly obscured by the ~1;1oke, dust and _fumes in tl:e foundry . Where artificial light is a necessity, every effort sho:1ld be made to keep the window glass clear, and thus give the maximum of direct light.
30 Merit Badge Examinations
Cranes and hoisting apparatus should be frequently inspected, and equipped with every safety device known, and finally, they should be in charge of a craneman of expert judgment. The handling of such machinery should never be entrusted to an inexpert employe e.
All tools should be kept in perfect condition. The clanger of using defective tools should be frequently impressed upon the workmen. . In handling many departments of foundry work there 1s a safe and unsafe ·way, and it should be a part of the duty of every foreman to instruct employees in the safe way, and to insist upon its observance .
. Goggles for the protection of the eyes should be provided ~y ~h~ employer, and these should be so adjusted to the 111cl1v1clual that they can be worn without discomfort.
The following responsibilities devolve directly upon the employee: ·
First of all, he must cultivate the habit of caution. · Familiarity with a hazard too often breeds an attitude of indifference, and a willingness· to "take a chance."
Individual safety, and )n many cases the safety of others, demands the habit of caution on the part of each employee.
Safe clothing is essential to prevent accidents. The qt~es~ion. of safe clothing in the foundry means first the ehm111at10n as far as possible of thin, ragged, greasy, loose and baggy clothing, and worn-out or laced shoes.
Men should wear the one-piece suit where possible thus ~limina~ing much of the hazard from loose or ragged clothmg. Fire-proofed cluck suits will shed sparks and small spatters_ of metal, and will not burn readily. ·
Asbestos sUits can also be secured, and are sometimes necessary.
FIG. 17. Bull Ladle and Shank.
1'rom Wendt's Foundry Work.
'
Foundry Practice
Safety shoes (the Congress shoe, with thick sole~) should be worn, and leggings, of which there are several types which absolutely will prevent burns.
For workmen handling ladles or hot metals, also for welders and other operators, asbestos gloves, leg pz Gs and aprons should be donned. These may be uncomfortable and heavy, but it should be the responsibility of each workman in a foundry to reduce the accident hazard, by ~iwariably taking every possible precaution in dress, and 111 the careful execution of each detail of his hazardous work.
FIG. 18. Hand Ladle and Shank.
From Wendt's Foundry Work.
This brief discussion merely touches upon a few obvious points in this very large subject of foundrysafety. The scout is recommended to inform himself more fully, by reading, and by personal conference with foundry workers and officials.
THE EARLY HISTORY OF FOUNDING Looking back over history we see a period of many
thousands of years when primitive man lived in caves or other rude habitations and was entirely without the implements we now consider indispensable.
His weapons of offense and defense were clubs, wooden spears, topped perhaps with bone or shell, and hatchets of chipped stone, tied with thongs of hide into a split stick. With ingeniously devised snares and these crude weapons he secured game and fish for the support of his family.
32 Meri.t Badge Examinations
W hen grain began to supplement the fruit and wild game diet, it was milled by being crushed between two fl at stones, or ground in a stone mortar.
Scouts were not the first to kindle fire by friction. These skin-clad ancestors of ours secured the desired
.flame only after long and laborious twisting or rubbing together of two dry pieces of wood.
From the trunks of fallen trees, aft er liberal burning away of parts and with the help of his war hatchet, the caveman fashioned a craft which would float on water. This was doubtless after countless thousands had learned that a floating log would support his weight. A second step was doubtless the lashing together of several logs with leather thongs or tough withes, in the construction of a crude raft. But the raft was awkward, clumsy to manage, and altogether unsatisfactory as a craft for swift moving water. The canoe, or "dugout" marked a distinct advance in man's mastery of the water. This period was known as the Stone Age and iron and steel were unknown.
Copper has always been found,, in various parts of the world in the "native" or metallic form ; that is, w ithout the other elements which in combination w ith it make the ore.
FIG. 19. Primitive Forge.
Reproduced by Permission from Spring's Non-Technical Chats on Iron and Steel.
In the course of time man learned that this soft red metal could be pounded into thin edged implements more serviceable than his clumsy tools of wood and stone.
Foundry Practice 33
Scm-: of t~ese metal impl~ments were hard and had fairly good cuttmg edges. This was due to t he accidental or intentional presence of tin. Little did the man of this period (the Bronze Age) dream that the t w entieth century, on fi nding . his buried bronze implements w ould think his crude alloy so w onderful and talk re~erently of a "lost art of tempering copper."
Gold, w hich also occurs native, was known to our ancestor, pri1!1itive man .. T he melting point of gold is ~o low that it could easily be formed int o ornaments, ~dols and other articles for religious purposes. But durmg the t housands of years of t he "Stone Age" and durinomuch of the "Bronze Age," copper, bronze and gold wer~ the only. m~tals u.sed. Although the smiths developed _great skill .m cast~ng and modelling these metals, t hey knew ;iothmg of n on or st eel. Little did t hey dream that, rightly t reated, certain of the heavy red, yellow or black earths lying right a t their doors could g ive up to them the most useful of all metals, iron. . Unlike copper and gold, iron never occurs "free,' ' havmg too great a tendency to chemically combine with o~her .elemei:ts, . such, for. example, as the oxygen in the au, with which m most climates it so readily forms "iron rust."
Moreover, its melting point is high and so great a degree of heat and so much carbon are required for its "reduction" from the ore t hat during thousands of years it had never been produced.
But one day, by accident, and under the for tunate coincidence of r ich ore, high heat and an abundance of carbon. in. the form of charcoal from wood, a lump of metallic iron was formed underneath a pile of logs which had got afire and burned fiercely because of a high wind.
When pounded between t w o stones this metal proved to be superior t o anything yet known for spearhead or other weapon.
The art of ex~racting.iron from the ore spread slowly, but eventually it became more and more generally produc~d. Eyidences show that in Egypt , Chaldea, Borneo, India, Chma, etc., roughly similar processes and crude furnaces were used:
34 Merit Badge Examinations
T ubal-Cain is mentioned in the Bible as an "artificer in iron and brass," and a wedge of wrought iron was buried in the great pyramid of Cheops, probably as early as 3500 B. C. This wedge is now in the British Museum.
The Chinese made use of iron many centuries before the Christian Era, and the Assyrians used the metal on a r eally extensive scale.
At Delhi, in India, is still standing a pillar 22 feet high made up of several wrought iron sections cleverly welded together. It is supposed to have been erected about the 4th or 5th century B. C.
FIG. 20. Catelan F orge.
Reproduced lJy Permission from Spring's Non-Technical Chats on Iron and Steel.
T he earliest furnaces were crude things, being mainly heaps of wood and charcoal and iron ore on the crest of hills where high winds fanning the blaze gave the necessary heat.
Later, with the invention of crude bellows, smelting was done in small holes in the side of clay banks, charcoal being used as fuel.
Foundry Practice 35
The early Britons made iron in crude furnaces called "bloomaries" and there was little improvement up to the time of Elizabeth when strict laws were enacted to prevent the utter destruction of fo rests for the production • of charcoal.
The Catalan forge, named for Catalonia, north Spain, w here it originated, is the fo rerunner of our modern blast furnace. The Catalan and furnaces of a like nature, produced a variable kind of w hat we know as "wrought iron." Our modern "cast iron" did not appear until about the middle of the fourteenth century, when, with larger furnaces, an excess of char.coal, w ith greater heat and other favorable conditions, t he Germans found that they could make t he pasty metal absorb enough carbon to make it easily fusible.
Summarizing, iron ore is the metal iron in combination w ith the gas oxygen, which forms one-fifth of the air we breathe. Under the influence of intense heat the oxygen can be released by carbon. The result in the small, crude and inefficient furnaces of long ago was a small ball of crude iron, pasty and difficult to melt, but malleable when cold. This was "wrought iron."
When, however, much more carbon in the form of charcoal was present in the highly heated furnace, than was necessary simply to combine with the oxygen of the ore, the liberated iron greedily absorbed enough of the extra carbon to liquefy it. This liquid iron could be poured into molds and in that w ay made into various useful shapes. It became knovvn as "cast iron" because of this property.
It has been estimated that iron forms 5 per cent of the total substance of the earth, but it is very unevenly distributed. The amount of iron in rock varies from a minute trace up to 70 per cent of the whole rock. It is only when the percentage of iron is 25 or above that it can be profitably mined.
Iron does not occur as pure metal but in combination w ith other elements- oxygen, carbon, sulphur, etc.
Recent investigations show that the iron ore resources of the world are practically inexhaustible.
Russia and China have immense fields which have never been t horoughly investigated.
I I
Merit Badge Examinations
The most important deposits of non-phosphoric ores of Great Britain are the ores of Cumberland and Lancashire. Spain has the most important deposits of this ore in Europe.
In the United States the Lake Superior District supplies the principal non-phosphoric ores . . The enormous supply of this ore and its excellent quality account largely for the great development of the American iron and steel industries. Pittsburgh's great advantage as an iron and steel center has been due to its proximity to an extensive seam of bituminous coal and ore in adjacent counties and its location so near the Great Lakes, which provides cheap water transport ation for the Lake .Superior ores. The first iron works in Pittsburgh were established in 1790. The development of the Birmingham, Alabama, district is also of great importance.
We can have but a slight appreciation of the debt which civilization owes to iron, for practically everything with which we come in contact contains or has resulted from application of iron in some way or other. ·
Our cooking utensils and implements, the kitchen range, water and drainage pipes and furnaces and heating plants of our houses are largely of iron.
The steel frames of skyscrapers and bridges are largely of structural steel. The wood, brick, stone and cement are either shaped, molded or made by iron machinery. So with the conveyances by which we travel and most of the materials and articles which we wear, use and have constantly about us, would be impossible but for the machinery and tools necessary for their production.
The iron industry is sometimes spoken of as the barometer of a people's civilization. If all iron and iron products and their influence on the world were obliterated, it would set us back to a stone age civilization.
No matter how hard we try, few of us realize the immensity and importance of the iron and steel industry, with approximately 460 huge blast furnaces here, 5,000 cast and malleable iron foundries, about 1,000 Bessemer and open hearth steel and some 3,000 puddling furnaces and the many thousands of factories which are daily turning the products of these into pipe, wire, rails, plate
Foundry Practice 37
and the infinite var iety of ar t icles which are mighty factors in our civilization.
Yet wit h t hese furnaces and factories at our very door, the vast majority of persons ar e . obli:rious to their sig nificance and only annoyed by their noise and smok e.
THE HISTORY OF THE TRADE IN IRON R eprinted from Chapter X , I ron and Steel, Ch ristopher H ood, by permission
of I saac Pitman & Sons, London and New York.
Such a h istory begins with t he barter by the hunter, fresh from t he chase, of t he skins of his quarry fo r an iron t ool with w hich t o take off t he pelt , or by the t iller of the ground, of the g rain he had g rown for iron t o make a shoe for the point of his wooden ploughshare. There is no record of these early transactions, t here were no weekly iron market s, no quoted prices, no questions of "bull" or "bear " or "corners," or any of t he mischievous devices of modern commerce in those days. The necessities of the seller and the wealth of the buyer , who were also producer and consumer, fixed t he price to be paid and received. As t he production of iron increased and t he use of it ex t ended its value as a regular article of commerce would become more fixed. There seem t o be no records of pr ices until about 1638, when Dud Dudley sold iron made with pit coal at :£12 per ton, but t his is comparatively a modern date.
The earliest record of iron-making is the refer ence in Genesis to Tubal Cain as "An instructor of ever y artificer in brass and iron." He w as evidently the fir st expert in the treide which must , th~refore.' ha:re reached a very considerable degree of efficiency 111 his day. The records of the earliest civilization of the world, that of Egypt , contain ma ny refe rences to st eel and iron, and the metal was known to the Chaldeans, Babylonians and Assyrians. Early Biblical r eferences t o iron are numerous, one of the most curious being that of the iron bedstead of Og, the King of Bashan. Gol iath's spearhead weighed six hundred shekels of iron. J ob refers to the iron weapon, and the bow of steel and various tools of iron are referred to by David. Daniel wrote, "Iron breaketh in pieces and subdueth all things," and
M erit Badge E xaminations
Elisha made the iron axe to swim when it fell into the water, and the servant lamented because it was borrowed. The Medes and P er sians, and the natives of India, were acquainted ~ith the manufacture, and Wootz steel ha? been fam ous for ages and is yet preferred by the native swordmakers for the best weapons. The Arabs w ere early makers of fine steel and iron, as a lso were the Turks. It is recorded of Saladin that his sword was of such fine edge that he severed with it a down cushion thrown in t he air.
The Greeks were well acquainted with the manufacture of iron, and reference to it is made by H omer. In later times the ores of the Isle of Elba were worked by the Greeks. The Romans knew the value of iron but they were not great manufacturers of it thems~lves . The Celtibarians of Spain were famous makers of iron and ste~l , a~1d Di~dorus says their swords "cut through everythmg m their w ay that neither shield, helmet nor bone can withstand them." The ancient Britons knew ~h~ value of iron and used it for various purposes, and 1t 1s probable that they were acquainted with its manufacture from the ore, although it is quite possible that it was at first imported by the Phcenicians and other traders w ho came to the Cornish ports for t in. By the time of the first Roman invasion iron was made in the island and during the Roman occupation the manufacture of it was carried on in various parts of the country on a large scale. Enormous cinder beds in Monmouthshire and similar remains of iron smelting in other parts of the country in which Roman coins have been found testify to the Importance of the industry in those times'.
In Anglo-Saxon and Danish times the manufacture of iron was an important industry, the monks even en~agi.ng in it, and St. Dunstan is said to have had a forge 111 his bedroom. In Domesday Book, ironworks in Somerset, Hereford, Gloucester, Cheshire and Lincoln are referred to. Gloucester appears to have been a center of t.he trade, and its tribute to the King was paid in iron. Scnvenor says that from the Conquest to the end of the reign of King John iron and steel were imported from Germany, which probably indicates that industries
F oundry P ract ice 39
in England w ere flourishing and iron could not be made in suffic ient quantity. During the Crusades, the art of making chain armor was carried t o gr eat perfection in England, and the same perfection in making weapons had been r eached by the Saracens. In the r eign of Edward the Third a law was passed prohibiting the export of iron, whether made in the country or imported. The magistr ates were authorized t o regulate t he pri~e and to punish anyone who charged too much. In this reign cannon are fir st mentioned, and these w er e first made of iron. Scrivenor says t hat during the fourteenth and fi fteenth centuries iron and steel were imported from Germany, Prussia and other places, and iron from Spain, but as several improvements in the manufacture had taken place during this period in England laws were made towards the end of it against importing any of the articles of iron and steel w hich were manufactured in this country. The mak ers o f these articles in L ondon and ot her towns presented a petit ion t o Parliam ent in 1483 and an Act was passed prohibiting their importa-tion.
The t rade continued t o flourish in the Forest of Dean, Sussex, Somersetshire and Yorkshir e unt il 1558, when an Act w as passed prohibit ing the felling of timber fo r burning iron excepting in Sussex and part s of K ent and Surrey. T his prohibition w as ex tended in 1581 and 1585 so as to include all t imber "of the size of one foot at the stub," and prohibiting the erection of any new works in Surrey, K ent and Sussex, and here commences one of the g reat crises in t he t rade, viz., that due to t he change from charcoal t o pit coal fuel.
Up to this neriod the manufacture of raw iron was more perfectly underst ood on the Continent than in England. T he Germans and the Sw edes had developed the Blauofen and the Osmond furnace from the Cat alan forge and made better iron than was made in Engla.nd. But a ided by the earlier necessity to use hard coal owmg to the .denudation of the forests and by the invention of the steam engine, the English now took the lead and retained it unto our own time through many changes which resulted in a complet e revolution of the trade.
Merit Badge Examinations
Dud Dudley, in the seventeenth century, succeeded in making good iron by using pit and sea coal, but his invention was attacked by his rivals, his works were destroyed by floods, "to the great joy of many ironmasters," as he says. A staunch Royalist, he saw a patent for making iron with pit coal given by Cromwell to another-though he had the satisfaction of seeing it fail-and on the r estoration of Charles II he got no redress. So, in disaster and ruin, ended the first attempt to make iron with hard coal, and it was not until fifty year s lat er, in 1713, that Abraham Darby succeeded in using coke in the blast furnace . Dudley had estimated that in 1660, 300 furnaces were in blast , each making fifteen tons of iron per week during forty weeks in the year. This would give an output of 180,000 tons per annum. Owing to the scarcity of charcoal the number of furnaces in 1740 had fallen to fift y-nine, making only 17,350 tons per annum. Dudley's figures may not be very accurate, but it is evident that during these eighty years the trade passed through ·a very severe crisis in which the manufacture dwindled to very small dimen~ SIOnS.
The imports of iron were from Sweden, Russia and the American colonies. The policy of Great Britain with regard to her colonies at this time had the effect of stimulating imports of raw iron. The idea at the back of the policy was that t he colonies should supply us witb raw material, that \Ne should manufacture it into finished articles and return it to them in that form. · T o carry out this policy the importation of raw materials was. encouraged and the manufacture of finished goods in the colonies was prohibited. Scrivenor says: " In 1750 an Act, 23rd George II, was passed for encouraging the import of pig iron from the British Colonies in America. Every well-w isher to his country reflected with concern on the nature of the British trade with Sweden, from which country we imported more iron and steel than from all the other countries in Europe. For this article a great balance was paid in ready money, which the Swedes again expended in purchasing from the French and other mercantile states those necessaries
Foundry Practice
and superfluities with which they might have been as cheaply furnished by Breat Britain. In the meantime, our Colonies were restricted by severe dut ies from taking advantage of their ow n produce in exchanging their iron for such commodities as they were under the necessity of procuring from t heir Mother Count r y. This res triction was not only a g r ievance upon our own settlements, but also attended w ith manifest prejudice to the interests of Great Britain, annually drained of great sums, in favor of a nation fro m which we derived no advantage in return ; whereas, t he iron imported from America must of necessity come in exchange for our own manufactures. The Committee having appointed a day for taking this affair into consideration, carefully examined into the state of t he British commerce with Sweden, as w ell as into the accounts of iron imported from the plantations of America ; and a committee of the whole House having resolved that t he duties on American pig and bar iron should be repealed, a bill was brought in for that purpose: 'T hat pig iron, made in the British Colonies in America, may be imported duty free, and bar-iron into the port of London ; no bar -iron so imported to be carried coastwise, or to be landed at any other port, except for t he use of His Majesty's dockyards; and not to be carried beyond ten miles fro m London.' The Act, however, contained the following clause: 'That from and after t he 24th day of June, 1750, no mill or other engine for slitting or rolling of iron, or any plating forge, to work with a tilt -hammer , or any furnace for making steel shall be erected, or, after such erection, continued in any of H is Majesty's Colonies of America.' " Scrivenor goes on to show the results of this Act. The Governors of t he colonies were ordered to make a ret urn of the furnaces, etc., in t heir jur isdictions. This return show ed that there were four mills for slitting or rolling, one not in use, eleven plat ing forges with t ilting-hammers, t wo n ot in use, and five steel furnaces, one not in use. The ironmasters petitioned against the bill on t he ground t hat it would not lessen the import of Swedish iron, as that w as brought in for purposes for which the British and American
42 Merit Badge Examinations
were unsuitable, and that the colonies would be able with their cheap fuel to undersell the British manufacturer to the ruin of thousands of laborers, who would have to emigrate; also that if the British iron manufacturer had to depend on supplies from America, which would be liable to be captured by enemies or lost at sea, the trade would decay for want of materials. Against this view the ironmongers and smiths "of the flourishing town of Birmingham in Warwickshire," petitioned that the ironworks of Great Britain did not make l1alf enough material for the trade, and that if the colonies could supply the deficiency, the Swedish importation would cease "and considerable sums of money be saved to the nation." They pointed out what was evident, that the importation from America would be no different in its effect from importation from elsewhere. The bill passed, and in 1756 tlie Society of Merchant Adventurers of Bristol petitioned for bar-iron to be allowed to be imported into any port as well as London. This was urged because great qua-t1tities of bar-iron were being brought in from _Swede n, Russia, and other countries, and the curious old argument was again used that this was purchased with ready money, whereas if America sent it in it ·would be paid for by goods going out. The petition ·was opposed and a great controversy arose on what was considered a national affair. The opposers said that the fear of American imports had stopped the development of mining and iron-making, that the mines were inexhaustible and the growth of wood in coppices for iron-making utilized land which was otherwise of no value and improved pasture land by the shade it afforded, that the destruction of the coppices would reduce the bark available for tanning, that neither British nor American iron could stop the import from Sweden because the latter only could be made into steel; the import from America, therefore, could only interfere with the British. The promoters replied to all this, and ultimately the bill was passed with a clause repealing a previous enactment which prohibited the conversion of wood and coppice into pasture or tillage. A curious comment on all this agitation and fuss is the list
Foundry Practice 43
of exportations of iron from the American plantations, y; _ _ich is as follows :
Years . Tons. 1717 and 1718 together 7 1729 to 1735 average 2,111 1739 " 1748 " 2,423 1750 " 1755 3,305 1761 " 1776 4,045
b 1776 the imports of iron into Great Britain from Eussia were 34,000 tons, so that in spite of Acts of Parliament the "line of least resistance" was not deviated. There is little doubt that the irritation caused by these selfish trade regulations in the interests of British manufacturers and trade had much to do with the rebellion of the colonies.
In 1788 the quantity of iron made from coke was ,;8,200 tons, and from charcoal 13,100 tons . The effect on the trade of the substitution of coke for charcoal was to concentrate the manufact~re of pig iron in those parts where coal was found . Thus the iron trade of Sussex a:1d Kent disappeared and that of Staffordshire, South Wales and Yorkshire greatly increased. In Scotland the manufacture of iron from charcoal appears to have been 0:1 a very small scale, as the first furnace was erected in 1750 and in 1788 two furnaces .were blowing with charcoal and producing 1,400 tons a year. But the use of coke as fuel and the discovery in 1801 of the blackband seam of iron-stone laid the foundation upon which the great iron trade of Scotland has been built.
While this great change in the iron trade was taking place the invention of cast steel by Huntsman, in 1770, brought about an equally great change in steel, for by it the makers of fine Sheffield goods were provided with an ideal material for the manufacture of the finest cutlery. Huntsman was a watchmaker, who took up the question of improving the quality of steel. Whether he knew or learnt anything of the method of making W ootz steel or not it is impossible to say, but his invention was very much on the same lines as those by which steel had been produced for centuries in Eastern countries .
It is interesting to look back at this poi~t when Great
~ I I
I
44 Merit Badge Examinations
Britain became self-supplying in the matter of iron to the fluctuations in the imports in earlier years. As early as 1216 the home supply was so small that importations had to be made from the Continent, but the home production had so largely increased by 1483 that importations were forbidden, and late in the sixteenth century iron in the form of cannon was exported. This trade led to the complaint that Spain armed her ships with English cannon to fight against us, and consequently the export was forbidden. In the seventeenth century the civil war paralyzed the industry, and in the eighteenth the exhaustion of the forests led to recourse again being had to the Continent for supplies. But now came the change which put England in the leading posi-
FIG. 21. Beehive Ovens.
Reproduced by Permissior1 from Spring's Non-Technical Chats on Iron and Steel.
tion. While the Continent, with its large supplies of timber, continued to use charcoal fuel, the English works were driven to use coke. As experience with coke was gained it was found to be much cheaper than charcoal and the output of iron much greater. The abundant supply of coal and its proximity to the ore gave Great Britain a great advantage over the continental nations. Germany, her great competitor in modern times, up to the close of the Napoleonic wars in 1815, was constantly devastated by hostile armies which destroyed all industry for the time being, and America had not begun to develop her resources. · Great Britain, with peace within her own borders, took advantage of the opportunity to develop her iron industry which the
\
Foundry Practice 45
possess10n of coal and ir on-st one in vast quant ity enabled her to do. The lead which she was thus enabled to establish over her continental competitors was increased by t he early development of railw ays, and it was .not until 1890 that she had t o take second place owing to the growth of the t rade in the Unit~d States w ith its huge stores of iron ore, its great territory ancl large population. In 1903 Germany also pass_ed her owing t o the development of t he ~esseme.r basic steel process for w hich her ores are specially smtable.
We in Great Britain may regret that w e no longer Lo:d the blue ribbon for iron production, but it is .not a pos it ion w hich any action on our part coul~ po~s1bly have altered, and it is wisdom to accept the m evitable without getting angry. If w e could have treat ed the United States as t he American colonies w ere treated in the Georgian days and prohibited them from making any manufact ured iron, or setting up any plant for doinrr so then the American output of iron w ould have
b ' kept down, or if we could have suppressed t he T homas-Gilchrist process of steel-making, Germany could not possibly have become a great maker of steel, but under no circumstances was it possible to do ) either of these things. We cannot say t o the United States, "You shall not develop your minerals w ithout our permission"; nor to Germany, "We w ill not allow you t o use the Basic process," nor to nat ure, "You had no right to provide t hese countries w ith more iron ore than you gave to us ." Only very foo lish people would take up such a position, for it is cer tain that in the progress . of nations, all other things being equal, that country w ith the greatest natural resources will make t he lar_ge~t quantity of goods from natural products. Great Bnt~m can no more hope to rival America in the product10n of iron than t he Isle of Wight can hope t o rival England in the growth of corn, nor is it to be e.xl?ect~d th<1:t the 208,627 square miles and sixty-one million m habi·· tants of Germany will not require more iron than the 121,305 square miles and forty-four million inhabitants of Great Britain.
From 1836 to 1860 the British iron trade grew at a great rate, and the outpu t of pig iron reached 3,826,752
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tons in the latter year. Rail~ays a1'.d manufa.ctures of a'.l kinds called for an ever-mcreasmg quantity. The discovery of the main seam of Cleveland iron-stone led to the establishment of great works on the banks of the Tees, w hich were able not only t o supply the home market with pig iron, but to export it to the Continent, ivhere a great trade was built up. It is to be borne in mind that the whole of this pig iron in the home market was used for making malleable iron in the puddling furnace or for castings. The rail and plate trades were principally carried on in Staffordshire , on the North East coast and in South Wales. The most successful of these was that of Mr. Danks, which has been referred to. The succe ss of Bessemer's new process however put a stop to all attempts to improve the puddling fur~ nace, .which for the manufacture of rails and plates was practically abandoned. The transit from the puddling furnace to the Bessemer converter for the manufacture of ra.ils began in 1873 and was completed by about 1879, · and m the case of plates it lasted from about 1880 to 1890. In South Wales great distress was caused amoncr the workmen who were dismissed as the puddling fur~ naces were put out, no less than 734 out of 1,251 of these being extinguished between 1873 and 1880. In 1890 there were only eighty-three in operation, and in 1906 the number in North and South Wales together had dwindled to twenty.
The great development of the iron and steel trade in modern times began with the invention of the Bessemer process in 1855. Up to the time when Bessemer steel was fi~st made in 1860 steel was only known as the raw material for the cutlery and similar fine trades. It was very c<;>stly!, being made b}'." an expensive process from expensive imported material. In 1841 Russian and Swedish bar-iron imported by Hull merchants cost from £20. to ~35 per ton at Sheffield, the price being artificially mam~amed by the restriction ot exporta ticm by the Swedish Government. . All other requirements for rail:vays, shipbuilding, machinery, pipes, etc., were met by ir.on made in the puddling furnace or. the cupola. The discovery of mild steel, as it has· come to be called, changed all that, and although the foundry trade has
•
Foundry Practice 47 altered little, the manufacture of malleable shrunk to comparatively small dimensions.
iron has
HISTORY OF IRON FOUNDING IN THE UNITED STATES OF AMERICA
It is fairly well established that the aboriginal inhabita.nts of the ~merican Continent were unacquainted with the ~~e of iron. The highly civilized people of Peru and ~exic~ used copper only, and the Indians of North America did n?t _use iron until it was introduced by Europeans. This ignorance of iron is very striking evidence of the early period at which America was first inhabited, for ~t is very improbable that any people who once knew of iron would ever entirely lose that knowle~ge. Th~ hist.ory of iron in America, therefore, begins with the mvas10n of the Europeans who brought with them their. knowledl?e of the Catalan forge. Iron ore was. ~rst discovered 111 1585 by Sir Walter Raleigh's expedit10n on Roanoke Island. In 1608 a quantity of ore was shipped to England and smelted, and seventeen tons of metal produced. This was the first iron made from A.mer~cai;i ~He. The first attempt to establish ironworks 111 Virgima ended disastrously and the first works put down were in the province of Massachusetts Bay in 1643. The industry flourished and was gradually ex
FIG. 22. The First Casting Made in America.
Reproduced by permission f r o m Spring's NonTechnical Chats on
Ir0<1 and Steel.
ten~ed to other provinces, the abundance of timber available for charcoal being of great advantage. It has already been panted out that the British Government interfe'red with the development of the trade by prohibiting the use of mills and forg:es for making finished iron, compell111g the trade to be restricted to the manufacture of pig iron for export to England, except such quantities as could ?e used in the forges and mills already m work. !tfter the War of Independence heavy du!ies :vere put on imported iron, and the immigration of skilled artisans and workpeople from Europe was encouraged. In 1810 the annual value of iron and its
•
Merit Badge Examinations
manufactures was estimated at twelve to fifteen million dollars, and the value of imported iron at four million dollars . Heavy duties continued to be levied for the purpose of protecting the native works, and a great c~mtroversy arose between 1828 and 1833 upon. these duties.
In 1850 the quantity of pig iron made m the States was 564,755 tons, so that 60 per cent. of the iron used was home made and 40 per cent. imported. From 1850 the manufacture of iron rapidly increased, so that in 1860 the pig iron output was 821,22.3 tons, in 1870 1,665,178 tons, in 1880, 3,835,191 tons, m 1890, 9,202,703 tons, in 1900, 13,734,860 tons, in 1910 it was 27:298,545 tons, and in 1916, 39,434,797 tons. The product10n has therefore been about doubled every eleven years on the average. No other country in t~e wor~d ca? show such a development as this at any period of its history .. Germany comes nearest with abovt half the product10n .at each decade, but in the earlier years before 1870 the district of Elsass-Lothringen, which now produces a large quantity, was not included. -~
The-American expansion has been brought about .by the development of the country and by the possessi.on of great resources for iron-making in t~e Lake Supe:10r ores and Connelsville coke. The enterprise and orgamzation necessary for bringing these ma~erials togeth~r gave an admirable opportunity for the display of American energy and ability. The transport of ore a~ross the Lakes and its conveyance to the furnaces at Pittsburgh and other places is a triumph of engineer_ing skill and business capacity which has no parallel 111 any other part of the world. . .
From time to time the output of iron m the States has exceeded the demand, and the ironmaster there has then had to consider whether he should dispose of the surplus in outside markets or reduc.e . his make. T~e Pittsburg furnaces are too far from tide-water to admit
. of any iron from them being shipped overse3:, but the Southern furnaces in Alabama are able to put iron f.o.b .
. at Pensacola for about a dollar per ton. Pensacola is a cotton port, and there are, therefore, opportuni~ies of shipping iron in ships ta_king cotton to Europe which are
..
T
Foundry Practice 49
not loading their full carrying weight. In this way it has been possible to ship pig iron to Northern European ports such as Bremen, Hamburg, Rotterdam, etc., and to Mediterranean ports such as Genoa, Savona, etc., at a cost which would compete with British iron. But the geographical position of the American works generally is such that any serious competition in outside markets is not to be looked for. The Canadian markets, on the other hand, except those on the St. Lawrence river, are open to American competition, and as Canada has up to the present not developed any ore or coal-fields which will provide for her rapidly increasing population it would appear to be in her interest commercially to cultivate trade with her best market, which over a great extent of her territory is that of the States. In the Western States the absence of coal and ore in large quantities renders it difficult to establish the manufacture of iron as a national industry, and supplies of iron are obtained from the Eastern States. Imports into Western ports such as San Francisco and Seattle are received from Europe, but recently the Chinese works have sent in considerable quantities. It is probable that as the Chinese iron trade develops the requirements of the Western States of America will be largely supplied by that market.
•
50 Merit Badge Examinations
GLOSSARY OF FOUNDRY TERNIS
Air-Dried
Air-Furnace
Alloys
An ch qr
Anneal . Baked Core
Bars
Basin
Bath
Bead-Slicker
Bed Charge
Bedding"In Bellows
Bench
Bench Molding Binder
Refers to a core that has dried or partially dried in the air before baking. A furnace for melting iron, principally used in malleable practice. A combination of metals melted together. Appliance used to hold cores in place in molds. To soften by heat. A dry sand core which has been subjected to heat, usually in an oven, to render it hard, and to fix its shape; the' opposite of a green .core. Ribs placed across the cope portion of a flask. :~ · The portion of a q1pola below the tuyeres in which the molten iron collects. T he iron on the hearth of an air furnace. A tool for finishing a hollow place in a mold. The first charge of coke put into the cupola. Sinking a pattern into the sand. An ordinary small bellows used for blowing sand from the joint of a mold, and for blowing it from deep pockets in the mold. The fram ework table at w hich small molds are made. Making molds on a bench. A bar of wood or iron, with slotted ends to receive bolts, placed across a cope to hold the cope on the drag.
Block Sand
Blast
Blow Hole
Bod
Bosh Bottom Board Break-out
Breast
Bricks-Fire
Brush ·
Buckles
Butt-Ramming Butt Bull-Ladle
Calipers
Foundry Practice 51
Heap sand. Sand which has been used in molding. A current of air blown into the cupola by blower or fan. H ole in t he casting caused by trapped air or gas. A ball of clay used for closing the tap-hole-also called a bott. (See swab} · The board t hat the mold rest s on. A rupture of a mold permitting metal to flow out at the joint. Also called a run-out. The clay put into the opening, above the spout, t o form t he tap-hole. Bricks made of fire clay used for lining cupolas and air-furnaces. A brush for sweeping sand from the joint of molds. ·The brush is made of wire. Swellings in the surface of a mold due t o the generation of st ea m, below the surface, which cannot escape. Ramming w ith flat end of rammer. The large round end of a rammer. A two-man ladle used in carrying molten metal. A measuring tool for ascertaining the outside diameter of cylindrical bodies. ·
Camels' Hair Brush A brush for applying blacking to the surface of molds.
Casting
Chaplet
The ir on, brass or alloy art icle or pari. that is obtained as a result of pouring molt en meta! into a mold. A piece of metal, shaped in va rious ways, placed in a mold to support a core.
52 Merit Badge Examinations
Charge
Charging Door
Cheek
Chill
Chilled Casting
Chuck
Churning
Cinder Bed
Clamping Bar
Clamps
Clay Wash
Cold Sheet
Contraction Cope Cope Down
The iron and fuel placed in a cupola or air-furnace. The opening in a cupola or air-furnace through which fuel and metal are introduced. The middle part of a three-part flask . An iron surface, sometimes watercooled, of a mold, used to chill the molten iron rapidly and thus produce a hard surface on the casting. A casting made in a chill mold, which has cooled very rapidly. Small bars set between the cross bars of a flask. Feeding metal into a casting with an iron rod, through the feeder or riser. A layer of cinders placed beneath a mold. Gas, from the mold, escapes through the cinders and is led off through pipes. A bar used to tighten clamps on a flask. Devices for fastening copes and_ drags together. Clay, thinned with water and used as a coating for gaggers and flasks. An imperfection in a casting due to the metal entering t he mold by different sprues, and cooling, failing t o unite on meeting. Decrease iri volume due to cooling. The upper half of the mold. To build projecting bodies of sand on the surface of the cope to form surfaces of the casting which are below the level of the joint of the drag.
,..
Core
Core Box Core Oven Core Plate
Core Driers
Core Print
Core Wash
Corner T ool
Crushing
Crucible Zone Cupola
F oundry P ractice 53
A body. of sand, either green or dry, placed m a mold to form a cavity in t he casting. T he box in w hich the core is formed. An oven in which cores are baked.
An iron plate on which a green core is baked. A form w hich holds the core in shape w hile it is baking. A cavity in a mold in which the ends of cores are set; also a projection on a pattern w hich forms in the sand an impression used in locating a core and in holding it in place. A blackening mixture with which cores are painted: A tool for slicking the corner of the mold, inaccessible to the ordinary fo rm of finishing tools. The pushing out of shape of core or mold, when two parts of the mold that do not fit properly meet. The basin of a cupola. A shaft furnace for the melting of iron, the iron and fuel being charged in alternate layers, and combustion promoted by air blown in at t he bottom of the furnace.
Daubing Fining cracks in cores or plastering . a cupola after heat .
Double Cutter A molding slicker and spoon-slicker. Draft T he taper on a pattern that makes
it possible to draw it from the sand. Drag T he lower half of the mold or flask. Drawing the PatternLift ing a pattern from the sand of
a completed mold. Draw Plate A plat e put into a pattern t o be used
for drawing the pattern.
54 Merit Badge Examinations
Draw Nail
Draw Peg Draw Screw
Draw Spike Drop-Out Dull Iron
Dryer
Dry Sand Mold
Ears
Eye-Bolt
Feeding
Fin
Flow-Off Gate
Flange· Tool
Flask
Flat-Back
Flat Gate
A pointed rod of iron or steel driven into a wooden pattern to act as a handle to withdraw it from the sand in the mold. A draw screw, A rod screwed into a pattern to act as a handle for drawing a pattern. See draw nail. The falling away of a part of a mold. Iron not as hot as it should be for best pouring. A metal form, of the same shape as a core, in which the latter is placed while being baked. A mold which has been baked in an oven to fix · its shape permanently and to give it a hard surface. The lugs on the cope part of a flask into which tfre pins on the drag fit. A bolt with a ring welded at one end. Pouring metal into the feeder while the casting is solidifying. Metal that has run into an imperfect joint in the mold. An opening through which the metal flows after the mold is filled . A tool for furnishing the edges of flanges in a mold. The framework of wood or iron in which the sand is packed while being molded around a pattern. A pattern with a flat surface at the joint of the mold. Thus a flat-back pattern lies wholly within the drag and the joint of the cope is a plane surface. A wide gate with a narrow opening into the mold, used for pouripg thin flat castings.
Floor Molding Flux
Flow-Off
Follow Board
Foundry Frozen Iron Gaggers
Gate
Gate Stick
. Gating Patterns
Green Core Green Sand Green Sand Core
Green Ladle 'B:and Ladle Hand Squeezer
Hot Metal Hay Rope
Heap Sand Hearth
Foundry Practice 55
Making molds on the foundry floo r. A fusible material containing lime, such as limestone, charged il;lto the cupola to thin the slag. A channel cut from a r iser to permit metal to flow away from it when it has risen in the riser to a certain predetermined height. A board in which the pattern lies to the parting line. A place where castings .are made. Iron which has solidified. Metal supports used to reinforce the sand in the cope. The hole in the cope through which the molten metal is poured into the mold. A stick set in the cope while it is being rammed to form the passage into t he mold through which the molten metal is poured. Arranging patterns on a backbone, so that sprues w ill be formed by the backbone and its connection to the pattern when the mold is made. A core that is not baked. Sand that is in a damp state. A core made of green sand ; one that is not baked. A ladle w hose lining is not dry. A small ladle carried by one man. A molding machine in which the sand is compressed to the proper density by pressure applied by hand to the outer surface of the mold. Metal hot enough to flow easily. A rope of twisted hay, used to form the basis of cores made on arbors. Green sand from the foundry floor. That portion of an air furnace on which the iron is melted.
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"
ll
I
'
Merit Badge Examinations
Heat
Hern Gate
. Hub Tool
Jarring Machine
Joint
Lifter
Loam
Loam-Mold
Machine Molding
Malleable Casting
Match Plate
Melting Zone
Molding Board
Molding Machine
The melting period of a cupola or air-furnace. A semi-circular gate to convey iron over or under · certain parts of a casting, so that it will enter the mold at or near the center. Also used as a skim gate. A tool for finishing the mold of pulley hubs. A molding machine in which t he sand is packed by the sand pattern and flask being raised and dropped upon a table, the sand itself forming the ramming medium. The portion of the mold where the cope and drag come together. The upper surface of the drag and the lower surface of the cope. A molder's t ool with a flat end at right angles ta the stem, to lift loose sand from deep pockets in the mold. A mixture of molding sand and clay used for making loam molds. A mold built up of brick work, iron plate, etc., covered with loam which is afterward baked on. The operation of making molds on a molding machine. A hard brittle casting of white iron, which is rendered tough and malleable by annealing under certain conditions. A plate to which the pattern is fastened at the parting line. The portion of the cupola above the tuyere Zone in which the iron is fused.
· The board on which the pattern is placed when beginning to make the mold. A machine, operated either by hand or power, for making molds.
-
Molding Sarid
New Sand
Paraffine-Board
Parting Parting Sand
Patching Peeling
Pattern
. Peen
Peen-Ramming
Pee Gate
Pins
Pit Molding
Pipe Tool
Pouting Basin
Foundry Practice 57
Sand suitable for forming into molds. Sand that has not been used for molding. A board impregnated with paraffine on which patterns are mounted for use on the molding machine . The place on which a pattern is split. A fine, sharp, dry sand dusted on the joint of the mold to prevent the cope and drag from adhering to
· each other. Repairing broken parts of the mold. The ready dropping away of sand from a casting. The object of wood; metal, or other material, whose shape it is desired to reproduce in metal. T he sand of the mold is formed around the pattern, which is later withdrawn, leaving a cavity of its exact size and shape to be filled with molten metal. The flat -pointed end of a rammer. Also, the operation of ramming with the peen end of a rammer, as peening the sand. Ramming with the wedge end of the rammer. A round gate leading from a pouring basin in the cope to a basin in the drag, whence sprues lead to the mold. The projections on the drag of a flask which guide and hold it in position with relation to the cope. Making molds in pits in the foundry floor. A tool for finishing the surface of pipe molds. A basin formed in the cope into which the iron is poured.
Merit Badge Examinations
Power Squeezer
Pumping
Rammer
Ramming
Rapping
. Rapping Iron
Riddle
Riser
Roll Over Machine
Runner
Runner Box
Scabs
A molding machine in which the sand is compressed to the proper density by pressure, applied by compressed air to the outer surface of the mold. The action of feeding iron to a casting from a shrinkhead by forcing it in with a rod moved up and down in the shrinkhead. The tool used by the molder for packing sand in a flask around a pattern. · They are made of w.ood in the smaller sizes, known as hand rammers, and of iron in the larger. The action of packing sand around a pattern in a flask to form a mold. Striking a pattern to loosen it in the sand. An iron bar used to strike the drawnail in order to jar the pattern preparatory to dr;wing. A sieve for sifting sand on a pattern. A gate formed over a high portion of a mold to act as an indicator when the mold is filled with metal, and also tci act as a feeder to supply iron to the castings as it shrinks in passing from the liquid to the solid state. A molding machine in which the mold is rolled over before the pattern is drawn. A deep channel formed in the top of a cope, connecting with gates, into which the molten metal is poured. A set-off box in which a runner is formed. Imperfections in casting due to portions of the surface of a mold breaking away.
Foundry Practice 59
Scabbed Castings Scrap Iron Sea Coal Skimmer
Skimming
Skin Drying
Slag Set Gate
Set-Off Box
Shrinkhead
Shot
Skeleton
Skim Cores
Skim Gate
Skin-Dried Mold
Slag
Soldiers
Castings having rough surfaces. Metal to be remelted. Soft coal, finely ground. A piece of iron used to prevent dirt from flowing into the mold when pouring a casting. Holding back the dirt on the iron when pouring. Drying only the surface of the mould. Impurities fl uxed from the cupola. A gate patt ern used to form a gate or sprue set against the pat tern. A small box, open at the top and bottom, fastened to the top of a cope to contain portions of a mold projecting above the cope. A large riser containing a sufficient body of metal to act as a feeder as the metal of the casting contracts in solidifying. Globules of metal formed in the body of a casting, and harder than the remainder of it. A metal framework on w hich a fl at core is built.
· Cores Bet in skim gat es to act as skimmers. A sprue so arranged as to drain any impurities from the surface of the molten iron, as it flows into the mold, and restrain them from entering the mold. A green sand mold whose surface has been baked for a depth of an inch or more. The earthy impurities fused in the melting furnace, together with the fused flux charged w ith the fuel and metal. Wooden blocks used to reinforce sand when molding.
60 Merit Badge Examinations
Spongy Castings
Slag-Hole
Slicker
Slip
Slurry
Snap-Flask
Spindle
Spindle Seat
Split Pattern
Spoon Slicker
Spring Draw-Nail
Sprue
Sprue Cutter
Stack
Stool
Castings in which the iron 1s very open-grained. The opening in a cupola through which slag is · withdrawn. An elongated, flat, thin piece of steel used for smoothing the surface of molds. A wash applied to the surface of loam molds. The mixture used to fill in the joints of cores. A flask hinged at the corners, and separable at one corner, so that it may be opened and removed from around the completed mold. The rod or .center on which a sweep is revolved. The socket in which the Spindle revolves. A pattern made in two or more parts. A finishing tool for a mold, the end of which is spoon-shaped. A tool used for drawing patterns, especially green patterns. The channels leading from the gate to the mold. Also, the metal which solidifies in these channels after the casting has cooled. A piece of metal, used to cut channels in the joint to conduct iron from the opening gate to the mold. Also a brass tube used to cut the pouring gates in the copes of machinemade molds. The part of a cupola extending from the top of the melting zone to the level of the charging door.
_The support for a green sand core on a molding machine.
Stooling
Stool Plate
Strickle
Strike
Foundry P ractice 61
The process of supporting greensand cores in machine molding w hile the pattern is being draw n. The plate on a molding machine where stools are mounted. A strike w ith a form cut in one edge to form a regular surface on a mold. A flat bar of iron or wood used for striking or sweeping excess sand from the top of a mold.
Stripping Machine A plat e on a molding m achine on w hich the mold is made and through w hich .the patterns are drawn from the mold.
Spout
Swab
Swabbing
Sweep
Sweep Finger
Sweep Work
Tap-Hole
Tight Flask
Trowel
Tuy ere
Tuyere Zone
A trough through which the molten metal flows from the cupola to the ladle. A sponge or piece of waste used to wet t he sand around a patt ern before drawing it from the sand. The action of applying water t o a mold. A piece of wood or iron revolved about a center to fo rm the surface of a mold. The metal piece by means of w hich the sw eep is attached to t he spindle. Making molds with sweeps it13tead of patterns. The opening in a melting furnacecupola or air-through which molten metal is w ithdraw n. A flask wit h rigid framework-the opposite of a snap fl ask. A molcler's t ool used fo r slicking the surface of a mold. An opening through w hich the air passes from the wind box into the cupola. . The port ion of a cupola in the region of the t uyeres, where combustion takes place.
62 Merit Badge Examinations
Upset
Vent
Vent-Wire Vibrator
Vibration Frame
Weak Sand Whirl Gate
Wind Box
Alexander
Palmer
Spring
Wendt
Moldenke
Payne
West
West
Hood
Whiteley
A shallow frame set over a flask in which is formed a green sand mat ..:h. A small hole formed in a mold through which gas and steam may escape. A wire used for making vents. A device for rapping patterns by compressed air. A frame in which patterns are mounted when they are to be drawn in connection with a vibrator. Sand that will not hold together. A gate or sprue arranged to introduce metal into a mold tangentially, and to thereby give it a swirling motion. The chamb~r surrounding a cupola through which the air is conducted to the tuyeres.
BIBLIOGRAPHY Safety in the Foundry-National Foundries Assn.-Chicago. Foundry Practice-John Wiley & Sons. Non-technical Chats on Iron & Steel -Frederic K. Stokes Company. Foundry Work. McGraw - Hi 11 Book Co. The Principles of Iron FoundryMcGra w-Hill Book Co. Founder's Manual, D. Van Nostrand Co. American Foundry Practice, John Wiley & Sons. Moulder's Text Book-John Wiley & Sons. Common Commodities and Industrial Iron-Pitman & Sons-London. Iron Founding-Pitman & SonsLondon.
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An unsurpassed library on Scout activities and 'V'bdltiOns prepared by experts, and carefully revised and kept up-to~ date. Instruction in Merit Badge Subjects, technical advice and bibliography in each pamphlet. Also, when subject l~da itself, biography of a leader in that field, and a CIH$pter ota vocational guidance and self-help for the Scout. Cat. No. Subject Cat. No. Subject 330' Agriculture 3868 Indian Lore 3319 Angling 8888 Interpreting 8801 Animal Industry 8813 Journallllm. 8881 Archery 8863 Landscape GardeDIDg 8821 Architecture 8311 Leathercraft 3830 Art 88l0 Leather Work 8808 Astronomy 8378 Life Saving 8824 AthleUca 8387 Machinery 8806 A.utomoblllng 8338 Marksmanahlp 3308 Aviation 3839 Masonry 8313 Basketry 8351 Mechanical Drawing 8840 Beef Production m: =~c'9"ork 3862 Bee Keeping 3338 Music and Bugling :m ~l:1~.:~Ji1ng 8868 Nut cu1tnre
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