Barbed Wire
Wire to be made into barbed wire is usually galvanized (coated with zinc) to protect it from corrosion. The wire must be perfectly clean and dry to be properly galvanized. First it is cleaned in a bath of hot, dilute hydrochloric acid, then rinsed with hot water. It then passes through a solution of hot zinc chloride or ammonium chloride to prevent rust from forming as it is dried. After drying, the wire passes through a bath of molten zinc. Excess zinc is wiped off and the coated wire is allowed to cool. (Some-times the wire is coated with aluminum instead in a similar way.) Wire can also be coated with zinc by a process known as electrogalvanizing. The wire is given a negative electric charge and passed through a solution of zinc sulfate or some other zinc salt. The positive zinc ions are attracted to the negative wire and form a coating.