Heat Resistant Zinc 4285 Grey DESCRIPTION : A high loading of pure metallic zinc combined with a modified silicone resin provides outstanding corrosion control to steel surfaces through cathodic protection. USDA acceptable and Agriculture Canada approved. USES : Designed to be used as a two-coat system for exterior exposures subject to heat in the temperature range of 300 - 800°F (149 - 427°C), weathering and mild industrial conditions. This coating may also be used for interior surfaces. Must be applied to a clean, sandblasted surface.