Preliminary Requirements

Safety Requirements

WARNING

A SATISFACTORY FUME EXTRACTOR IS NECESSARY WHERE THE PARTS ARE SPRAYED.

WARNING

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

Procedure

1. SUBTASK 70-38-20-380-001 General Procedures to Apply the Coating

   1. Prepare the part.

      1. Use the subsequent procedure for aluminium alloy parts:

         1. Remove grease and oil from the part. Refer to SPM TASK 70-11-03-300-503.

         2. NOTE

            If you do not obey the procedure to remove the remaining abrasive particles in SPM TASK 70-12-01-120-501, the remaining abrasive particles could cause engine damage.

            Wet abrasive blast the part as specified in SPM TASK 70-12-01-120-501 with CoMat 05-003 ABRASIVE MEDIUM ALUMINUM OXIDE, 120/220 GRADE. Alternatively, dry abrasive blast the part as specified in SPM TASK 70-12-02-120-501 with CoMat 05-003 ABRASIVE MEDIUM ALUMINUM OXIDE, 120/220 GRADE.

         3. Apply a chromate conversion coating (refer to SPM TASK 70-38-02-300-503), or chromic acid anodize (refer to SPM TASK 70-33-20-300-503), as specified in the Engine Manual.

         4. Stop-off the areas that are not to be painted with blanks, plugs, or tape. Refer to SPM TASK 70-38-24-300-503.

      2. Use the subsequent procedure for steel parts:

         1. Remove grease and oil from the part. Refer to SPM TASK 70-11-03-300-503.

         2. NOTE

            If you do not obey the procedure to remove the remaining abrasive particles in SPM TASK 70-12-01-120-501, the remaining abrasive particles could cause engine damage.

            Dry abrasive blast the part as specified in SPM TASK 70-12-01-120-501, with CoMat 05-003 ABRASIVE MEDIUM ALUMINUM OXIDE, 120/220 GRADE.

         3. Stop-off the areas that are not to be painted. Use blanks, plugs, or tape. Refer to SPM TASK 70-38-24-300-503.

   2. Mix the coating material.

      1. Refer to the manufacturer's instructions to mix the CoMat 07-063 HEAT RESISTING EROSION RESISTANT COATING, EPOXY SILICONE. If there are solid particles in the mixed coating material, put the coating material through a 300 mesh (BS 410, 53 microns aperture) sieve to before you apply the coating material.

   3. Apply the coating material.

      1. NOTE

         The spraying conditions that follow will usually give a coating thickness of 0.001 in. to 0.002 in. (0.025 mm to 0.05 mm).

         NOTE

         It is necessary to do inspections at regular intervals to make sure that the coating thickness is correct.

         Apply the CoMat 07-063 HEAT RESISTING EROSION RESISTANT COATING, EPOXY SILICONE by spraying or by brushing.

         1. Apply one coating layer to the part, then let the applied coating layer dry in ambient air (16 deg C (61 deg F) minimum) for approximately three minutes, or as specified by the coating compound manufacturer, to let the solvent in the compound dry before you apply the second coating layer.

         2. NOTE

            It is typical to dry the second coat in ambient air (16 deg C (61 deg F) minimum) for approximately 30 minutes.

            Apply a second coating layer to the part, then let the applied coating layer dry in air to the coating compound manufacturer's instructions to let the solvent in the compound dry.

         3. NOTE

            When masking tape is used, it must be removed before stoving.

            NOTE

            It is important to keep the parts at the correct stoving temperature for the time specified.

            NOTE

            Typical stoving is 185 deg C to 195 deg C (365 deg F to 383 deg F) for two hours minimum.

            Stove the part in accordance with the coating material manufacturer's instructions.

      2. Examine the coating. It must be smooth and equally applied to the full area, with no runs, drops, tears, blisters, or other defects. Also, there must not be too much coating applied to the part edges (for example, compressor leading and trailing edges).

         1. If the coating layer shows local damage, use the Step procedure to repair the damage.

2. SUBTASK 70-38-20-380-002 Procedures to Apply the Coating Locally

   1. Clean the part with a solvent cleaner, as specified in SPM TASK 70-11-26-300-503, then let them become dry.

   2. Apply masking as necessary.

   3. Rub the damaged area with CoMat 05-021 WATERPROOF SILICON CARBIDE or CoMat 05-020 WATERPROOF SILICON CARBIDE until it is smooth with the adjacent surface.

   4. Clean the part with a solvent cleaner as specified in SPM TASK 70-11-26-300-503, then let the part become dry.

   5. Use a brush to apply a chromate conversion coating to aluminum parts as specified in SPM TASK 70-38-02-300-503.

   6. Remove and replace all of the masking.

   7. Apply the coating material.

      1. NOTE

         The necessary color will be specified in the Engine Manual.

         Where possible, apply the CoMat 07-063 HEAT RESISTING EROSION RESISTANT COATING, EPOXY SILICONE to the damaged area as specified in the apply the coating material instructions in Step.

      2. If it is not possible to stove the part again, first apply a coating of CoMat 07-080 TWO-PACK EPOXY PRIMER AND CATALYST then a coating of CoMat 07-007 TWO-PACK EPOXY FINISH (WHITE) AND CATALYST or CoMat 07-062 TWO-PACK EPOXY FINISH, GREY, AIRCRAFT, BS381C 693.