Coating of a ferrous metal by passing it through a bath of molten zinc or by electrodeposition of zinc. In the former process, the iron and zinc combine to form an intermetallic compound at the interface, the outer surface being relatively pure zinc, which crystallizes as it cools to form the characteristic spangle. The electrodeposition method gives a uniform surface that may be either dull or bright. Duration of corrosion protection is directly related to the thickness of the zinc coating.See Sacrificial Protection.