Here is a quick fact... The name "WD-40" stands for Water Displacement - 40th attempt". It took the scientist 40 tires before he came up with a mixture that would displace water. I think I read that at http://www.wd40.com/ .
In 1953, a fledgling company called Rocket Chemical Company and its staff of three set out to create a line of rust-prevention solvents and degreasers for use in the aerospace industry, in a small lab in San Diego, California.
It took them 40 attempts to get the water displacing formula worked out. But they must have been really good, because the original secret formula for WD-40—which stands for Water Displacement perfected on the 40th try—is still in use today.
What surfaces or materials are OK to use WD-40 on?
WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic. WD-40 can be applied to painted metal surfaces without harming the paint. Polycarbonate and clear polystyrene plastic are among the few surfaces on which to avoid using a petroleum-based product like WD-40.