And it also evaporates eventually leaving a varnish like residue, which can gum things up.I've "liked" this because people should realise that WD40 is a Water-displacer, and nothing else: it is NOT a lubricant, nor is it a penetrant, and if used as a honing oil it will gum-up the oilstone and defeat the object of a honing-oil; which is to keep the oilstone free of metal particles.