Zinc Coat Barnacle Barrier 1792 provides protection for bare metals including steel, stainless steel, cast iron, copper, bronze, galvanized steel, and lead. It forms an excellent bond to underwater metals and running gear, and inhibits corrosion on these surfaces. Zinc Coat Barnacle Barrier's smooth, hard surface will self-clean in service, and can be used above or below the waterline. The dried film of Zinc Coat contains 93% pure zinc.