Silicone shoe spray, no. I spent some time at the local electronics store checking out conformal coatings today. They are expensive and there are different compounds for different boards. For serious protection on the cheap the clear silicon calk/naphtha solution wins. You want to get your pelt installed in an evening? Use Aqua Seal with hardener. It dries in two hours.
I coated my cpu with a wood sealer polyeurathane. works great, But takes a day or two to get all the coatings on. could dump water on it and it would keep running. Also a good idea is to put dielectric grease in you cpu slot or socket to prevent any moisture from getting in there as well.
Thanks guys. Isn't it great to have help like this? I'll check on all three things. (Guess I'll forget the shoe spray, but it was a thought.) Never thought about the thermal elect. stuff. Now if I can locate the stuff I'll be condensation proofed.