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, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

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 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 THE 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

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

CAUTION

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

Procedure

1. SUBTASK 70-12-01-860-001 Equipment and Material

   1. Consumable materials

      CoMat 01-110 SODIUM BENZOATE C6H5COONa	Sodium benzoate (C6H5COONa)
      CoMat 01-111 SODIUM NITRITE NaNO2	Sodium nitrite (NaNO2)
      CoMat 05-001 ABRASIVE MEDIUM, ALUMINIUM OXIDE, 20/30 GRADE	Aluminum oxide 20 grade
      CoMat 05-002 ABRASIVE MEDIUM, ALUMINUM OXIDE	Aluminum oxide 60/80 grade
      CoMat 05-003 ABRASIVE MEDIUM ALUMINUM OXIDE, 120/220 GRADE	Aluminum oxide 120/220 mesh
      CoMat 05-004 ABRASIVE MEDIUM, ALUMINUM OXIDE, 140/400 GRADE	Aluminum oxide 140/400 mesh
      CoMat 05-015 ABRASIVE MEDIUM, ALUMINUM OXIDE	Aluminum oxide 54 grade
      CoMat 05-022 ALUMINUM OXIDE ABRASIVE	Aluminum oxide 240 abrasive
      CoMat 05-035 ALUMINUM OXIDE ABRASIVE	Aluminum oxide abrasive No 90
      CoMat 05-041 ALUMINUM OXIDE GRIT	Aluminum oxide abrasive No 24
      CoMat 05-046 ALUMINUM OXIDE GRIT	Aluminum oxide abrasive No 60
      CoMat 05-068 DELETED	Aluminum oxide sieve 75-45
      CoMat 05-155 ALUMUNUM OXIDE ABRASIVE,27 MICRON	Aluminum oxide abrasive 27 micron
      CoMat 05-156 ALUMINUM OXIDE ABRASIVE	Aluminum oxide abrasive 500 grit
      CoMat 05-161 DELETED	Aluminum oxide abrasive 60 grit
      CoMat 05-164 DELETED	Aluminum oxide abrasive 46 grade
      CoMat 05-192 ALUMINUM OXIDE GRIT	Aluminum oxide abrasive No 60
      CoMat 05-193 ALUMINUM OXIDE, 90-GRIT	Aluminum oxide abrasive No 90
      CoMat 05-194 ALUMINUM OXIDE, 120- GRIT	Aluminum oxide abrasive No 120
      CoMat 05-195 ALUMINUM OXIDE, 150-GRIT	Aluminum oxide abrasive No 150
      CoMat 05-196 ALUMINUM OXIDE, 180-GRIT	Aluminum oxide abrasive No 180
      CoMat 05-197 ALUMINUM OXIDE, 240-GRIT	Aluminum oxide abrasive No 240
      CoMat 05-198 ALUMINUM OXIDE, 320-GRIT	Aluminum oxide abrasive No 320
      CoMat 05-199 ALUMINUM OXIDE, F500 GRIT	Aluminum oxide abrasive No 500
      CoMat 05-230 ABRASIVE MEDIUM ALUMINUM OXIDE, 280/500 GRADE	Aluminum oxide abrasive 280/500
      NOTE To identify the consumable materials refer to the PCI.

2. SUBTASK 70-12-01-120-001 Make-up and Control of Non-Metallic Abrasives

   
   CAUTION
   THE ABRASIVE GRITS MUST BE LEAD-FREE VIRGIN FUSED ALUMINA. CONTAINING LESS THAN 5 P.P.M. ELEMENTAL LEAD AND LESS THAN 20 P.P.M. TOTAL LEAD COMPOUNDS, WITH IRON CONTENT AS ACID EXTRACTABLE IRON NOT GREATER THAN ONE PERCENT. SEE EXAMPLES OF COMPOUNDS BELOW:

   1. Examples of virgin fused alumina compounds.

      Aluminum oxide (Al2O3) 99.3 percent minimum.

      Silicone dioxide (SiO2) 0.02 percent maximum.

      Titanium dioxide (TiO2) 0.01 percent maximum.

      Chromium oxide (Cr2O3) 0.25 percent maximum.

      Calcium oxide (CaO) 0.02 percent maximum.

      Magnesium oxide (MgO) 0.01 percent maximum.

      Iron oxide (FeO) 0.25 percent maximum.

      Alkali metal, sodium and potassium 0.25 percent maximum.

   2. The abrasive content must be more than 20 percent by volume and the fines less than 20 percent of the total solid content. The mixture must be replaced when these proportions are decreased or increased or when the sharp corners of the abrasive are removed.

   3. Examine the wet abrasive mixture as follows:

      1. Collect a sample from the nozzle, with the air shut off.

         NOTE

         When the abrasive is to be replaced in wet cabinets, the cabinet internals must be fully cleaned in clean water. The pump must then be filled with clean water and new abrasive added.

      2. Permit the sample to go to the bottom of a graduated tube. This will show the quantity of the proportions of abrasive, fines and water.

         NOTE

         Lead contamination can be made easier to see if the test panel is lightly stained with water which is at a temperature of 212 deg F (100 deg C).

   4. Spray a ferrous test panel to make sure there is no lead contamination. Contamination will show bonded particles or lead stains.

3. SUBTASK 70-12-01-120-002 The Procedure to Use Wet Abrasive or Vapor Blasting on a Component

   
   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.

   1. Clean the components to remove the grease and dirt as given in the Engine Manual.

   2. Seal all the areas that are not to be blasted.

   3. Put the components on to the platform in the blasting cabinet or hold in a gloved hand.

      NOTE

      The air pressure and times given are for usual conditions, these must be used unless the Engine Manual gives differently.

      The air used must have no oil in it and a satisfactory oil trap must be included in the system.

   4. Point the blast systematically on to the surface to be blasted for a minimum time necessary to clean the component. Blast the part using a pressure of 40 to 80 psi (280 to 560 KPa), depending on the part being cleaned. The pressure used must be appropriate to the geometry of the component.

4. SUBTASK 70-12-01-120-003 The Procedure After Wet Abrasive or Vapor Blasting a Component

   1. Clean the components fully in a flow of clean cold water immediately after it is blasted.

      NOTE

      A recommended inhibitor for the cold and hot water is a 2 to 1 mixture of CoMat 01-110 SODIUM BENZOATE C6H5COONa and CoMat 01-111 SODIUM NITRITE NaNO2. This mixture is added at a concentration of 1.6 oz/gal (12.5 g/l).

   2. Remove all the seals from areas that were not blasted. Clean the component again in inhibited cold water and inhibited hot water (minimum temperature 176 deg F, 80 deg C) then dry with dry air at pressure.

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

      NOTE

      When it is not necessary to do more procedures or protective treatment on a steel component, it must have temporary protection as referred to in the SPM TASK 70-38-05-380-501.

   4. Alternatively, the components can be cleaned with an air gun then put fully in to an approved dewatering oil, refer to the SPM TASK 70-38-05-380-501.