The Rot Doctor


Subject: sealing decks on a 40 ft. monk
Date: Sun, 04 Jun 2000

Hi. I've been visiting your site for a while now. I've just purchased a 40 ft. monk circa 1945. the front deck needs redoing as it leaks. I was told it was canvassed but when I pulled the 'canvas' up it is actually a rubber like blue compound that has been painted. Where water has got beneath it, it comes up just fine but sticks like crazy to the wood everywhere else.

Yup. It's supposed to stick like crazy. That's always the problem with covering decks with material, including fiberglass: The water gets under the covering and things come unglued. And sometimes there is rot, because the covering can act as a mini-greenhouse and produce just moisture/temperature conditions the rot fungi love.

The decks are red cedar and the strips are about 3" wide. What I want to do is coat the wood in CPES, Epoxy them with system 3 (I have a few gallons around) with glass cloth and paint. My Question is... Do I need to cover the decks with plywood first, or can I epoxy right on the existing wood There is no rot or problem areas with the wood except where some of the original caulking has come loose and water has seeped in and loosened the rubber from the deck ( no rot though). There is a local shipwright who insists I re-canvass. Is it better to canvass this type of deck? Will epoxying lower the value of the boat by compromising the integrity of the original? Also what is the easiest way to ship your product up here to Canada? thanks.......Dave.

Epoxying over the existing decks presents a problem in that 1) getting adhesion to the caulked seams will be difficult, and 2) it is almost impossible to get all the moisture out of an old deck, which risks the adhesion of the epoxy. This is why the local shipwright is insisting on the re-canvassing. Traditional canvassing uses the old petroleum based products (bedding, paint) over a material (canvas) that can breathe, thereby giving the moisture a way out.

You can treat the old decks with CPES (Clear Penetrating Epoxy Sealer) to protect them, put down ply that has also been CPES-treated for rot protection, and then glass over the whole thing using cloth and the System-Three resin. If you are careful that the edges are will sealed and good drainage supplied, then this would work.

Will epoxying lower the value of the boat? If she's a sparkling "collector" type boat, yes. If she's your normal "lets-go-out-and-have-fun" boat, then probably not.

What would I do? I'd probably bare the existing decks, CPES them once for protection, and put down canvas. One coat of CPES will still allow the wood to breathe. You should get about 10 years out of the canvas, assuming you keep it nicely painted.

We cannot ship CPES across international borders except by Federal Express Next Day Air -- and it's horribly expensive. Most Canadians have us ship to a point on the US side of the border (relative, friend, Mail Box outlet) and then drive across and pick it up. We supply international paperwork for these orders which contains the NAFTA statement, so there are no Canadian import duties.

Come on back if you have additional questions, or if we can be of further help.