Procedure No. AT 101-C Rev. 7 FAA Date: 10/16/01 APPROVED Original Issue Date: Sept. 19, 1989 PROCEDURE HIGH SOLIDS FINISH COLOR COAT – CHSM THIS PROCEDURE APPLIES TO THE HIGH SOLIDS COLOR SYSTEM ONLY!!! When you reach the color coat you are near the end of your project. Resist every temptation to hurry up and the job should turn out as you desire. There are a few precautions to remind you of at this point. The primer coat is porous by design and it must be fully cured before application of the top coat. If it is not the color will “bite in” too much and the high gloss can be lost. Let the primer cure 2-3 days at 70 F to ensure it is fully cured.
Remember, if the shop cools down at night it may not have an adequate cure temperature. Curing really slows below 50 F. Also, it is very important to ventilate the interior cavities of solvent vapors as mentioned on previous pages. Unlike metal or a hard surface the first coat of primer evaporates both inside the part and outside. These vapors must be removed for the primer to cure successfully. Sand the primer as necessary to provide a smooth surface for painting. Keep in mind that if more than 5 days elapse after priming the surface must be sanding for adhesion. The water based PFUW primer must be scuff sanded prior to painting.
Shake the color thoroughly to ensure uniform pigment dispersion. Manual mixing is not adequate. The first step in color coating or painting is to seal the fully cured primer coat. The most common option is to paint one coat of color on the primer. The color coat should be allowed to cure for 4 days at 70 F. It is most important for this coat to cure enough so that subsequent coats stand up and do not penetrate. However, the cured coat must be sanded with 320 or 400 grit sandpaper (wet or dry) before painting in order to achieve mechanical adhesion. This yields the “wet look” everyone looks for. The mix ratios for the color coat are as follows:
3 part Air-Tech CHSM color 1 part CCHSM 5071 catalyst up to Ѕ part Reducer thinner (4070 Rev. 4– cool weather; 4085 Rev. 4 warm weather) Reducer can be varied to suit. Add recommended amount of Accelerator Paint between 70F and 95F.