Cold Galvanizing Compound is formulated of 90% pure zinc. It chemically fuses to bare steel forming a permanent barrier. Even if scratched, the zinc will deter rust from starting. Acts as a great weld-through coating: ideal for treating the inside surfaces of new replacement body panels which will not be painted, but need superior, long-lasting protection from rust. NOT TO BE USED AS A PRIMER OR PAINTED OVER. Buy 3 or more and SAVE!