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| Zinc plating can be deposited on many base materials including steel, stainless steel, copper brass and aluminum. The most common material to be zinc plated is steel. Zinc plating is a galvanic protector. Zinc plating provides a sacrificial protective coating over steel that will corrode faster than the base material thereby protecting the base material from corrosion until all of the zinc is consumed. Galvanic protectors such as zinc are a good choice to use when the coating may become damaged or scratched. Corrosion resistance is imparted to the damaged area by the adjacent coating. Zinc plating is commonly coated with a chromate to increase its corrosion resistance and impart some color. Common chromates include, blue bright, yellow, and black. As a general rule the darker the chromate the longer it will take to form white corrosion of the zinc. Zinc plate without a chromate is conductive. A heavy black chromate is nonconductive. When grounding is required it may be necessary to abrade the chromate in an area to make good electrical contact. Zinc plated parts will undergo two stages of corrosion. The first type of corrosion to form will be white corrosion of the zinc plate itself. The second form of corrosion will be red rust indicating that the zinc plate is no longer able to protect the area from corrosion. Red rust is an indication that the base material is being attached. |