Evaluation of “Spot and Sweep” Blasting as a Cost Effective ... - NSRP

Initial Inspection criteria and OQE3.7 Change the requirements of Column A (surface preparation) of Table One, Line 4 called out in 3.3 and accomplish alternativesurface preparation as follows:3.7.1 Remove all antifouling coating and remove approximately 1/2 of the thickness of the current epoxy tie coat thickness fromthe areas listed in 1.2.1 with the following exceptions: APU cavities and fairing plates, sea chests and hull openings up to valveflanges and sea chest strainers which will be prepared in accordance with 3.3.3.7.2 Smoothly feather or transition from areas of bare metal to the retained epoxy primer/tie coat in areas of sharp or "step"transition between bare metal and paint.3.7.3 Remove all rust and fouling from areas of bare metal to create a SSPC SP-12, WJ2M or WJ2L level of surface cleanliness inaccordance with 009-32, Change 1 of 2.1.3.7.4 Upon completion of the surface preparation of the areas listed in 3.7.1 apply one coat of antifouling primer, in accordancewith 009-32 of 2.1 including Table One, Line 4, Column B , Minimum DFT: 7-mils, Maximum DFT: 16-mils.4.2 There shall be no more than two colors of paint visible in any area of retained coating. Inspectors shall observe the red primeradjacent to any bare metal areas and then continue observations into the bulk of the retained epoxy. Dark gray epoxy may beretained on top of the red primer, but any visual evidence of additional coats of red or black paint on top of the gray shall be causefor closer inspection. Upon closer inspection, a solvent-wipe test with a white rag shall be conducted using the antifouling coatingclean-up solvent. If the solvent wipe test shows color transfer onto the rag, the area shall be rejected. Rejected areas shall becleaned again until no color transfers to the rag.4.3 There shall be no areas of sharp transition or steps between bare metal and paint. Any such areas shall be inspected andtested with a dull putty knife to determine adhesion. If the paint flakes or can be dislodged, the area shall be rejected and cleanedagain to remove the loose paint.Non-Export Controlled Information – Releasableto Non-US Persons: DSEA-S2-2010-0118