I have made a sign with carving and gold leafing. It's going to be outdoors in a tropical environment. I need to know what type of varnish to use, and also what type of maintenance it will need in the future. The sign is made out of 8/4 cypress.
From contributor R:
Seal with Smith's CPES. Scuff and use Epifanes gloss marine varnish. It contains some tung oil and is part phenolic resin. Of the materials ready available, these two will perform the job best. Don't forget the CPES it will nearly double the lifetime of the varnish (ideally 3 coats, thinned 10-20%). As you've no doubt guessed, I've dealt with a lot of boats.