The Rot Doctor


Subject: Restoration: Penetrating epoxy question
Date: Tue, 30 Jun 1998


I have been asked to take on the restoration of a 14' rowboat; it is quite a bit removed from my usual wood canvas canoe restorations, so I am fishing about for some information.

The boat is 14' by approximately 38" beam, cedar stripped over oak frames. Originally it would have had no sheathing, but has been glassed. As a result, the keelson and roughly 8 strips on either side have rotted, and will be replaced after removing the glass.

In an ideal world, the boat would be restored and used without re-glassing the hull. However, trhe customer plans to have it live on a trailer, and wants it glassed for added strength and not to have to soak up after storage. While it is a stretch from my usual attitude towards mixing fiberglass and wooden boats, I believe in this case glassing the exterior and sealing the interior with epoxy is justified.

My current plan is to replace all the rotted wood (keelson, planking and some ribs), encapsulate the wood on the interior (removing and sealing the backside of the ribs, but not actually getting to all surfaces of the strip planking or the point on the stem where the planking fairs in. The boat will then be glassed with 10oz glass.

My questions are:

1) does this seem like a reasonable approach?

Yeah, sort of.... Like you, I think glass covering encourages rot. But I do understand your customer's point of view. If I were doing it myself, I'd coat the EXTERIOR with the penetrating epoxy, and then cover with cloth and EPOXY resin. I'd then leave the interior with one thin coat of the penetrating epoxy, OR paint, but not both. You want the wood to breathe, which it will only do from the inside.

The epoxy resin on the outside with the penetrating epoxy as a binder will give you the tightest adhesion, and the adhesion will help keep the water out. And then of course the epoxy resin is much stronger than the polyester.
A little more expensive, though....but so much better!

2) Is Clear Penetrating Epoxy Sealer an appropriate product for coating the interior?

Sure, but one thin coat only. See above.

3) Roughly how much can I expect to use on a boat this size?

Outside I'd guess about a gallon mixed liquid and the same inside, or maybe a little more, given the frames and nooks and crannies.

Thanks much for any advice,
Daniel M.
Five Lakes Wooden Boat Center
"So many boats, so little time..."


Glad to be of help, if I was. I do feel strongly about the epoxy on the exterior.

Come back if you have more questions.