I think a few people gave this stuff a go some time ago. Seems like the business for Trailers, break hubs and springs, break cables and all sorts of stuff. You spray it on, in it's liquid form. The liquid evaporates to leave a sticky film that is waterproof.
Anyone tried it before
Here is a data sheet on the product http://www.wurth.co.uk/catalogue/pdfs/UK-CD_06_0615.pdf
Any thoughts you have would be appreciated. I have found a supplier and was thinking of treating the exposed and dunked trailer parts to a coating.
Kevin