Subject: Transom rot
Date: Tues, 24 Mar 1998

Dear Sir,

I have an old Glastron fiberglass runabout that I use only for fishing. The transom is rotten and needs repaired. I need help determining how much and what kinds of your products to order. The transom is 48" wide and 14" deep at the sides and tapers down to 20" deep in the middle.

I cut the top of the transom out to expose the wood. The transom had been replaced by a previous owner about 6 years ago, it only had a thin mat of fiberglass over it.I have already dug out as much of the really rotten wood where the motor mounts in the middle of the transom. This area is 1.5" thick, 15" wide and 5" deep. I could easily put a 2 X 6 in the area where the motor mounts to fill the void. Would this work if I used Epoxy filler around it, and maybe used a few dowels in the 2 x 6 to help hold it?

I drilled several small holes all over the transom to see just how wet and bad it is, some very rotten wood was found, in several places when I broke through the fiberglass it was like nothing was there but powder.

I think I would have to start with Epoxy sealer first, would I drill holes and inject this? Then inject Layup/Laminating resin, followed by Epoxy filler to fill the big void? I have no idea how much of your products to order, maybe you can give some idea. I think I would also need an injection kit, but what can you use to clean this up after use?

Any help would be appreciated.

Gary R.


If I'm reading you correctly, you have the whole top of the transom off, right?

Assuming that's correct, I'd suggest hooking out as much of the wood as you can. Even something as basic as a piece of re-bar, sharpened on one end and hooked -- or anything similar -- will help you get out as much wood as possible. Having done that, let the inside get as dry as possible, even to the point of turning a hair dryer on low and just propping it into position and letting it blow down into the cavity. You may have to do this for hours. Our Clear Penetrating Epoxy Sealer (CPES) will displace moisture, but not water.

Okay. Now flood whatever is let inside the transom with the CPES. Just squirt it along the top with the syringe, back and forth. You might want to just drill a small hole at the lowest portion so you can see when it begins dripping out -- no need putting any more in there than necessary. Give it 4-5 days to cure. You can try injecting it into drilled holes lower down if you feel that there is wood there that won't get the CPES percolating down from the top. I'm not sure this is necessary though, because the CPES will penetrate a long way.

Now, I'd then get some replacement wood that loosely fits into the transom, give it 2 coats of the CPES, especially on the end grain, and drop it into place. I don't think dowels are required, since everything is going to be laminated in place with epoxy resin. Seal up the little CPES drain hole in the bottom. Follow this with our Layup & Laminating Resin, a slow-cure resin which retains some flexibility after curing. Fill all the vacant space with the resin. Give it a couple of days to cure. Finish off with Fill-It Epoxy Putty to a smooth top. This you can sand after curing and should do nicely for the final. It cures off-white and can be painted or gel-coated -- whatever you want. No need really to re-glass the top.

What you've done is fill the transom with stuff that'll never rot. The wood will be rot-proofed because it's CPES coated and enclosed in epoxy resin and the whole thing is sealed off with a very high-quality epoxy filler.

How much material? Always a guess in these situations, because of the variables. I'd suggest at least a 2-quart unit of the CPES, or maybe two of them if there is a lot of wood left inside. The L&L Resin I would recommend three of the 2-quart units -- you do have that space to fill. Finally, probably two of the 2-pint units of Fill-It filler to finish off the top. The Injection Kit should be a big help. You can clean up with our epoxy solvent, and quart should be enough. That should do you.

If I've missed anything get back to me. Always happy to answer questions. All products are in stock and ship within 24 hours.