The Rot Doctor


Date: Mon, 23 Apr 2001

I have a 25 ft sail boat. The hull is made of wood wrapped in fiberglass on the outside. There is a very small leak coming from the junction of the keel and the hull and the wood is wet on the inside.

What products should I use? Can I apply the CPES product while the boat is in the water or do I need to take it out?

Please let me know.


Sammy A.


The wood needs to be dry for any products to seal well. I think you're going to have to haul her and allow the wood to dry. You can then get at the source of the leak from the outside. I would suggest cleaning out the seam, treating it with a coat of CPES (Clear Penetrating Epoxy Sealer), and then following that with a polyurethane sealant, such as 3M™ 4200. The CPES will partially seal, and the 3M™ 4200 will finally seal, and allow the wood to shrink and expand without stressing the keel/planking.

Come on back if you have additional questions.