DuPont Teflon Multi-Use This stuff sprays on wet like WD-40, but dries to leave a teflon film. It was recommended to me by my old hardware/lock supplier/locksmith and my automatic garage door opener contractor.
Works great on everything, and does not seem to be harmed by varying temperatures. Of course Northern Ontario has not yet been tested personally.
_________________________
I do the things that I must, and really regret, are unfortunately necessary.
RIP OBG