The Rot Doctor


Subject: Bottom/hull coating (with CPES)
Date: Sun, 29 Jul 2001

Planning on doing the bottom & hull of a 1929 ACF Cruiser. I hear that if you do the exterior of a plank below the water line, you have to do the interior also. Is this correct? I want to keep this old girl afloat for a long time coming. Let me know.



Well, what you say is more or less true if you are using a standard, thick epoxy resin, but is not true if you are using our CPES (Clear Penetrating Epoxy Sealer). This is because one or two coats of the CPES do not totally seal the wood, and it is still able to "breathe", although more slowly than an untreated plank.

I would suggest in your case that after the hull has been taken down to bare wood, one good coat of CPES be applied above and below the waterline. You can then finish the hull using the CPES as a prime coating.

I would inspect the interior of the hull. If you see soft or punky wood, then apply CPES in those areas. Where the wood seems solid and fine, then I would leave it alone. This way the planks will have the ability to breathe, while at the same time getting the protection of the thin epoxy saturation.

Come back if you have additional questions.