Subject: Recurring Rot in '69 Wood Lightning
Date: Friday, 10 September 1999
I recently found considerable rot in the floor plank (below water line) in an area that I treated 5 yrs ago with git-rot. I removed all loose rot with a knife and now have a hole 2.5 feet long and 1 inch wide, pretty much where two planks join. I plan to cut the hole uniformly and patch with a similar wood (tight fit) and screw the patch into the ribs. One rib has about 1/2-inch of rot, all others are in great shape. Should I coat the edges of the hole and the patch with penetrating epoxy? I am concerned about differences in shrink-swell between surrounding untreated wood and the epoxy treated wood. Will this create future avenues for moisture retention?
Yeah, that's the problem with GitRot—it doesn't penetrate.
Treat everything with Penetrating Epoxy (CPES)-- the hole, the ribs, and all new wood going in. Pay particular attention to edges and end-grain areas...this is where the rot usually gets started. For the rib that has the rotted area, treat the area first with the CPES, give it a couple of days to dry, and then go back and apply a coating of our Layup & Laminating Resin to the same area. This will follow the CPES into the wood and give it the substance you need.
Don't forget butt-blocks, i.e., backer pieces of wood on the inside of the hull where the ends of the new wood meet the end of the old wood. And yes, treat everything with the CPES. It doesn't take much and it will pay off big time down the road.
CPES is a very thin coating and there will be very little expansion/contraction differences between the new CPES-treated wood and the old wood. Moisture retention should not be an issue if that worries you, especially if the edges and ends have been CPES-treated.
Come on back if you have additional questions.