The Rot Doctor


Subject: I'll bet no one's asked this before...
Date: Wed, 15 Aug 2001

For a barn themed bathroom, we are building a set of shower doors made with wood. We are choosing the wood (looking at mahogany and cedar) and what to seal the doors with. Since the wooden doors will be exposed daily to water (filtered), steam and soap, how do you think your products would hold up to avoid rot and warping? What advice, if any, would you give us? This may be a whole new audience for your products, since my architect hopes to have this bathroom featured in a major interior design magazine and every detail, including sealers, would be reported. Thank you.

Well, we do get into these kinds of projects once in a while!

Here's what I'd suggest: After the doors are cut, trimmed, sanded and ready for installation, they should be coated twice with CPES (Clear Penetrating Epoxy Sealer), including all latch/knob/handle openings or cut-outs. Any end-grain areas should be allowed to absorb all the CPES that they will. You should allow a day (or longer) between CPES applications.

After the final coating of CPES has cured (about a day), coat the doors with a polyurethane clear finish, gloss or matte. I would apply at least three coatings of the urethane. The urethane will bond with the CPES-treated surface and the wood will be completely protected.

If screws or bolts are used to fasten the doors in place after the treatment of the wood, the pilot holes for the fasteners should be dabbed with CPES to protect the interior wood.

CPES is clear, and when applied to new wood darkens it slightly and highlights the grain. Looks quite nice, actually. It is commonly used for this purpose on high-gloss marine exteriors, with a polyurethane varnish as the final coating.

Coverage for CPES on new wood is about 200 sq. ft per gallon first coat, and 300 sq. ft per gallon 2nd coat.

Come on back if you have further questions. Sounds as if you're going to have beautiful shower doors! And they will be protected using the above process.