Preliminary Requirements

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS 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

DO NOT USE THIS METHOD ON COPPER BRAZED AND LEAD-BASE SOLDERED PARTS.

CAUTION

DO NOT USE THIS METHOD TO STRIP COATINGS FROM ANY CAST MATERIAL, ESPECIALLY TURBINE VANES, EXCEPT WHERE PERMITTED BY SPECIFIC REPAIR INSTRUCTIONS.

CAUTION

DO NOT USE THIS METHOD ON ELECTROPLATED PARTS.

CAUTION

IF STRIPPING SOLUTION IS INADVERTENTLY EXPOSED TO CHROMIUM PLATED PARTS, THE SOLUTION MUST BE REPLACED.

Procedure

1. SUBTASK 70-33-78-300-001 Hold the Part

   1. 

      CAUTION

      ELECTRICAL CONTACT MUST BE MADE IN THE LOCATION SPECIFIED BY IAE SO AS TO PREVENT ARCING, BURNING, PITTING, OR SELECTIVE ATTACK ON THE PART.

      

      CAUTION

      FOR TITANIUM PARTS, CONTACT AREAS OF THE FIXTURE OR CLAMPING DEVICES MUST BE MADE OF TITANIUM (AMS 4900 OR EQUIVALENT). ALL OTHER CLAMPING, HOLDING, AND DETAILS THAT CARRY CURRENT MUST BE MADE OF TITANIUM OR BE COVERED WITH SUITABLE INSULATING RACK COATINGS.

      Assemble the part in a suitable fixture or clamping device.

2. SUBTASK 70-33-78-300-002 Remove the Grease

   1. Degrease, if necessary. (Refer to the SPM TASK 70-11-03-300-503.)

3. SUBTASK 70-33-78-300-003 Remove the Plasma or Flame Plate Coating

   1. 

      CAUTION

      DO NOT EXCEED 6 VOLTS DC OR SPECIFIED STRIPPING TIME.

      

      CAUTION

      TITANIUM PARTS MUST BE FULLY IN THE STRIPPING SOLUTION BEFORE THE CURRENT FLOWS. THIS WILL PREVENT SEVERE PITTING AT THE AIR-SOLUTION INTERFACE.

      NOTE

      The solution must be moderately shaken (agitated). It is permitted to use either the steel tank or mild steel cathodes.

      Put the part fully into sodium carbonate-tartrate stripping solution (Solution Code 102) (refer to the SPM TASK 70-33-78-100-501.) at a temperature of 140 to 160 deg F (60 to 71 deg C) for a maximum of 30 minutes. Current must be OFF as the parts go in or out of the solution. Make the part anodic. Slowly raise the potential to the 5 to 6 volt range.

   2. Flush the part fully with clean water at room temperature for 30 seconds.

   3. Compressed air/water spray rinse with shop air and water for 30 to 60 seconds at room temperature.

   4. Examine the parts for removal of the coating. If necessary, do steps A. thru C. again until the coating has been stripped, or for a maximum of eight cycles.

   5. Dry the parts fully with shop air.

   6. 

      CAUTION

      BE ESPECIALLY CAREFUL NOT TO DWELL TOO LONG WHEN GRIT BLASTING AREAS THAT DO NOT HAVE ANY COATING.

      NOTE

      It is permitted to use No. 90 grit as an alternative grit to those specified in the above referenced procedure. The grits that follow can be used: CoMat 05-035 ALUMINUM OXIDE ABRASIVE, or CoMat 05-036 DELETED, or CoMat 05-037 DELETED.

      If the coating has only been degraded, grit blast the coated areas to fully remove any remaining coating. (Refer to the SPM TASK 70-34-03-340-501, SUBTASK 70-34-03-380-001).

   7. 

      CAUTION

      YOU MUST USE A WIRE BRUSH WHICH HAS BRISTLES OF AUSTENITIC CORROSION RESISTANT STEEL.

      If necessary, remove any remaining coating with a tampico or wire brush.

4. SUBTASK 70-33-78-300-004 Preserve the Parts

   1. Preserve the parts in a corrosion preventative, as necessary. (Refer to TASK 70-38-05-300-503).