Subject: Well done (Pt.2)
Date: Mon, 23 Mar 1998

Doc-------------thanks for your words. I think there is a general misunderstanding amongst shipwrights, like me, that penetrating epoxies don't allow wood to breath. Maybe you can answer this on your website; what are the properties in penetrating epoxy that allow wood to breath whereas other epoxies do not? Look forward to your explanation, and our future communications.-------------------gary


Good suggestion, and we'll try an deal with it. I do think the problems is just that most folks think of epoxy as a fairly thick encapsulating liquid, which of course won't breathe. The penetrating epoxy mixes up at about the consistency of diesel fuel, which is pretty thin, and it has a tendency to encapsulate itself in and on the wood fibers rather than the spaces in between. If you put enough of it on then it WILL encapsulate. It's kind of a hard thing to demonstrate (and I know from experience that shipwrights want proof -- and I don't blame them) We are now considering microscopic analysis with attached camera equipment as a way of taking photographs that might be helpful.

You can test this empirically by using your mouth to push air through an untreated of standard marine lumber, then giving it a coat of the penetrating epoxy and trying the same test again. You can still push the air through. Won't work with a standard epoxy. Plywood is a special problem, and IMHO it should be liberally coated with penetrating epoxy, especially the edges. Anything to keep the moisture out, and the ability to *breathe* is not the issue with ply that it is with standard lumber.

The penetrating epoxy does seal off the wood to some extent and makes the entrance of water and rot fungi more difficult. Furthermore, it creates a surface environment that the fungi and bacteria do not find inviting. We would never claim it is foolproof, but it does discourage deterioration. Furthermore, the penetrating epoxy is a really fine prep for paints and other finishes.

Thanks again for your suggestion. Keeps us motivated!