MIL-STD-186F (MI)
Remove the tape in one abrupt motion and examine the tested area for any paint damage, such as removal of paint at one of the layers of the finish system removal of the entire system from the metal. Test panels shall be sprayed with the complete finish, along with production items, and scratch wet tape adhesion tests in accordance with method 6301.2 of FED-STD-141 shall be conducted on these
panels after a 24-hour soaking period in distilled water. The test will be conducted immediately after removal from the water. Suitable adjustments shall be made in the materials and processes, based on the results of these tests. Production items shall be stripped and repainted if adhesive failure is judged by the procuring activity to be severe.
5.6.5 Film thickness. Contractors, inspectors and painters shall exercise constant diligence to maintain careful control of the thickness of paint finish during the production process to insure continual adherence to the established single coat thickness limits as specified in 5.5.4.6. Inspectors shall conduct regular and frequent paint thickness measurements on the production parts or panels with a suitable measuring device on a sufficient number of selected areas to assure thickness requirements for the individual paints and the overall thickness. At the start of production, the painter shall spray test panels as prescribed in 5.5.4.2. The thickness of the paint should then be measured on the panels with a micrometer or an Ames thickness gauge or equivalent, allowing 0.0001 to 0.0002 inch for further contraction in thickness to be expected during the drying of the paint. If the film thickness exceeds the allowable maximum, as specified above, necessary adjustments shall be made of the spray gun, paint viscosity, etc., and the trial spraying repeated until proper thickness is obtained. Then the painter may proceed with painting.
5.6.6 Dry film thickness. The upper limits on film thickness are not mandatory for surface areas on which such limits are impractical to maintain; for example, contoured areas. However, film thickness should be controlled in these areas, to prevent excessive deposition of paint. Film thickness tests shall be performed on uniform coated surfaces. Thickness testing shall be performed using a conventional nondestructive measuring device such as a magnetic tester in accordance with ASTM B 499, an eddy current tester in accordance with ASTM
B244, or other acceptable standard methods. Recommended thickness requirements for CARC primers and topcoats are listed in table XI; however, the upper limits may be exceeded as long as remaining quality assurance provisions are met. Be aware that previously applied coatings to the test area must be identified prior to topcoating, such as repair or rework areas. These previous coatings must
be measured and recorded in sequence to accommodate each progressive coating thickness determination. Unless otherwise specified, rejection will not be made based on the recommendations of table XI, but on subsequent performance failure of any another quality assurance provision.
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