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.

WARNING

ALL EQUIPMENT USED IN THE PAINT SHOP AREA MUST BE FLAMEPROOF.

AN EFFECTIVE FUME REMOVAL SYSTEM MUST BE USED.

OVENS USED FOR STOVING MUST BE SUFFICIENTLY VENTILATED, WASTE GASES FROM THE OVEN HEATING SYSTEM MUST BE REMOVED FROM THE OVEN.

VAPOR DEGREASING PLANT AND WET PROCESSING TANKS MUST BE SUFFICIENTLY SCREENED TO PREVENT CONTAMINATION.

WARNING

THE PAINT MATERIALS ALL HAVE LOW FLASH POINTS, (SOME BELOW 73 DEG F (22.8 DEG C)) AND, THUS, ARE HIGHLY FLAMMABLE.

ALL PERSONNEL MUST TAKE NORMAL PRECAUTIONS TO PREVENT THE EPOXY TYPE MATERIALS FROM TOUCHING THE SKIN.

WARNING

RECOMMENDED BARRIER CREAM MUST BE APPLIED TO THE HANDS AND FOREARMS BEFORE STARTING WORK.

GLOVES MUST BE WORN.

HAND CONDITIONING CREAM MUST BE APPLIED AFTER WORK.

ACCIDENTAL PAINT SPLASHES MUST BE IMMEDIATELY CLEANED FROM THE SKIN WITH RESIN REMOVING CREAM AND SUBSEQUENT WASHING.

YOU MUST GET IMMEDIATE MEDICAL ATTENTION IF YOU GET SPLASHED IN THE EYE.

Procedure

1. SUBTASK 70-38-34-300-001 Processing - General Application

   1. Prepare the parts.

      1. The parts must be pre-treated according to their base material as follows:

         1. Chromated magnesium parts must be oven dried for 1 hour at 250 to 300 deg F (120 to 150 deg C).

         2. Aluminum parts must be annodised, refer to the SPM TASK 70-33-20-100-501, or alocrom treated, refer to the SPM TASK 70-38-02-100-501, and oven dried for 1 hour at 250 to 300 deg F (120 to 150 deg C).

         3. Steel parts must be abrasive blasted, refer to the SPM TASK 70-12-01-120-501. After processing, parts can be oven dried for 1 hour at 250 to 300 deg F (120 to 150 deg C).

      2. Vapour degrease the parts, refer to the SPM TASK 70-11-01-100-501.

      3. Stop off the areas which are to be left unvarnished with correct blanking plates, plugs and CoMat 02-019 TAPE, ADHESIVE PAPER HEAT RESISTING MASKING.

         NOTE

         Obey the viscosity requirements in SUBTASK 70-38-34-100-001.

   2. Apply the primer.

      1. NOTE

         On close tolerance surfaces, spray one coat of primer to give a minimum dry film thickness of 0.0005in. (0.0127 mm) and allow to dry for 15 to 20 minutes.

         On surfaces where no large thickness of primer is permitted, spray one coat of primer and, using a clean solvent moistened lint-free cloth, wipe off the bulk of the primer.

         On general surfaces, spray one coat of primer and stand for 3 minutes.

      2. Spray another coat of primer to give a minimum dry film thickness of 0.001in. (0.025 mm) and air dry for 15 to 20 minutes.

      3. NOTE

         It is recommended to remove the masking tape before stoving at 385 deg F (195 deg C).

         On parts which are to be coated only with primer heat to 385 deg F (195 deg C) in the limits of 375 to 395 deg F (190 to 200 deg C) and maintain this temperature for 1 hour unless specially instructed differently in the Engine Manual.

      4. NOTE

         Where static ovens are used, the air drying time immediately before stoving is important. If conveyor ovens are used, the temperature increase is slow and continuous and air drying is not necessary.

         Where enamelling is to follow, stove the primer by heating the part to 300 deg F (150 deg C) within the limits of 290 to 310 deg F (145 to 155 deg C) and keep this temperature for 30 minutes.

   3. NOTE

      Obey the viscosity requirements in SUBTASK 70-38-34-100-001.

      Apply the enamel.

      1. Stop-off areas which are not to be enamelled, with applicable plates, plugs or CoMat 02-019 TAPE, ADHESIVE PAPER HEAT RESISTING MASKING.

      2. Spray one coat of CoMat 07-087 EPOXY ENAMEL GREY on to the part and allow it to stand for 3 minutes.

      3. NOTE

         When a static oven is used the air drying time must be obeyed. With a conveyer type oven, when the temperature increase is slow and continuous and the stoving cycle is longer, air drying is not necessary.

         Spray a second coat of CoMat 07-087 EPOXY ENAMEL GREY on to the part to give a minimum dry film thickness of 0.001in. (0.025 mm) and allow to air dry for 15 to 20 minutes.

      4. Where more coats are to be applied, stove the enamel by heating the part to 300 deg F (150 deg C) within the limits of 290 to 310 deg F (145 to 155 deg C) and keep this temperature for 30 minutes.

      5. Do steps (2) and (3) again until the specified thickness in step (8) has been obtained.

      6. Carefully remove any stop off tape.

      7. Stove final coat by heating the part to 385 deg F (195 deg C) within the limits of 375 to 395 deg F (190 to 200 deg C) for a time of 1 hour unless differently specified in the Engine Manual.

      8. The flim thickness is obtained by the control of paint viscosity and the application. Thickness checks can be made, using an approved measuring instrument. The film thickness necessary depends on the base material of the part as follows.

         1. On magnesium alloy parts the minimum film thickness of the total paint scheme is to be 0.004 in. (0.100 mm) on general surfaces.

         2. On aluminum and steel parts the minimum film thickness is to be 0.002 in. (0.005 mm) on general surfaces.

      9. Check that the coatings are evenly applied and continuous, giving complete coverage of the scheduled area. No runs, drops, tears, blisters or other imperfections are permitted.

      10. If the coating is frequently unsatisfactory, strip the paint as given in TASK 70-11-10-300-502 and apply the coating again. If local damage has occurred do the local application as detailed in Step.

2. SUBTASK 70-38-34-300-002 Processing - Local Application

   1. Rub down the paint surface immediately adjacent to the damaged area, feathering the edges of the paint, using an applicable grade of CoMat 05-020 WATERPROOF SILICON CARBIDE or CoMat 05-021 WATERPROOF SILICON CARBIDE which is given by the roughness of the surface.

   2. Take care not to damage the metal pre-treatment.

   3. NOTE

      Selenious acid treatment must not be used.

      Damaged chromate films on magnesium parts must be locally chromated as specified in the Engine Manual.

   4. Cold liquid degrease the prepared surface as given in the SPM TASK 70-11-14-300-503.

   5. Where possible touch up the damaged surfaces with CoMat 07-086 CHROMATE EPOXY PRIMER and/or CoMat 07-087 EPOXY ENAMEL GREY and stove again.

   6. When stoving again in not practicable, during or after assembly, touch-up the damaged surfaces as follows.

      1. Using a clean, good quality brush apply one coat of mixed CoMat 07-080 TWO-PACK EPOXY PRIMER AND CATALYST and CoMat 07-081 EPOXY PRIMER CATALYST prepared according to the SPM TASK 70-38-24-100-501 thinned as necessary with CoMat 07-082 THINNER.

      2. Allow to air dry for 4 hours at a minimum temperature of 60 deg F (16 deg C).

      3. Using a clean, good quality brush apply one coat of CoMat 07-062 TWO-PACK EPOXY FINISH, GREY, AIRCRAFT, BS381C 693 prepared according to the SPM TASK 70-38-34-100-501.

      4. Allow to air dry for 4 hours, the enamel is hard-dry after 6 hours.

      5. If necessary, apply a further coat of enamel.