"White Rust"

Although steel and iron corrode into the familiar reddish-brown "red rust", when other metals corrode the corrosion products are not usually red. When copper or nickel corrode the corrosion products are often blue or green. When aluminum corrodes the corrosion products are white, or preferably transparent.

When zinc corrodes, it forms a somewhat sticky "white rust".

Zinc is a very widely used metal:

• Some items are made of solid zinc because it is inexpensive and readily and rapidly pressure cast into complex shapes (some people call zinc diecastings "pot metal" or "white metal"). The end brackets holding up towel bars in almost every bathroom are examples of zinc diecastings (in this case they are usually nickel plated).

• Zinc is also electroplated onto nearly all steel nuts & bolts and related hardware, as well as deposited onto roofing material, electrical tower structures, etc, via hot dip galvanizing.