Subject: More questions than a 5 year old.
Date: Sun, 14 Dec 1997
I am one of two wood specialists working for a small boatyard in Norfolk
Va. Currently we are restoring or rehabing 5 wooden boats, ranging from
a 1936 8-meter sailboat (found in a New York City junkyard!!!) to a 1966
45' Owens Aruba. As you can imagine, we run through epoxy. On one of
our projects, a 1962 33' Century that has been refastened and partially
replanked, is now getting new decks. The owner just wants us to use
plywood and epoxy for these decks, as they are going to be painted. I
read your site with great interest, but it raised some questions for me
concerning this project.
Normally, using west system, we would thin the epoxy with acetone to get
better penetration into the plywood, then we would layer on epoxy and
cloth to give the top surface both durability and flexibility. Looking
at your product, I wondered how far it would penetrate 1/2 inch ply, and
if the glues prevented the penetration. Also, is it still necessary to
cloth the plywood? Cloth is used mainly because west system alone is
too brittle and will crack and loose its seal. How would you proceed in
Well, when you get into thinning standard epoxy with acetone, the
penetration is going to depend on how thin the final mixture is. So, we
cannot say that the Clear Penetrating Epoxy Sealer (CPES) is going to
penetrate any further than the thinned West. We believe it does, but
cannot at this point prove it. In a few weeks we're putting up on our web
site a whole new section where we tested CPES vs. a standard unthinned
epoxy and 2 other nationally advertised products that claim to restore
rotted wood. The CPES penetrated up to 20 inches in soft balsa beams;
the nearest competitive products penetrated 3.5 inches. This was partly
due to the composition of the product, but also due in large part that
the CPES set-time was much longer than the competition -- it just had
more time to get where it needed to go.
The other issue here is the nature of the epoxy that you are putting in
and on the wood. As we clear state on our web site, our basic epoxy
resin is derived principally from wood pulp, and therefore has a
different amine structure that makes it tougher and more flexible. This
may not matter if you are constructing a boat, but we believe it is a
very desireable feature when working with wood repair/restoration.
As far as the actual mechanics of restoration, I would do nothing any
differently with our products than you would with West. Our epoxy is not
so brittle as West and the other petro-derived epoxies, but the cloth is
still a needed structural/dispersion component, especially on decks
which can take a lot of abuse -- as you know! With our products, you're
just going to get better penetration (especially into splits, cracks and
end-grain) and a more durable and flexible finish. If the owner insists
that you use no cloth, then yes, our products would definitely be
better. In that case, I would simply soak the plywood with a couple of
coats of the CPES and then go back over it with a high-quality epoxy
paint. But I would warn him that the cloth and resin will give him a
much sturdier structure.
Nextly, how strong are the corners on the pieces that have been
epoxied? We would normally put a 1/2 inch round on a corner that was
getting cloth, for both adhesion and strength purposes. I am curious as
to the durability of epoxied wood on its edges (using your product).
Again, our will be more durable, but I wouldn't give up the 1/2 inch
round. Within reason, you can't do too much to insure longevity of the
Also, what are the drying times on your warm weather and cold weather formulas?
Are they dependent on humidity levels? Naturally, I am only looking for
a loose range of time.
Drying times are longer than other epoxies, because it allows greater
penetration. The CPES at 70 degrees has a pot life of 2 hours and a full
cure time of 2 days; at 50 degrees this goes to 4 hours and 4 days. We
have a Cold Weather formula with a pot life of 2 hours at 50 degrees and
a full cure time of 2.5 days; at 32 degrees this goes to 4 hours and 4
We often apply wood, cloth or epoxy resin on top of the CPES before full
cure time. The molecular bonding between the epoxies goes on anyway. And
yes, West or other petro-based epoxies bond just fine with the CPES.
No, humidity plays no major factor in the cure or final finish of any of
our epoxy products.
Norfolk Boat Works
Congratulations to you guys for your good work on the old wooden boats!
As far as our CPES is concerned, it seems to me that when you consider
that you are paying about $94.00 (Warm Weather Formula) for 2
gallons of mixed product, this has to come close to the West prices, and
it's a whole lot easier. Mix 50:50 and spread it on, that's all. Re-cap
the cans and they'll keep for a couple of years, no problem. And you're
using a better product that will give you better penetration, or so we
Come back at me if I haven't answered all your questions.
Note: Current pricing on all our products can be found on the Product Information page.