Touch-up and repair of hot-dip galvanized steel is key to maintaining a uniform barrier, providing cathodic protection, and ensuring coating longevity and continued corrosion protection. The method to repair hot-dip galvanized coatings in the plant or in the field is contained in ASTM A780. The specification includes three acceptable materials for touch-up and repair of hot-dip galvanized steel: Zinc-based solders, zinc-rich paints, and zinc spray (metallizing). less