PPI NBR: H (REV 01) DATE: September 02, 2005

Transcription

1 PPI NBR: 60-00H (REV 0) DATE: September 0, 00 PRESERVATION PROCESS INSTRUCTION (PPI) for MCM and MHC Class Propeller and Metallic Underwater Hull Appendages to be used in conjunction with CORE PPI with a Cleanliness Level of SSPC-SP-0 Surface Preparation MCM & MHC Propeller and Metallic UWH Appendages PPI

2 . SCOPE:. Cleaning, Surface Preparation and Painting Requirements for MCM and MHC Class Propeller and Metallic Underwater Hull Appendages.. If the PPI checkpoint criteria are met, the following table provides the maximum service life expectancy for the listed system. Coating System Life Expectancy: Area System Life Expectancy MCM and MHC Class Propeller and Metallic Underwater Hull Appendages Ameron 8, F0, F, F, F0, and F - 6 years. REFERENCES: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING).c. MSDS and NAVSEA approved manufacturer s ASTM F 78 sheets, Shipbuilders and Marine Paints and Coating Product / Procedure Data Sheet for Coating Systems Being Applied.. APPENDICES: (REFER TO CORE PPI EXCEPT FOR APPENDIX ). REQUIREMENTS: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING) NOTE: WHERE REF..B AND THE INSTRUCTIONS IN THIS DOCUMENT CONFLICT, THE INSTRUCTIONS IN THIS DOUCMENT SHALL BE USED..8. All blasting and coating application work shall be accomplished when the Relative Humidity is less than 80%. All coating application shall take place when the substrate temperature is at least 0 F and at least F above the dew point temperature..8. (NOT APPLICABLE TO THIS PPI). PRE-SURFACE PREPARATION: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING). PRE-SURFACE CONDITIONING: Before surface preparation the CONTRACTING REGIONAL MAINTENANCE CENTER shall have all welds, protrusions and spikes ground smooth; pits in welds shall be ground out; all weld splatter shall be removed. 6. SURFACE PREPARATION: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING) NOTES: ALL COMPONENTS SHALL BE PRESSURE WASHED INITIALLY IN CONJUNCTION WITH THE REST OF THE UNDERWATER HULL. USE DETERGENT AND FRESH WATER FOR REMOVING LIGHT DEPOSITS OF GREASE, OIL, DIRT, DUST AND SIMILAR CONTAMINANTS WHICH REMAIN AFTER WATER WASHING. 6. Perform surface preparation method of abrasive blasting as specified in accordance with SSPC-SP 0. Abrasive blast media shall be virgin aluminum oxide grit. Prior to use, abrasive shall be sampled and tested for contamination as outlined in MIL-A-6B. Accomplish a surface profile of.0.0 mils (7-00µm). 6.. Remove spent abrasives from the piece by either vacuuming (preferred method), blowdown with clean, dry compressed air, or by brushing with clean, dry, foxtail-type brushes dedicated for this purpose (or any combination of these methods). On sub-assemblies, ensure removal of all grit from mating and bearing surfaces. 6.. Subsequent to final blasting and prior to coating application metallic surfaces shall be handled using clean gloves. The exposed metal shall remain contaminant free. 6. (NOT APPLICABLE TO THIS PPI) 6. (NOT APPLICABLE TO THIS PPI) MCM & MHC Propeller and Metallic UWH Appendages PPI

3 6.. (Surface Profile s): Accomplish IAW Ref..d. Take a minimum of profile measurements on any one assembly using TESTEX X-Course Press-O-Film profile tape. Average profile should be between.0.0 mils. Abrasive manufacturer, type and mesh size used shall be entered on Appendix along with the TESTEX PRESS-O-FILM tapes used to measure surface profile Should a single reading indicate an insufficient profile, take a sufficient number of profile measurements to determine the extent of the under blasted area. Repeat blast and steps of 6.. until an average profile of.0-.0 mils is achieved Should a single reading be found to exceed mils, determine the extent of the over-blasted area. Should the sum of areas exceed one ft, buff these areas using hand tools and repeat steps of 6. to achieve.0.0 mils. Should areas total less than one ft, record location of areas that are over-blasted to allow for downstream monitoring of the coating system (NOT APPLICABLE TO THIS PPI) 6... (NOT APPLICABLE TO THIS PPI) 7. PAINTING REQUIREMENTS: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING) NOTES: THE COATING SYSTEM TO BE APPLIED SHALL BE A FIVE COAT SYSTEM OF AMERON 8. THE COATING SYSTEM SHALL CONSIST OF A PRIME COAT OF F 0, A ST STRIPE COAT OF F, A MID COAT OF F, A ND STRIPE COAT OF F 0 AND A TOPCOAT OF F. ALL ITEMS SHALL BE BLASTED AND COATED AT THE POINT IN THE FABRICATION SEQUENCE WHICH WILL ENSURE ADEQUATE COATINGS APPLICATION WITH MINIMAL TOUCH-UPS AS REQUIRED. TO MAINTAIN PROPER SURFACE CONDITIONS AFTER COMPLETION OF THE SURFACE PREPARATION CHECKPOINT METHODS SUCH AS USE OF DEHUMIDIFICATION EQUIPMENT, ENVIRONMENTAL ENCLOSURES, AND SURVEILLANCE/MONITORING OF THE PREPARED SURFACE SHOULD BE EMPLOYED. COATING APPLICATION SHOULD START WITHIN HOURS OF BEGINNING THE FINAL ABRASIVE BLAST CLEANING. COATING APPLICATION SHOULD BE CONTINUOUS THROUGH COMPLETION OF THE AREA TO BE COATED. IF COATING APPLICATION HAS NOT BEEN STARTED WITHIN HOURS OF BEGINNING THE FINAL ABRASIVE BLAST CLEANING, THE SURFACE PREPARATION CHECKPOINT WITH THE EXCEPTION OF SURFACE PROFILE WILL BE REPEATED. 7.. For all full coats applied, apply at a minimum WFT of.0 mils to a maximum WFT of 9.0 mils. 7. DRY FILM THICKNESS MEASUREMENTS: Accomplish IAW Ref..b and as stated below. 7.. Use a gage suitable for non-ferrous materials calibrated using standard shims over abrasive blasted stock of copper-nickel and bronze (nickel-al bronze, alloy (9800)). Take a minimum of DFT measurements on any single sub-assembly. Record measurements on Appendix. 7.. The average DFT per coat shall be.0.0 mils. For Intermediate Coat and topcoat the average DFT per coat shall be determined by measuring the current, total average DFT and subtracting the average DFT recorded for all previous coats. If the average DFT is low then additional coating shall be applied to bring the coating thickness into the appropriate range. Should the coating thickness be too high, the coating should be removed by hand-sanding in the high regions to bring the coating into specification. 7.. No single, total DFT reading may be less than.0 mils for the primer coat, 6.0 mils for the intermediate coat and 9.0 mils for the topcoat. If a single reading indicates insufficient film thickness, take enough DFT measurements to determine the extent of thin area(s). Mark these areas with a suitable oil free chalk. Apply additional coating to achieve required average thickness in these areas. 7.. No single, total DFT reading may be greater than 7.0 mils for the primer coat,.0 mils for the intermediate coat and.0 mils for the topcoat. If this occurs take a sufficient amount of measurements to determine the heavy areas. Sand the heavy areas using hand tools until the DFT falls within the specified average required in these areas. MCM & MHC Propeller and Metallic UWH Appendages PPI

4 7. RE-COAT PERIODS: The minimum re-coat period shall be hours between all coats (based on 70 o F and 0% RH). The maximum re-coat period shall be 7 days between all coats (based on 70 o F and 0% RH). If the drying time exceeds 7 days, solvent wipe entire area with a solvent (e.g. MEK) and apply a mist coat of.0.0 mils WFT prior to the next coat. If the minimum re-coat period is not conformed to, the coating shall be removed and re-applied. 7.. (Pot Life): Verify pot life has not been exceeded as specified IAW Ref..c. 7.. Relative humidity shall be maintained at less than 80% throughout the application and cure time for the coating system. 8. PRIMER COAT APPLICATION: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING) 8. Apply Ameron 8 F0 primer IAW Table 6--, III. During application, immediately brush out any runs, drips, sags or puddles. 8.. (Dry Film Thickness): Accomplish dry film thickness measurements IAW item ST STRIPE COAT APPLICATION: 9. Apply Ameron 8 F stripe coat IAW Table 6--, III. Apply by brushing to all component edges, welds, bolts, and nuts extending ½ to inch from edge. During application immediately brush out any runs, drips, sags or puddles. 0. INTERMEDIATE COAT APPLICATION: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING) 0. Apply Ameron 8, F intermediate coat IAW Table 6--, III. During application, immediately brush out any runs, drips, sags or puddles. 0.. (Holiday Inspection): Perform a visual holiday check. Mark holidays for repair with a suitable oil free chalk. 0.. (Dry Film Thickness): Accomplish dry film thickness measurements IAW item 7... ND STRIPE COAT APPLICATION:. Apply Ameron 8 F0 stripe coat IAW Table 6--, III. Apply by brushing to all component edges, welds, bolts, and nuts extending ½ to inch from edge. Also repair all holidays detected in 0... During application immediately brush out any runs, drips, sags or puddles.. TOPCOAT APPLICATION: (REFER TO CORE PPI EXCEPT FOR THE FOLLOWING). Apply Ameron 8, F topcoat IAW Table 6--, III. During application, immediately brush out any runs, drips, sags or puddles... (Dry Film Thickness): Accomplish dry film thickness measurements IAW item 7... FINAL INSPECTION: NOTE: ALLOW COATING TO DRY FOR 7 DAYS PRIOR TO IMMERSION. APPENDIX : QA INSPECTION FORM ENVIRONMENTAL READING APPENDIX : QA INSPECTION FORM SURFACE SOLUBLE SALT CONDUCTIVITY LOG APPENDIX : QA INSPECTION FORM SURFACE PROFILE LOG APPENDIX : QA INSPECTION FORM DRY FILM THICKNESS MEASUREMENTS (REFER TO THIS PPI) APPENDIX : CHECKPOINTS & MILESTONES COMPLETION & SIGN OFF LOG APPENDIX 6: PAINT APPLICATION EQUIPMENT & PAINT CONSUMPTION LOG APPENDIX 7: QA INSPECTION FORM WET FILM THICKNESS MEASUREMENTS APPENDIX 8: COATING SYSTEM (S) (NOT APPLICABLE TO THIS PPI) APPENDIX 9: QA INSPECTION FORM TEST FOR ASSESSMENT OF SURFACE CLEANLINESS MCM & MHC Propeller and Metallic UWH Appendages PPI

5 APPENDIX QA INSPECTION FORM - DRY FILM THICKNESS MEASUREMENTS SHIP: JOB ORDER: DATE: LOCATION: WORK ITEM: PARA. NO.: _ (I) (V) (G) PRODUCT BEING APPLIED: MAINTAIN SEPARATE LOG FOR EACH AREA/LOCATION, PREPARED OR PAINTED SURFACE. WHEN AN AREA IS DIVIDED INTO SEPARATE SECTIONS MAINTAIN A SEPARATE LOG FOR EACH SECTION. Indicate Indicate Type or DFT Gage Being Used: PARTIAL FINAL Coating Gage Manufacturer: System Serial Number of Gage Being Used: Seq. Date Last Calibrated: Current Calibration Due Date: Prime Coat: Topcoat: Stripe Coat: Intermediate Coat: Stripe Coat: ACCEPT CRITERIA PRIMER DFT TO MILS STRIPE COAT DFT TO MILS STRIPE COAT DFT TO MILS TOPCOAT DFT TO MILS INTERMEDIATE DFT TO MILS TOTAL SYST. DFT TO MILS ADJUSTMENT & MEASUREMENT-TYPE I PULL-OFF GAGES: BASE METAL READING AVERAGE VALUE Avg. of Gage Contractor (Signature): Avg. of Gage ADJUSTMENT & MEASUREMENT-TYPE I PULL-OFF GAGES: BASE METAL READING AVERAGE VALUE Avg. of Gage Contractor (Signature): Avg. of Gage Contractor (Print): _ Contractor (Signature): Govt. Insp. (Print): _ Govt. Insp. (Signature): Contractor (Signature): SAT UNSAT HOLIDAY INSPECTION SAT UNSAT SURFCE INSPECTION SAT UNSAT DFT COMMENTS: MCM & MHC Propeller and Metallic UWH Appendages PPI