Chemical Film (chem film) coatings are gelatinous films which provide some sort of a barrier medium to retard corrosion on aluminum surfaces and enhance adhesion of subsequent coatings such as paints and primers. Materials qualified produce coatings that range in color from clear to iridescent yellow or brown. They are electrically conductive to give some measure of corrosion protection. Inspection difficulties may arise with clear coatings because visual inspection does not always reveal the presence of a break in the coating.
Chem Film per Mil-DTL-5541 Type I and II, class I, II, and III.