Ark. Traveler rebuild

[Ray Clark]

I've been following this thread with interest, mostly from a process view.

The other evening I came across a YouTube vid in which a guy was replacing his rotted transom. He appeared to be facing a number of the same issues as you have been encountering with holes and screws and so on. I'm linking that video HERE. I think the vid is worth the time, even if you don't use the primary solution he used. It may spark some ideas as you solve the challenges you face with your boat.

The vid shows the guy using a pourable epoxy to replace the rotted ply in the transom. It was more expensive than ply, but less expensive than COOSA board. It provided a waterproof structure and did not require him to remove all the through-transom obstacles like drainplugs and such. He discusses how he dealt with those obstacles. The pourable also easily deals with irregular surfaces.

I understand what you have said several times about cost. But your time and labor are also resources that cost something, even though you might tend to discount its value. Decent quality plywood does cost, and there will be some waste; it's inevitable. There will always be a trade to be considered. How much is your time valued against the cost delta between the less expensive plywood solution (with all of the adhesives, sealant, and such) and an alternative solution?

 

[Ronbedard57]

Hi again.
I'll get a few photos of the completed job on my own CS-14 The plywood does not go all the way down to the bottom and there's an inch or so gap above the hull so as to keep dry when there's some water in the bilge. The new plywood pieces that you'll laminate in place can be slid in and then pulled up to tuck tight under the cap channel.
All of the screw holes you mention might be handy if you use some 1-1/2" coarse thread drywall screws with fender washers and draw the layers tight against the aluminum, and then to each other. Once the first layer has cured, remove the screws, drill out the holes so that the screw threads will only engage with the 2nd layer of plywood when you repeat the process. You'll be drilling through the paths of those clamping screws when you install the through-rivets after everything has cured. You'll have to aim carefully when you drill through for the rivets that fasten the knee. I drilled halfway through from each side and had pretty good luck.
I don't believe there's any good call for using screws in the final product. They're certainly not how things were done originally, and the P.O. probably installed them when he saw the transom starting to go bad.
When you're installing rivets, remember to avoid the area where you'll be placing the pad for the motor mount area. You could use plywood, but a piece of 1'4" aluminum plate isn't too expensive, and is much more durable. Rivet straight through the entire sandwich for strength. I bedded the plate in some of that gutter sealant stuff I mentioned in an earlier post.
I hope that my explanations are clear enough to help you through this, and I assure you that the end result I achieved left nothing to be desired.

 

[Fishbrain69]

Ray Clark's epoxy suggestion reminds me of a wooden skiff that I restored back in 1977 that I had bought for $30 since it had been submerged for at least several months in an estuary and was covered in oyster shells. After months of grinding and sanding I poured fiberglass resin into all areas where the wood was disintegrating and spongy. It worked amazingly well, turned everything rock hard including the transom, was easy to apply and kind of fun too. Best of all the boat performed well in all water conditions including on a small craft warning day when I wondered why there were no boats visible anywhere. In retrospect I chalked it up to being young and stupid. Now I'm old and almost as stupid.

But you need to work outside ideally with a stiff breeze or use a large fan. Your brain and liver will thank you for it. The speed that these vapors pass from your lungs into your bloodstream makes even short term exposure unwise. The effects are additive over time. Whenever OSHA warns about adverse health effects on any subject, there's pushback from industry to squelch it. No surprise there. Considering what I just wrote, I'd have to conclude that marine epoxy would be a much safer way to go than fiberglass and just as effective, IMHO. Progressive Epoxy out of New Hampshire sells VOC free epoxies that I mentioned in my previous reply in this thread.

 

[birdsnest4ever]

I've been following this thread with interest, mostly from a process view.

The other evening I came across a YouTube vid in which a guy was replacing his rotted transom. He appeared to be facing a number of the same issues as you have been encountering with holes and screws and so on. I'm linking that video HERE. I think the vid is worth the time, even if you don't use the primary solution he used. It may spark some ideas as you solve the challenges you face with your boat.

The vid shows the guy using a pourable epoxy to replace the rotted ply in the transom. It was more expensive than ply, but less expensive than COOSA board. It provided a waterproof structure and did not require him to remove all the through-transom obstacles like drainplugs and such. He discusses how he dealt with those obstacles. The pourable also easily deals with irregular surfaces.

I understand what you have said several times about cost. But your time and labor are also resources that cost something, even though you might tend to discount its value. Decent quality plywood does cost, and there will be some waste; it's inevitable. There will always be a trade to be considered. How much is your time valued against the cost delta between the less expensive plywood solution (with all of the adhesives, sealant, and such) and an alternative solution?

I have been giving it a great deal of thought, and I am leaning toward the pourable epoxy. I'm thinking that that would seal all those damnable holes but I was going to put rivets in them anyway, I am going to watch that video in a bit. I appreciate all knowledgeable help.

 

[birdsnest4ever]

Hi again.
I'll get a few photos of the completed job on my own CS-14 The plywood does not go all the way down to the bottom and there's an inch or so gap above the hull so as to keep dry when there's some water in the bilge. The new plywood pieces that you'll laminate in place can be slid in and then pulled up to tuck tight under the cap channel.
All of the screw holes you mention might be handy if you use some 1-1/2" coarse thread drywall screws with fender washers and draw the layers tight against the aluminum, and then to each other. Once the first layer has cured, remove the screws, drill out the holes so that the screw threads will only engage with the 2nd layer of plywood when you repeat the process. You'll be drilling through the paths of those clamping screws when you install the through-rivets after everything has cured. You'll have to aim carefully when you drill through for the rivets that fasten the knee. I drilled halfway through from each side and had pretty good luck.
I don't believe there's any good call for using screws in the final product. They're certainly not how things were done originally, and the P.O. probably installed them when he saw the transom starting to go bad.
When you're installing rivets, remember to avoid the area where you'll be placing the pad for the motor mount area. You could use plywood, but a piece of 1'4" aluminum plate isn't too expensive, and is much more durable. Rivet straight through the entire sandwich for strength. I bedded the plate in some of that gutter sealant stuff I mentioned in an earlier post.
I hope that my explanations are clear enough to help you through this, and I assure you that the end result I achieved left nothing to be desired.

A lot of my grief came from the fact that the original transom went all the way to the floor. It appeared that the transom was put in then the stern plate was installed and riveted because it was all the way up under the cap, and I destroyed the cap getting the rotten wood out. There is even 2 3/4 inch holes that were drilled through the transom after the motor was mounted and then bolts ran through both the transom and the motor. No was it was ever going to fall off. I'm going to eliminate those because I don't think that little 8 horse will ever go fast enough to lose the motor.

 

[Ronbedard57]

I guess there’s more than one way to skin a cat.
If I were going to go that route, I’d try to get the boat stood on its end and shimmed “level”. Maybe patch all the places the goop could escape with tape, and do a test fill with a measured volume of water. That’d tell you how much to mix up. I imagine there’s some sort of matrix material to imbed into the pour for added strength. Someone else is likely to weigh in about that.
I’m looking forward to seeing how it goes.

 

[Ray Clark]

Just saw this morning that the guy in referenced vid did a one year follow up. Linked here.

 

[birdsnest4ever]

I guess there’s more than one way to skin a cat.
If I were going to go that route, I’d try to get the boat stood on its end and shimmed “level”. Maybe patch all the places the goop could escape with tape, and do a test fill with a measured volume of water. That’d tell you how much to mix up. I imagine there’s some sort of matrix material to imbed into the pour for added strength. Someone else is likely to weigh in about that.
I’m looking forward to seeing how it goes.

I wish there was a way that I could stand it up. Unfortunately there isn't. I can't even get it off the trailer, well, I could get it off, but I worry that I couldn't get it back on. My mind still thinks I'm 30 but truthfully I just turned 74.