Product Description: 3X Chemistry Rust Blocker Undercoat, Qt. Clear Durable Coating Withstands Temp Up to 400ºF. Rust Blocker Undercoat is a clear high performance durable coating that protects all metal, fiberglass, concrete and wood surfaces from rust and corrosion. Formulated with advanced Nanotechnology, it provides a superior bond to treated and non treated surfaces. Rust Blocker Undercoat's high temp formula makes it ideal for engine blocks, manifolds, headers, mufflers and tail pipes because it can withstand temperatures up to 400ºF with 3 or more coats. It provides added UV and rust protection to painted surfaces and dries to a high gloss finish. Clear color eliminates the need to mask off areas and it cleans up easily with solvent cleaner. Can be top coated with most paints.