021512 Evaluation of Spot and Sweep Blasting

8/13/2019 021512 Evaluation of Spot and Sweep Blasting

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Evaluation of Spot and Sweep

Blasting as a Cost Effective Method

of Underwater and Outer HullSurface Preparation

Stephen Cogswell, BAE Systems Southeast ShipyardsPMT:Gordon Kuljian, Pete Ault, John Odwanzy

Non-Export Controlled Information Releasableto Non-US Persons: S2DSEA2012-0051


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Spot and Sweep, in progress



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Concept

Reduce Total Ownership Cost of cleaning andpainting underwater hulls on US Navy ships byleaving intact anti-corrosive on the hull during

repainting This paper is a result of the work being

accomplished by the NSRP SurfacePreparation and Coating Panel project team:Steve Cogswell, Pete Ault, Gordon Kuljian &John Odwazny



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Spot & Sweep to well adhered Epoxy

& , spot & sweep/fullremoval, edge check in progress

Spot & Sweep, DFT in tact epoxy7 to 15 mils



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Project Goals

Demonstrate commercial technology on US

Navy ships

Document performance issues

Identify process refinements

Determine life cycle cost impact

Develop NSI 009-32 language

Process requirements

Objective Quality Evidence (OQE)



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USS KLAKRING (FFG 42)

Demonstration in February, 2011

BAE Systems Southeast Shipyards, Jacksonville FL

Existing coating applied in November, 2002

Performed on freeboard and underwater hull

Data collected

Production rates

Adhesion of coating before and after cleaning

Extent of coating removed

Non-Export Controlled Information Releasableto Non-US Persons: DSEA-S2-2010-0118


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USS KLAKRING (FFG-42) Spot & Sweep

The surfaceSpot and sweep to existing welladhered epoxy coating



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Chariot Robotics

Articulating robotic head makinga turn. Vertical, cutting path



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Flow Hydro Cat

& , Chariot(left), Flow (right) Hydro Cat tracking vertically

Non-Export Controlled Information Releasable toNon-US Persons: DSEA-S2-2010-0118


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Adhesion Values, Spot & Sweep

1stand 2ndAC, cut through 2030 psi



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Hull Plating from the Side Shell

Retained for Laboratory Testing



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APL-65 Berthing Barge Dry-docking

Graving Dock, NAVSTA San Diego July 2011



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APL-65 Initial Condition

Calcareous Biofouling on flat-bottom

Heavy corrosion on Stern U/WPort side looking aft

Close-up of Stern Corrosion

Non-ExportControlledInformationReleasable

toNon-USPersons:S2DSEA2012-0051


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Spot and Sweep Demonstration (APL-65)

General result of high speed spot/sweep. Due to the wide-spread coating defects, much of the

underwater hull coating was removed to bare steel. This platform would not meet our criteria

of a good candidate for spot and sweep removal, however meaningful data was gathered.

Criteria appears to be in the 5% range of general defects, vs. 40% found on this hull.Non-ExportControlledInformationReleasable

toNon-USPersons:S2DSEA2012-0051


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APL-65 Initial Condition

After pressure washing, minor W/L grass remaining, heavy base plate

calcareous shell remaining on flat underbelly, widespread corrosion alongwelds and at stern.

Flat Bottom avg. DFT 21.4 mils

Starboard Mid-ship avg. DFT 18.2 mils

Centerline flat bottom fwd avg. DFT 38.4 mils

Initial Coating applied approximately yr 2000

Standard MIL-PRF-24647 system applied

Overall coating showed approximately 40% coating defects in the form of

blistering and isolated corrosion. Defects were predominantly wide-spread.

Job involved a complete WJ-2 water-jetting of the underwater hull and

freeboard - 19,000 ft2removed by Chariot Robotics Envirobot. Remainder of

hull coatings removed by men-on-guns (open cycle UHPWJ).

Spot and Sweep demonstration performed along bow underwater hull prior

to complete re-blast to SSPC SP-12, WJ-2



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Spot and Sweep Demonstration

Data (APL-65)

Trial runs were optimized at 30,000 psi with spray bar in highest position

from substrate. (9 GPM Pump)

Resulting surface - 25% bare steel, approx 75% red primer and grey mid-

coat (both MIL-PRF-24647 epoxy)

Run 1 stripping rate 3260 ft2

/hour Run 2 stripping rate - 1830 ft2/hour

Adhesion of initial epoxy (after A/F carefully sanded away and solvent

wiped: 1316 psi (3 dolly avg. ASTM D4541)

Adhesion of epoxy remaining after spot and sweep:

1615 psi (3 dolly avg. ASTM D4541)



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USS RODNEY M DAVIS (FFG-60) SPOT-AND SWEEP

DEMONSTRATION VIGOR SEATTLE FEBRUARY 2012INITIAL CONDITIONS - (after 5000 psi

pressure wash)

Hull coating in great shape. Less

than 0.5% overall coating defects.

Defects were generally isolated to

discharges, welds, rudder and

stabilizers. U/W hull last painted in

2003 (according to Port Engineer)

Coating average DFT - 30-35 mils

(Consists of primarily 17-20 mils A/C,

and remainder is A/F, as verified by

destructive Tooke Gage readings)

Initial A/C adhesion - 1414 psi

Practice Section Under Stbd, fwd

anchor , fwd of forward sonar

Demo section - FWD of FR 100 STBD,

aft of forward sonar Non-Export Controlled Information Releasableto Non-US Persons: S2DSEA2012-0051


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RODNEY DAVIS (FFG-60) DEMONSTRATION

INITIAL JEWEL CHECK DEPLOYMENT OF ROBOT TO HULL

START OF PRACTICE SECTION:

EXISTING MIL-PRF-24647 SYSTEM

RED EPOXY PRIMER

GREY EPOXY MID-COAT

(WHITE IS SUBSEQUENT TOUCH UP

EPOXY OF ANCHOR CHAIN DAMAGE)

SSPC-SP-10



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RODNEY DAVIS (FFG-60) DEMONSTRATION

HIGH PRESSURE SWEEP LEFT LESS A/C

PREDOMINANTLY RED PRIMER

LOWER PRESSURE SWEEP LEFT CONSIDERABLY MORE

A/C WITH MINIMAL REMOVAL DOWN TO RED PRIMER

AFTER OPTIMIZING

REMOVAL TO GREY A/C,ROBOT PERFORMED

SPOT-AND-SWEEP AT

2100 FT2/HOUR

DFT OF REMAINING

GREY - 16.5 MILS

DFT OF REMAINING RED

8.5 MILS

RESULTING SURFACE IS

INTACT A/C WITH

COMPLETE A/F REMOVAL.

POORLY ADHEREDCOATING HAS BEEN

REMOVED TO BARE

METAL.

FORWARD PRACTICE SECTION



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RODNEY DAVIS (FFG-60 DEMONSTRATION)

DEMONSTRATION SECTION

BEFORE SPOT-AND-SWEEP

DEMO SECTION DURING

SPOT AND SWEEP

TENSILE ADHESION AFTER SWEEP

GREY A/C 2170 PSI (AVG OF 3)

RED A/C - 2189 PSI (AVG OF 3)

REMAINING GREY DFT - 18.8 MILS

REMAINING RED A/C 8.9 MILS

OBSERVED PRODUCTION - 695 FT2/HOUR



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NSRP Spot and Sweep Blasting Project

Remember - We are trying to reduce this:

Non-

ExportControlledInforma

tionReleasable

toNon-USPersons:S2DSE

A2012-0051


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DRAFT- PROCESS FOR SPOT AND SWEEP BLAST DEMONSTRATION

1. The spot and sweep process preformed by the Chariot Robotics unit (or equivalent) may beused for all areas of the underwater-hull and freeboard on approved surface ships. For areas not

prepared using the Chariot Robotics or equivalent; Ultra High Pressure (UHP) lances, abrasiveblasting, may be used to create either an SSPC SP-12 WJ-2/M surface or an SSPC SP-10 surface.SSPC SP-3 Power tool cleaning may be authorized for fairing in the spot and sweep surface as

required.

2. The contractor shall inspect the existing coating on the hull and shall determine the sequenceof the epoxy coatings currently on the hull prior to blasting. The anticipated sequence is red

primer followed by gray epoxy tie coat. The contractor shall note these colors for use in

NAVSEA inspection of the hull prior to application of the first coat of epoxy primer.

3. The Chariot Robotics unit (or equivalent) shall be set up to accomplish the following:(a) Remove all rust and fouling from areas of bare metal to create a SSPC SP-12, WJ-2/M

surface condition in accordance with specified NAVSEA Standard Item 009-32, FY 12 Change 1processes.(b) Remove all antifouling coating and remove approximately 1/2 of the thickness of the current

epoxy tie coat thickness from the underwater hull area.(c) Remove all silicone alkyd, regardless of coating thickness, and remove approximately 1/2 of

the thickness of the current epoxy topcoat from the freeboard area.(d) Smoothly feather or transition from areas of bare metal to the retained epoxy primer/tie coat.

Areas of sharp or "step" transition between bare metal and paint shall be noted by the NAVSEArepresentative for detailed inspection. *under review: Feather edges where the Chariot Robotics

unit (or equivalent) leave behind markings in the existing paint (concentric circle areas whichsome describe as crop circles).Non-


tionReleasable


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4. Upon completion of standard zones or work areas, in accordance with current, standard

contractual requirements, the contractor shall inform the NAVSEA representative when they areready to apply the first coat of primer to the zone or work area. NAVSEA representative shall

conduct all standard data reviews and inspections on bare metal areas in accordance withspecified Standard Item 009-32 requirements. Areas of retained paint shall be visually inspectedand shall satisfy the following:

(a) There shall be no more than two colors of paint visible in any area of retained coating.Inspectors shall observe the red primer adjacent to any bare metal areas and then continue

observations into the bulk of the retained epoxy. Gray epoxy may be retained on top of thered primer, but any visual evidence of additional coats of red or black paint on top of the grayshall be cause for closer inspection. Closer inspection shall be conducted from a minimum

distance of 3 feet. Upon closer inspection, a solvent-wipe test with a white rag shall beconducted using the antifouling coating clean-up solvent. If the solvent wipe test shows

color transfer onto the rag, the area shall be rejected. Rejected areas shall be cleaned againuntil no color transfers to the rag.

(b) There are no areas of sharp transition or steps between bare metal and paint. Any such areas

shall be inspected and tested with a dull putty knife to determine adhesion. If the paint flakesor can be dislodged, the area shall be rejected and cleaned again to remove the loose paint.

(c) *Under review Effort will be needed to smooth out the transition areas where partial blastedareas occur next to bare steel blasted areas. Sharp edges shall be removed in accordance withSSPC SP-3 and the areas feathered for a smooth transition.

(d) Measurements of existing DFT shall be recorded for historical purposes in accordance withSSPC PA-2.

Non-


tionReleasable


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5. Upon approval of the surface preparation, the contractor shall apply one coat of AC primer, in


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accordance with established Standard Item 009-32 requirements to all areas in the zone or work

area (i.e., bare metal and retained epoxy primer) to achieve the specified 5-7 mil dry filmthickness. The contractor is not obligated to apply a thin or varied primer thickness when

traversing areas between bare metal and retained epoxy. Again following standard practices,SUPSHIP shall inspect the zone or work area coating thickness. Because the coating thicknessretained will vary notably, DFT readings shall be taken and recorded; however high DFT

readings shall not be means for rejection, such readings shall only be taken for documentationpurposes. In place of DFT readings for determining proper coating thickness, WFT readings

shall be taken and recorded on each coat to confirm proper coating thickness (i.e. follow the 009-32 requirement for taking WFT readings in place of DFT readings for accept/reject criteria). All

other QA requirements of 009-32 shall be accomplished.

6. Once the primer has cured to overcoat the surface area shall be inspected for edge lifting of the

remaining epoxy that was over coated. This inspection shall be conducted at a maximumdistance of 15 feet. The curing epoxy primer will lift any loose edges of the existing coating as it

cures that may not have been visible during the initial surface preparation inspection. Theseareas shall be prepared in accordance with SSPC-SP-3 and primed.

7. For underwater hull areas, apply second or tie coat of epoxy and first coat of antifouling inaccordance with Standard Item 009-32 requirements (using WFT readings).

8. For underwater hull areas, apply complete antifouling system in accordance with StandardItem 009-32 requirements and note final coating thickness. Again, use WFT readings in place of

DFT readings for determining proper coating application, with DFT readings being recorded fordocumentation purposes.

9. For freeboard areas, apply second coat of epoxy then the topcoat in accordance with StandardItem 009-32 requirements (using WFT readings).

10. The contractor and NAVSEA representative shall retain time, cost, or productivity metrics to

report to NAVSEA and to be used to provide supporting data for any future Standard Item 009-32 proposal to incorporate spot and sweep processes.

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Potential Cost Savings to the Fleet

Defining the cost savings is a deliverable of the project due March 31,

2012.

Schedule and budget savings measured against the life cycle of the

coating system to docking evolutions.

Freeboard preservation may be the land of opportunity. Non Critical,often top coated for aesthetics only. Easily inspected. Greater than

double the square footage over the UWH. Cost per square foot for

surface preparation freeboard and UWH are close.

Draft document was explained to inspectors who accomplished the G

point on the following day. Their comments/feedback will be

incorporated into final revision. PSNS, NWRMC, VIGOR.

We have successfully demonstrated Spot and sweep on both coasts to

the draft document.

Non-Export Controlled Information Releasable

to Non-US Persons: S2DSEA2012-0051


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QUESTIONS

Special thanks to the Project Team:

Chariot Robotics; John Odwazny, Gordon Kuljian

Elzly technologies; Pete Ault

NAVSEA: Mark Ingle, David CisconThe commands of FFG-42 and FFG- 60, PSNS code 400, SERMC

and the PMTs of BAE Systems SSYI and Vigor Shipbuilding

Non-Export Controlled Information Releasableto Non US Persons: DSEA S2 2010 0118

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021512 Evaluation of Spot and Sweep Blasting

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