Permatex oxide treatment destroys old rust and prevents new rust in a single step. Simply brush or spray and within minutes the rust is replaced by a durable black polymer coating, which can be painted and serves as an excellent protective primer. Specially formulated to be used with body filler and fiberglass, this oxide treatment can be used at temperatures between 50.0 °F and 89.6 °F and on surfaces not exceeding 199.4 °F. It destroys rust in all automotive applications, trucks, trailers, storage tanks, pipes, valves, fences, bulkheads, covers, hatch covers (top layer with suitable marine paint), agricultural equipment, plows, tractors and snow removal equipment. It is not recommended for repairs of car outer sheet metal.