Electro deposition of copper from acid baths is extremely used for electroforming, electrorefining, manufacture of copper powder and electroplating. Refiner and electroformers; in particular, employ acid solutions because costs of chemicals and power are low and because the baths are simply and easy to control. Electroformed copper articles are produced in several important fields of industry, including electrotypes, phonograph records, band instruments, heat exchangers and reflectors. More than 2700 metric tons of copper anodes are consumed annually in making electrotypes valued at about $ 100,000,000.
Modern method of electrotype molding differ greatly from the procedures of the early forties. Developments have been announced concerning the electroforming of complex shapes with reentrant angles, which can not be made by other methods, for radar, aircraft and other industries. Many kilometers of steel wire are given a copper cyanide "strike" and plated with copper in acid solutions to produce a high strength electrical cable. Thick deposits of copper (200 µm) are apply to steel rolls and then engrave for use in printing and marking paper and textile.
Stainless steel cooking vessel are copper plated in acid bath to improve the diffusion characteristic of outer surface and avoid local hot spots. Copper plating for stopping of carburizing of selected areas is accomplished by striking in cyanide bath followed by plating in cyanide solutions. Acid copper plating sometimes used for building up worn or over machines parts, especially when copper surfaces are desired for protection against fretting corrosion.
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