White Knight Rust Guard Cold Gal Silver Spray is an aerosol-driven heavy duty, anti-corrosive coating with a beautiful silver metallic finish. Cold Gal Silver is designed to create a long lasting zinc-rich layer to protect metals in severely corrosive environments while simultaneously providing rust protection for ferrous metals. Cold Gal Silver is suitable for use on steel, wrought iron and other ferrous metals and is ideal for welds and repairing damaged galvanised iron.