The Rot Doctor


Subject: old wooden boat repair
Date: Sun, 01 Aug 1999

Dear Doc,
I have an old 14' plywood boat made in 1947 by my father. It's been in a barn for years and I want to use it on the water again. I filled it with water to check for leaks and it does leak. It leaks where the bottom piece of plywood meets the cleat along the sides and the transom. There's a couple coats of old paint on it. The leak is coming from the small gap between the bottom and the cleat on the outside of the boat. Could I fill this gap with your All Wood Glue and stop the leak and still allow the wood to expand and contract?
Thank you for your help.


I'd suggest you do this instead:

Take the paint off the area where the bottom meets the hull sides (actually, it would do the boat a lot of good to take all the paint off the exterior and treat the whole hull), scrape the seam clean of paint residue and debris, wash it clean with acetone or xylene, and then thoroughly soak it with CPES (Clear Penetrating Epoxy Sealer). Use a brush and apply CPES to the seam generously. Allow a couple of days for the carrier solvents to evaporate away, and then fill the seam with the 3-M product 5200. You can get his in cartridges at any marine store. 5200 is a very strong, flexible adhesive that will bond very well to the CPES-treated wood. The CPES itself will seal micro-cracks, but more importantly it will preserve the wood and help prevent rot problems in the future. As noted above, it wouldn't hurt at all to coat the entire hull exterior with CPES, and then re-paint. CPES itself is a perfect base-coat for paint.

If you have any questions about application or technique, come on back and we'll try and answer them.