Originally Posted by phoebeisis
Just curious,but why would the WD40 cause rust?I thought it was just a thin oil that displaces water and coats the bare metal?Thanks,Charlie
It didn't cause the rust. The rust was already there. The rust became suspended in the WD40 and was carried in the WD40 when it drained. Think of it like rinsing away dirt with some water.
WD40 is a poor choice for lubrication or rust protection, but it does not induce rust.