![]() | COMMERCIAL ENGINE STANDARD PRACTICES MANUAL | Dated: 04/01/2014 |
SPM 70-43-29 APPLICATION OF AIR-DRIED MOLYBDENUM DISULFIDE DRY FILM LUBRICANTS | ||
TASK 70-43-29-380-001 |
1 . | General. |
A. | Dry film lubricant varnishes are Molybdenum Disulfide and other lubricants dispersed in an inorganic binder and nonflammable solvent. They are applied with either an aerosol can or a brush. These dry film lubricant varnishes cure at ambient temperatures and humidity. |
2 . | Equipment. |
A. | An efficient ventilation system to remove and neutralize vapors. |
B. | A clean cloth to clean and remove excess lubricant. |
3 . | Materials. |
NOTE: |
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4 . | Procedure. |
A. | Process a test coupon (a strip of flat sheet metal) along with the part to be dry-lubricant-coated. The test piece will be used for quality assurance purposes. |
B. | Measure the thickness of the test piece before you apply the lubricant if the process document specifies the thickness of an applied lubricant. |
WARNING: |
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C. | Clean the part and the test piece with a cloth saturated with a solvent listed in Step 3, Materials, unless otherwise stated in the process document. Apply the lubricant within 15 minutes. |
CAUTION: |
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D. | Apply masking to the part per the process document if specified. |
E. | Apply a dry film lubricant specified in Step 3.B. If you use an aerosol can to apply the lubricant, keep the spray nozzle approximately 8 inches (20 cm) from the surface of the part. |
F. | Make sure the coating thickness is approximately 0.0006-0.0012 inch (0.015-0.030 mm) unless specified differently in the process document. If the lubricant must dry between coats, allow 10-30 minutes of drying time between each coat. |
CAUTION: |
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G. | Remove any overspray or excess lubricant with a clean cloth dampened with one of the solvents listed in Step 3, Materials. |
H. | Let the lubricant air cure at ambient temperature for the time specified by the lubricant manufacturer. |
I. | Measure the coating thickness if a thickness is specified in the process document. Apply more layers of lubricant as necessary and air dry between coats. |
J. | Remove the masking, if applied. |
5 . | Quality Assurance. |
A. | Do one of these tests on the test coupon that was processed with the part: |
(1) | Test with pressure sensitive tape: |
(a) | Apply a strip of pressure sensitive tape C10-189 to the test piece. Press the tape firmly to the piece. |
(b) | Pull off the tape. |
(c) | The coating shall not be lifted to expose any bare metal surface but a uniform deposit of powdery material clinging to the tape is acceptable. |
(2) | Test by scratching: |
(a) | Scratch the coating on the test piece with your fingernail. |
(b) | The coating shall not be lifted to expose any bare metal surface but uniform deposit of powdery material at the fingernail is acceptable. |
B. | Examine the coating on the processed part. It should have no sags, blisters, flakes, and foreign material. The coating should be smooth, uniform, and dark grey in color. |
C. | Remove the coating and reprocess the part if the coating fails any of these tests or examinations. |