Quote Originally Posted by Utopian View Post
I would say it makes sense that WD40 can dissolve grease, but I do not agree that WD40 is hygroscopic. That makes no sense. First, I don't know of many oily substances that are hygroscopic. Second, the name of WD40 is from the chemist who was trying to derive a water displacing anti-corrosive. The name is an acronym for Water Displacement attempt number 40. If WD40 caused rust, I doubt if it would be as commonly used as it is.
Most of us in my business wont touch the stuff as it seems to create additional problems. While it does loosen problematic nuts and bolts and free up hinges and moving parts those benefits tend to be short lived and in short order these parts begin to stick real bad and I have also noticed a serious tendency towards rust on the stuff I had used it on before I knew better.