Preliminary Requirements

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURER'S MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS AND ALSO TO TAKE LOCAL REGULATIONS IN TO CONSIDERATION. MANUFACTURER'S DATA SHEETS CONTAIN INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES.

Procedure

1. SUBTASK 70-12-09-501-001 Abrasive Cleaning Procedure

   1. 

      CAUTION

      SURFACE TREATMENT (SUCH AS, ABRASIVE BLASTING), IF NOT DONE CORRECTLY, CAN CAUSE A SMEARED SURFACE. THIS MAKES SURFACE DEFECTS NOT EASY TO FIND DURING NON-DESTRUCTIVE INSPECTIONS. DIFFERENT MATERIAL AND PROCESSES WILL SHOW DIFFERENT EFFECTS. THUS IT IS VERY IMPORTANT TO FOLLOW VERY CAREFULLY THE INSTRUCTIONS IN THE STANDARD PRACTICES/PROCESSES MANUAL AND ENGINE MANUAL. IF CAREFULLY DONE, THE APPROVED NON-DESTRUCTIVE INSPECTION (ESPECIALLY FPI) WILL CONTINUE TO HAVE RESULTS THAT ARE VERY ACCURATE.

      

      CAUTION

      DO NOT USE THIS PROCEDURE FOR CLEANING OR STRIPPING TITANIUM PARTS BEFORE FPI. FOR OTHER PARTS, WHEN THIS PROCEDURE IS SPECIFIED FOR CLEANING PARTS BEFORE FPI OR FMPI THE PART MUST FIRST BE CLEANED BY SPM TASK 70-11-13-300-503 OR SPM TASK 70-11-16-300-503, WHICHEVER IS SPECIFIED IN THE MANUAL.

      

      CAUTION

      THE BLASTING CABINET AND MEDIA USED IN THIS PROCEDURE ON ENGINE PARTS MUST NOT BE USED TO STRIP CADMIUM PLATED PARTS OR CADMIUM PLATED/PAINTED PARTS, SUCH AS LANDING GEAR.

      

      CAUTION

      THE USE OF ALTERNATIVE SIZE MEDIA OR MATERIAL TO THOSE SPECIFIED IN THE PROCEDURE IS NOT PERMITTED UNLESS SPECIFIED DIFFERENTLY BY THE ENGINE MANUAL.

      

      CAUTION

      DO NOT PURCHASE RECYCLED/RECOVERED MATERIAL, USE ONLY NEW ALUMINIUM OXIDE ABRASIVE.

      Initially clean the parts - (Refer to TASK 70-11-03-300-503).

   2. Mask the part, as necessary, to prevent any material that can become caught in the part.

      1. Install CoMat 02-348 AIRSEAL MASK on the knife-edge airseals to prevent erosion of the thermal spray coating. If the CoMat 02-348 airseal mask is not sufficient to give the knife-edge airseal protection from the abrasive blast, install the CoMat 02-348 AIRSEAL MASK on the knife-edge airseal, and then apply a cover of masking tape from SPM TASK 70-34-18-380-501.

   3. Set the machine air pressure as follows:

      1. For pressure-type machine: 25 psi to 30 psi (172 kPa to 207 kPa).

      2. For suction-type machine: 50 psi to 60 psi (345 kPa to 414 kPa).

   4. 

      CAUTION

      ALWAYS APPLY MASKING TAPE OR INSTALL THE SPECIAL GUARDS TO THE COMPONENT SURFACES WHICH ARE NOT TO BE BLASTED. DO THIS BEFORE YOU BLAST THE COMPONENT. MAKE SURE NO BLASTING MEDIA GOES INTO THE COMPONENT AND BECOMES CAUGHT.

      

      CAUTION

      DO NOT BLAST HARDFACE COATINGS UNLESS SPECIFIED BY STRIPPING INSTRUCTIONS IN THE ENGINE MANUAL OR STRIPPING PROCEDURE. HOWEVER, BLASTING OVERSPRAY IS PERMITTED.

      

      CAUTION

      DO NOT ABRASIVE BLAST ON THE SAME AREA FOR MORE THAN TWO SECONDS; USE CONTINUOUS MOTION.

      Abrasive blast with CoMat 05-022 ALUMINUM OXIDE ABRASIVE for CoMat 05-197 ALUMINUM OXIDE, 240-GRIT, or CoMat 05-198 ALUMINUM OXIDE, 320-GRIT to remove the scale. Keep the nozzle a distance of three to four inches (76 mm to 102 mm) from the part at an angle of 45 deg to 60 deg to the work surface.

   5. Blow with clean air at 30 psi (207 kPa) maximum to remove any remaining media.

   6. Visually examine the part for even cleaning and that no blasting media, masking, or water is remaining.

   7. Remove the masking.

   8. Apply corrosion inhibitor, as necessary, by SPM TASK 70-38-37-300-503.