High-Build Self-Etching Primers fill-in imperfections as they prepare bare metal for non-epoxy topcoats. Etches and primes bare metal in 1 step Fills-in imperfections, sands easily Strengthens adhesion, durability, and color hold-out Use with non-epoxy primers and topcoats Eastwood\'s High-Build Self-Etching Primers have a true acid-etching formula that sticks to virtually any clean, bare, rust-free metal. These lacquer-based, metal-etching primers improve the adhesion and durability of most non-epoxy topcoats, and their high-build capabilities allow you to fill-in low spots and level-out surfaces prior to top-coating. When you use the quart or gallon can, you\'ll need a 1.8-2.0mm nozzle to spray these primers.