Zinc Chromate Finish

Chromate conversion coating or alodine coating is a type of conversion coating used to passivate steel aluminium zinc cadmium copper silver titanium magnesium and tin alloys.

Zinc chromate finish.

Wash primers especially the acid activated type are considered pretreatments and should only be applied directly to bare metal. The zinc chromate pretreatment is a perfect pre paint treatment for aluminum. Zinc trivalent chromate plating. Zinc chromate zn cr o 4 is a chemical compound containing the chromate anion appearing as odorless yellow powder or yellow green crystals but when used for coatings pigments are often added.

There is no real difference between a zinc finish and a zinc chromate finish because although there are now some chromate free topcoats zinc plating is always top coated. Most commonly steel aluminum zinc cadmium copper silver magnesium and tin alloys benefit from this process. Great lakes metal finishing is experienced in effectively using both trivalent chromate otherwise known as trivalent passivation and hexavalent chromium. Back in the 1940s as well as in the paint industry of today the term zinc chromate does not refer to a paint color but rather a protective coating.

The yellow chromate is a yellow bronze iridescent finish on plated cadmium and zinc. To improve those older zinc pot metal castings plate with a fresh zinc plate before chromating. P 1265 the coating serves as a corrosion inhibitor as a primer to improve the adherence of paints and adhesives as a decorative finish or to preserve electrical conductivity. Glmf still processes many parts with hexavalent chromium but we have seen a push to use trivalent passivates on zinc plated parts.

Chromate conversion is a type of conversion coating used to passivate a number of alloys. The zinc the chromate react to form the new colors. Even today chromate finishes including zinc chromate provide superior corrosion resistance. Blue chromate our blue chromate concentrate produces a true blue conversion coating on zinc plated items.

Liquid concentrate is used at 0 5 to 3 by volume in water at 65 to 90 f. It is a single dip blue trivalent chromate that offers high salt spray resistance for up to 130 hours to white rust corrosion and. There s no need for a wash primer. Chromate is a top coat that is put on zinc plated items to deter the zinc from white rusting.

Degrease the zinc chromate to remove oily soils and paint over it.