I recently decanted a part gallon of WD40 into another part gallon. Several globs of a semi solid waxy substance were the last to transfer. The very soft substance was milky in appearance and very slippery. I suspect it is a wax of some sort and it did not feel like paraffin. It has been said WD40 is primarily kerosene, which I don't necessarily accept, and that it evaporates, so doesn't provide any long term protection - other than displacing water. If it does contain some type of wax, it would likely leave a thin film on surfaces, and could provide more protection than often believed. In retrospect, it would probably be a good idea to shake it up occasionally.
Does anyone know what is in WD40?
Does anyone know what is in WD40?