This easy-to-use quart etches and primes bare, rust-free metal in one step, saving you a great deal of time. Adheres to steel, aluminum, stainless steel, and galvanized steel and is compatible with virtually any paint or auto finish. It is also a single-stage formula which requires no catalyst, making it easier to use. NOT FOR USE UNDER CHASSIS BLACK. Quart comes pre-thinned for spraying. Buy 3 or more and SAVE!