It completely removes medium to heavy rust and tarnish, and does not leave behind gray discoloration. Corrosion is removed rapidly and can be used to clean and deoxidize all ferrous metals, copper, aluminum and their alloys. On heavily corroded parts, scale and rust will be removed, but heavy surface roughness and pitting cannot be repaired. The product may remove or bleach some paints. Zinc and galvanized coatings may also be attacked. Test product before full-scale use. Use Zerust Axxaclean^™ 2048 if a less acidic product is needed.