Ask the Expert Question-and-Answer Archive

by Ron Joseph

May, 2003

Temperature Resistance of Zinc Chromate Paints

Q. What is the temperature rating for parts coated with a zinc chromate primer (no top coat). ie, the temp before the chromate will burn off.

A. Zinc chromate is a pigment and not a paint. The temperature at which it will burn off will depend on the resin of the paint resin you are using, such an alkyd, epoxy, polyurethane, etc. Usually these resins can withstand up to about 300oF. However, resins are available that can withstand higher temperatures. By the way, you also need to differentiate between exposure to constant high temperatures or sporadic short temperature spikes.