The Rot Doctor


Subject: about my boat (replacement deck repairs)
Date: Tue, 13 Apr 1999

I have a teak & african mahogany (allegedly) cutter, 27 feet on deck. The decks were replaced by the previous owner. He replaced a couple deck beams, most were fine, and laid plywood and covered it with fibre glass. I don't know what brand/type goop he used.

He didn't want to pull up all the trim as the edge of the deck - the toe rail and stuff along the top edge of the topsides. I don't blame him, it is original and in good shape.

So he cut the original deck (it was plywood covered with teak planks) about 2 or 3 inches in from the edge of the deck. This left some pretty questionable stuff there. I don't think it takes any load, so not problem there. But it will promote decay in what's around it, no?

The real problem is at the joint of the old/new deck ply. There is a difference in how the new/old ply moves, and the glass sheathing is cracking in a couple places. One is about a two inch ripple, another was a 3 inch tear last fall and is now an 8 inch tear.

So I'm going to pull up or grind the glass in the problem areas, seal the wood and patch the glass. I suspect I will be doing this on an ongoing basis until the whole thing settles. (The new deck is just reaching two years old.)

I've always used West Systems epoxy. I was about to switch to System 3 or (brand x) that I saw at the P.T. Wooden Boat Festival. And now you have to complicate things by giving me another choice! All those other products, at least as far as I'm aware, are much thicker than the "diesel" consistency of your epoxy sealer. So, I don't know what I'm asking here. I guess I'm looking for reassurance that this is a proper application for your product.

best regards,



I understand your problem and I DO know what you're asking.

You've got two goals here: 1) Handle the existing rot problems and make the wood highly resistant to future rot, and 2) get something back down that has a chance of staying there.

Our CPES (Clear Penetrating Epoxy Sealer) is formulated to solve problem #1. It is very thin and penetrates deeply. It stabilizes the wood it coats and will restore solidity to rotted wood. The only condition is that the area must be reasonably dry before the CPES is applied. After you grind/rip everything down and get it cleaned up for a new surface application, I STRONGLY suggest you give the entire area a coat of CPES. This will give you good protection down the line and also serve as a perfect base for your new surface. You might also consider applying CPES to any other areas of the new deck/old deck interface that have any gaps or cracks. Good protection. Only CPES is thin enough to penetrate this deeply. Don't even think about anything else.

Now problem #2. Probably the previous owner used a polyester resin to lay down the glass cloth on the new deck. Polyester resin is very brittle and so any movement due to wood expansion or contraction is going to result in exactly the splitting/tearing situation you are facing. So, this being true you want to replace the glass cloth with epoxy, which is something you have already concluded. But which epoxy, right? I am going to argue that based on our testing (see it on the web site in the "more info" sections under Layup & Laminating Resin) our epoxy resin is more flexible when cured than the ones made by other companies. There have been arguments on line about how important this is and whether it worth the extra cost of our L&L Resin. Obviously we think it is. Does using our L&L Resin guarantee that you will not face the ripping/tearing problems again? No, we cannot say that because too much depends on the degree of expansion/contraction, as well as a lot of other factors. We can only say that we believe you have a better chance of success with our resin than others. And saying this is not to knock the other resins -- they are perfectly good. We just think for this particular application ours might be more suitable.

Beyond all this, your logic sounds correct. You'll just have to keep watching and replacing as required. No matter what resin you end up using, DO use the CPES. Any epoxy resin will bond with it, and it WILL protect your wood.

Come back if you have additional questions. We want to be as helpful as we can.