Columbia Chemical’s Zinc-Chro-SHIELD and Lac-Chro-SEAL topcoats are economical to use and work well on top of  COLDIP chromate conversion coatings.

Zinc-Chro-SHIELD - produces an extremely thin coating which extends corrosion resistance to blue and yellow (hexavalent & trivalent) chromated zinc deposits by 3 to 5 times.  Economical and easy to use, simply add to final, stagnant rinse tank at 2 - 7% by volume. 

Zinc-Chro-SHIELD AFTERBLACK 200 - greatly improves corrosion resistance on silver black hexavalent chromate conversion coatings, while retaining desired glossy, black appearance.  Produces results similar to expensive black zinc-alloy systems without the cost and trouble. 

Lac-Chro-SEAL - non-solvent lacquer suitable for use over any chromated zinc deposit.  Prevents fingerprints and improves corrosion resistance.  Economical and safe to use; strips easily in standard alkaline soak cleaners.