Types. The chemical conversion materials are of the following types:
Type I – Compositions containing hexavalent chromium.
Type II – Compositions containing no hexavalent chromium.
Classes. The materials, which form protective coatings by chemical reaction with aluminum and aluminum alloys, are of the following classes:
Class 1A – For maximum protection against corrosion, painted or unpainted.
Class 3 – For protection against corrosion where low electrical resistance is required
Material forms. Chemical conversion materials are of the following forms:
Form I – Concentrated liquid
Form II – Powder
Form III – Premixed liquid (ready for use touch-up brush application)
Form IV – Premixed liquid, thixotropic (ready for use)
Form V – Premeasured powder, thixotropic (ready for use after addition of water)
Form VI – Premixed liquid (ready for touch-up use in self-contained applicator device)
Application methods. Chemical conversion materials are of the following application methods:
Method A – Spray
Method B – Brush-on or wipe-on
Method C – Immersion
Method D – Applicator pen or pre-saturated applicator device