The Rot Doctor


Subject: mahogany plywood chris craft top deck
Date: Mon, 04 Jan 1999

I have a 1955 cc cavalier (plywood boat) with a mahogany top deck. I am going to replace the top deck with new plywood (I have been advised not to ever consider using solid mahogany for vintage sake; your thoughts) and was wondering if you have any ideas, refs, products, procedures for sealing the plywood from water to prevent the veneer from cracking/lifting.

Scott G.


Well, your advice is probably good about the solid mahogany. It's certainly doable, but with much more work and an infinite attention to detail. And then, of course, there's the problem of getting good mahogany....

Plywood, with or without a top veneer, can work fine, as long as you take the time to get good ply from a reputable source. And these are generally not the home stores. I would locate the nearest large marine wood supplier in your area, or check Wooden Boat Magazine and look at the ones who advertise, and tell them what you plan to do and ask what veneered ply they would recommend. What they supply WILL cost more because it's better material, but considering all the work you will be doing the additional cost for top materials is a small one.

I would not put any ply down in/on a boat that had not been treated with our Clear Penetrating Epoxy Sealer (CPES), especially the cut edges. On the edges I would apply all the CPES the edges will accept, just brushing it on over and over until the wood will absorb no more. On the broad surfaces I would apply 2 coats, allowing a day or two cure-time between coats. What this will do is partially seal the wood that is exposed to moisture and create a wood surface that is not attractive to rot fungi and bacteria. The edges are of most importance because it is here that the water most often seeps in and the rot gets started. The CPES is a perfect base coat for any paint or varnish.

I would also apply a coat or two of CPES to all supporting wood surfaces, and I'd squirt it into all pre-drilled screw-holes before fastenings are installed.

Come back if you have additional questions.