Electrical cables
Boilers, pipes, valves
Boat helix

There are several cuprous (Cu+) and cupric (Cu++) compounds with many applications. The cuprous chloride is used extensively as a catalyst, desulfurizing agent and decolorizing agent in oil industry. Cupric chloride is used as a mordant in the dyeing and printing of textiles, as an oxidizing agent for aniline dyestuffs and in laundry marking inks. It's also used as a fungicide. The cuprous oxide is used in antifouling paints for steels and wood exposed to seawater and as a fungicide. Cupric nitrate is used in light-sensitive reproductive papers and the cupric fluoride has found use as an opacifier in enamels, glasses and ceramics. Copper sulfate is used as a fungicide, insecticide and soil additive to prevent copper deficiencies in crops and animals and to improve crop yields.