I recently discovered that if I spray a lot of WD-40 on steel as a rust preventer, if it pools, say between saw blades in a stack, it actually causes rust. Is there a reason for this?—Wayne Baker

Peter James replies: WD-40 is a product that people either love or hate. It is a water displacing agent, not a long term protector. If you Google “WD-40 and Rust”, you will find endless reading on this subject. There are better ways to protect your saw blades. Stacking them so that the teeth can contact each other is not good. If you must stack them, make a simple holder with a wooden dowel and flat board and put flat washers between the blades to provide separation. Coat the blades with paste wax to prevent rust.

Rust