Subject: Boat Project
Date: Sun, 2 Nov 1997

Dr Rot,

If you look at the pictures (below) you'll see what I am doing. Need to fill that hole and mount a 225hp evinrude. I have a bracket that will straddle the hole. But I am not sure that I want to use the bracket.The engine alone will not straddle the hole. I want to get as much strength in the hole as possible. The transom is flat and gelcoated on both sides. I figure on plating both side's with 3/16th" stainless. Sorry ,but there is no rotting wood that I can find. The plywood you see in the pics is solid. I have ordered some of your CPES to soak and coat this plywood. First I am going to use a wood chisel and cut the plywood back about an inch all the way around the hole, that would leave about a 1/2" of glass on the inside and outside as a lip. Then coat it with your CPES. After that I am not sure about the best way to proceed. I was thinking I would just form the hole with plywood on both sides and pour epoxy mixed with chopped glass and fill the entire hole in one shot. Would you do it this way? Please advise what materials you have that I should use.

Thanks Dunk.


Thanks for the pictures.

Yep, I would do it your way. You definitely need to fill that hole, and completely. The SS plate will take a lot of load, but 225 hp is a big engine and will make a big thrust/torque force. Make sure the epoxy is a slow-set formula (such as ours) so that it will have plenty of time to settle in and not give you a hot mix. Micro-balloons are lighter than chopped glass, but a hassle to mix/handle. Also, be sure that the SS plate is large enough to distribute the load over a broad area of the transom.

Soaking the wood with the Clear Penetrating Epoxy Sealer (CPES) is necessary. I'd give it 2 coats, and pay particular attention to the ply end-grain. Let it soak up as much as it will take.

You will need to pay particular attention to getting a watertight seal on the plywood plugs used to contain the filling mixture. Again, use our CPES first and then perhaps a little resin and finally an epoxy sealer -- such as our Fill-It Filler. I would also use a bead of something like 3-M 5200 around the patched hole to keep water out. May sound like overkill, but you don't need the moisture getting in there.

Let me know if you have any more questions. And thanks again for the pix. They make answering your questions much easier.