Preliminary Requirements

Procedure

1. SUBTASK 72-32-91-350-060 Remove the Damaged Vane

   1. Refer to Figure and Figure.

   2. 
      CAUTION
      BE CAREFUL NOT TO DAMAGE THE SURFACE OF VANE AND RING WHEN REMOVING MOLDING RUBBER.

      Remove the molding rubber to break the connection between vane and inner ring. Remove the damaged vane from the inner ring.

      1. Use a clean plastic chisel type tool.

   3. Remove the molding rubber from AREA A.

      1. Use a clean plastic chisel type tool.

         1. If necessary, use CoMat 05-019 WATERPROOF SILICON CARBIDE and CoMat 05-020 WATERPROOF SILICON CARBIDE.

   4. Remove the remaining molding rubber from the removed vane if the vane is serviceable. Refer to Repair, VRS1776 TASK 72-32-91-300-012 (REPAIR-012).

      NOTE

      If it is necessary to replace the abradable seal rubber on the inner ring, remove the rubber after the vanes have been removed. The new rubber should be put back and cured after the new vanes have been attached and bonded.

      If it is not necessary to repair the rubber, put on a shield to prevent damage to the rubber during this repair.

      1. Use a clean plastic chisel type tool.

   5. Remove the remaining molding rubber from AREA A and/or the removed vane, if the remaining rubber is not fully removed in Step or Step.

      1. Apply adhesive tape for masking to the areas which do not require removing the remaining rubber.

         1. Use CoMat 02-001 ADHESIVE TAPE (MASKING) or CoMat 02-005 ADHESIVE TAPE (MASKING).

      2. Use dry plastic blast to remove the remaining rubber.

         1. Refer to SPM TASK 70-12-07-120-501.

      3. Remove adhesive tape for masking.

2. SUBTASK 72-32-91-120-059-001 Prepare the Bonding Area

   1. NOTE

      This SUBTASK is an alternative to Step.

      Apply masking tape to the areas which do not require the molding compound.

      1. Use CoMat 02-001 ADHESIVE TAPE (MASKING) or CoMat 02-005 ADHESIVE TAPE (MASKING).

   2. Apply dry abrasive blast to the bonding Area.

      1. Use CoMat 05-121 SILICON CARBIDE GRIT, CoMat 05-122 SILICON CARBIDE GRIT, CoMat 05-123 SILICON CARBIDE GRIT and CoMat 05-124 SILICON CARBIDE GRIT.

         1. Refer to SPM TASK 70-36-04-360-501.

   3. Remove remaining abrasive by vacuuming or clean air blow.

      1. Use a vacuum cleaner.

3. SUBTASK 72-32-91-120-059-002 Prepare the Bonding Area

   1. NOTE

      This SUBTASK is an alternative to Step.

      Prepare the bonding area.

      1. Use CoMat 05-084 WATERPROOF SILICON CARBIDE and CoMat 05-085 WATERPROOF SILICON CARBIDE.

4. SUBTASK 72-32-91-110-058 Clean the Bonding Area

   1. Refer to Figure, Figure and Figure.

   2. Clean the bonding area of the vane and the inner ring.

      1. Use CoMat 02-099 LINT-FREE CLOTH with CoMat 01-124 ISOPROPYL ALCOHOL.

   3. NOTE

      After cleaning the component must not be touched by hand and must be covered by craft paper to prevent contamination.

      Air dry for 15 minutes minimum.

5. SUBTASK 72-32-91-360-065 Apply the Primer to the Bonding Area

   1. Refer to Figure, Figure and Figure.

   2. 
      CAUTION
      THE PRIMER MUST NOT BE APPLIED TO THE SILICONE RUBBER. THE PRIMER MUST BE APPLIED TO THE METAL SURFACE ONLY.

      NOTE

      The primer must be applied within eight hours after the bonding area is prepared.

      NOTE

      Let the primer dry at a room temperature of 77 deg F (25 deg C) for two hours minimum, 24 hours maximum at a moisture level equivalent to 50 percent minimum relative humidity.

      NOTE

      Parts must have the silicone rubber compound applied within 24 hours of completion of primer application.

      Apply a thin layer of the primer to the bonding area.

      1. Use CoMat 08-032 PRIMER.

6. SUBTASK 72-32-91-360-066 Make-up the Silicone Rubber Compound

   1. Mix 9.5 to 10.5 parts by weight of the base material with 0.8 to 1.2 parts by weight of the curing agent in 8 to 10 minutes at 70 to 80 deg F (21 to 27 deg C) until the material is a constant color.

      1. Use CoMat 08-042 SILICONE RUBBER COMPOUND, a clean spatula and a mass weighing scale.

   2. NOTE

      When mixed, the life of the silicone rubber compound is a maximum of 1.5 hours at room temperature.

      Remove all the air from the mixture at 28 in. (711.2 mm) mercury vacuum for 15 minutes minimum.

      1. Use a vacuum pump.

7. SUBTASK 72-32-91-360-067 Apply and Cure the Silicone Rubber Compound

   1. Refer to Figure, Figure and Figure.

   2. Set up the mold with the molding fixture and install the new or serviceable vane in position.

      1. Use IAE 3J12137 Molding fixture 1 off or IAE 3J12829 Molding Fixture 1 off.

   3. Apply the silicone rubber compound to the bonding area (AREA A).

      1. Use an air pressure type injector.

   4. Cure the silicone rubber compound at room temperature for 16 hours followed by being kept at 290 and 310 deg F (143 and 153 deg C) for 2 hours with the molding fixture attached.

   5. Remove the LPC inlet guide vane assembly from the molding fixture.

8. SUBTASK 72-32-91-350-061 Complete the Repaired Areas

   1. Refer to Figure, Figure and Figure.

   2. Complete the repaired areas to the limit given in the figure.

      1. NOTE

         This process can be done before the rubber is cured completely.

         The repaired areas must be the same as the adjacent area.

         1. Use a clean plastic chisel type tool.

9. SUBTASK 72-32-91-220-084 Examine the Repaired Areas

   1. Refer to Figure, Figure and Figure.

   2. Dimensionally and visually examine the repaired area.

10. SUBTASK 72-32-91-380-059 Apply Surface Protection to the Inner Ring

    1. Refer to Figure.

    2. Burnish the area where the parent material is exposed.

       1. Use CoMat 05-125 ABRASIVE PAD, SILICON CARBIDE, ULTRA-FINE and CoMat 05-126 ABRASIVE PAD, ALUMINUM OXIDE, VERY FINE.

    3. Apply chromate conversion coating to the area.

       1. Use CoMat 01-275 CHROMATE CONVERSION COATING FOR ALUMINIUM.

          1. Refer to the SPM TASK 70-38-02-300-503.

Figure: Repair Details and Dimensions

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Repair Details and Dimensions

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Figure: Repair Details and Dimensions

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Figure: Repair Details and Dimensions

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Repair Details and Dimensions

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