Fusion is a terrific all-purpose self-etching-primer ideal for promoting adhesion between multiple surface coatings (including applications of topcoats or primers over cured KBS RustSeal) in addition to priming bare metals such as steel, brass, aluminum, and most hard plastics. Allow you to topcoat over a smooth rock hard RustSeal surface that's been in place for months or years. Just lightly sand the surface using 280-320 grit sandpaper before applying a thin covering coat of Fusion then topcoat as desired. Can be sprayed or brushed on almost any painted surface and is ready for a topcoat in 20-30 minutes.