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 MATERIAL 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.

CAUTION

THIS PROCESS MUST ONLY BE USED WHEN SPECIFIED IN THE APPLICABLE ENGINE MANUAL. REFER TO THE APPLICABLE CLEANING TASK FOR THE PARAMETERS. ALTERNATIVE SOLUTIONS ARE NOT PERMITTED.

CAUTION

IAE RECOMMENDS THE SOLUTIONS ARE USED AT AMBIENT TEMPERATURES BETWEEN 64 F AND 73 F (18 C AND 23 C), IF USED AT A GREATER TEMPERATURE, THE ETCH TIME MUST BE REDUCED.

Procedure

1. SUBTASK 70-11-08-300-001 Solvent Clean the Part

   1. If it is specified to activate the surface that you will etch, lightly abrade the surface with one of the materials in the subsequent list:

      1. CoMat 05-020 WATERPROOF SILICON CARBIDE.

      2. CoMat 05-021 WATERPROOF SILICON CARBIDE.

      3. CoMat 05-078 WATERPROOF SILICON CARBIDE.

      4. CoMat 05-129 ALUMINUM OXIDE ABRASIVEPAPER.

   2. Make sure the part is at ambient temperature.

   3. Clean the part as given in SPM TASK 70-11-14-300-503.

2. SUBTASK 70-11-08-300-002 Swab Etch the Part

   1. Put sufficient hydrofluoric acid/nitric acid etch solution for the work into an applicable open polythene container. Refer to SPM TASK 70-11-08-100-501 for the hydrofluoric acid/nitric acid etch solution make-up. Discard the etch solution after use and fully clean the container in clean, cold water.

   2. Hold a cotton wool swab in chemical resistant tongs or tweezers. Dip the cotton wool swab in to the hydrofluoric acid/nitric acid etch solution. Push swab lightly against the container side to remove unwanted solution.

   3. Swab the necessary area of the part with the cotton wool pad. Do not let the hydrofluoric acid/nitric acid etch solution go on other areas. Keep a layer of the hydrofluoric acid/nitric acid etch solution on the surface for the specified etch time. If no etch time is specified, keep a layer of the hydrofluoric acid/nitric acid etch solution on the surface for approximately 20 to 30 seconds until you can see a gray surface.

   4. Immediately swab fully the part with clean, cold water. Do this step again with clean swabs until the hydrofluoric acid/nitric acid etch solution is fully removed.

   5. If there is smut on the etched surface, swab with hydrofluoric acid/nitric acid desmutting solution to remove the smut. Refer to SPM TASK 70-11-08-100-501 for the hydrofluoric acid/nitric acid desmutting solution make-up.

   6. Swab the surface with the titanium etch neutralizing solution to neutralize the acid. Refer to SPM TASK 70-11-08-100-501 for the titanium etch neutralizing solution make-up.

   7. Swab the part with clean, cold water. Do this step again with clean swabs until the titanium etch neutralizing solution is fully removed.

   8. Swab wash the part with CoMat 01-031 ACETONE (CH3)2CO to remove the water, then let the part dry.

   9. Examine the area where etch is specified. If the surface in the area did not turn matt gray, do the subsequent procedure:

      1. Lightly abrade the area with one of the materials in the subsequent list to re-activate the surface:

         1. CoMat 05-020 WATERPROOF SILICON CARBIDE.

         2. CoMat 05-021 WATERPROOF SILICON CARBIDE.

         3. CoMat 05-078 WATERPROOF SILICON CARBIDE.

         4. CoMat 05-129 ALUMINUM OXIDE ABRASIVEPAPER.

      2. Do Step procedure again to etch the surface.