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
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!