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 INFORMATION (SUCH AS HAZARDOUS INGREDIENTS; PHYSICAL/CHEMICAL CHARACTERISTICS; FIRE, EXPLOSION, REACTIVITY, AND HEALTH HAZARD DATA; PRECAUTIONS FOR SAFE HANDLING; USE AND CONTROL MEASURES), AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

1. SUBTASK 70-12-08-300-001 Wet Abrasive Blast 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

      IT IS NOT PERMITTED TO MIX THE VARIOUS BLASTING MEDIA UNLESS PERMITTED BY A PROCEDURE.

      

      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 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

      DO NOT USE SPM TASK 70-11-33-300-503 ON TITANIUM PARTS.

      

      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.

      Initially clean the part - (Refer to SPM TASK 70-11-01-300-503, SPM TASK 70-11-26-300-503 or SPM TASK 70-11-33-300-503).

   2. When necessary, apply a mask to the part so that the material can not become caught.

   3. Set the machine air pressure at 60 to 100 lb/sq in.

   4. 
      CAUTION
      DO NOT STOP IN ONE AREA FOR MORE THAN TWO SECONDS. USE A CONTINUOUS MOVEMENT.

      Blast with the wet abrasive compound - (Refer to SPM TASK 70-12-08-100-501), as necessary, to remove the unwanted material. Keep a 3 to 4 in. (75 to 100 mm) nozzle-to-part distance; at a 45 to 60 degree angle, to the work surface.

      1. Remove the masking, if used.

   5. Pressure flush with hot or cold water.

      1. Put part fully in hot water at 150-200 degrees F (66-93 degrees C) until the temperature of the part increases sufficiently to flash dry.

         1. If the water on the part surface does not flash off when the part comes out of the hot water, then the time interval that the part stayed in the hot water was too short to increase the part temperature sufficiently.

   6. Dry with compressed air at 30 psi (206.8 kpa) maximum to remove any remaining water.

   7. Remove the mask.

   8. Visually inspect the part to make sure all the blasting residue has been removed. Repeat as necessary to remove any residual residues.

   9. Apply corrosion inhibitor, as necessary. Refer to SPM TASK 70-38-05-380-501.