Sideshow Bob

New Member
I'm about to mount a four-stroke on an old boat that's got a weakened glass-over-plywood transom. (The new outboard is almost 85 lbs heavier that the previous 2stroke.) Who's got ideas for a fix that doesn't involve ripping the transom apart? (If this was my forever boat, and I had way more time,this is what I'd do, but my glassing skills just aren't up for it, and I want to get floating asap.)
Anyone tried a reinforcement sandwich with aluminum or stainless plate? With Starboard?
 
I'm about to mount a four-stroke on an old boat that's got a weakened glass-over-plywood transom. (The new outboard is almost 85 lbs heavier that the previous 2stroke.) Who's got ideas for a fix that doesn't involve ripping the transom apart? (If this was my forever boat, and I had way more time,this is what I'd do, but my glassing skills just aren't up for it, and I want to get floating asap.)
Anyone tried a reinforcement sandwich with aluminum or stainless plate? With Starboard?

Sounds like you should re-look at the boat your repowering... I would not chance a motor swap on a soft transom..
 
Many years ago I had a fiberglass boat with a rotten transom. I did a temporary repair using an aluminum plate on the outside and a smaller plate inside, as you suggested. Bolting the outboard on, the bolts penetrate both plates effectively clamping the outboard to the transom. However, the fiberglass skins are thin and without the plywood's strength, are subject to a lot of flexing which eventually weakens the area further.

After running that way for a couple of years I pulled the outboard and gave the hull away. So it can be done but it is not recommended and is certainly not a long-term fix. I would certainly not mount a heavier or more powerful outboard to any structurally deficient transom.
 
Once found a Grady at the Govt. Auction yard that had a full transom size Al plate about 1.5 inch thick , bolted on to the back of the transom, presumably because the transom was rotten. That could not have been cheap to do and the boat still screamed run like hell. Who would spend any real money on that boat? Who would insure it? Who would let you put it in their Marina without a survey? Who would want to get caught out in heavy seas in it?

If it needs a new transom and has wood stringers, there is a good chance they and the deck will also need replacing. The longer the Covid things lasts, the more good turn-key boats will come onto the market and the lower their price will be. Unless what you have available is mostly sweat equity, they could be a better option.
 
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Several of the boats I’ve owned over the years have had some degree of mechanical or structural deficiencies that I knew about.
Every time I got far from home or in a dicky situation I was worried about something going awry. Especially when I had my kids aboard.
Takes a lot of the pleasure out of what is supposed to be a fun time.
Things can go badly really fast out there. Having a boat you’re not sure of will add to the stress whenever something unexpected happens. Just my opinion after doing it wrong (and mostly getting away with it) for years. Mostly isn’t always good enough.
Last year, in a stiff westerly, a log popped up from the wave trough, fifty feet in front of me.
I chopped the throttle & the tilt was on the way up before we hit. Still a mighty great bang when the leg hit the log. Who knows how that would have turned out if I hadn’t been sure that the transom was solid before buying the boat?
 
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I want lots of pictures if you try this.
Make sure all fasteners are out of the transom.
Chain saw out all the punky wood.
Careful not to hit the fiberglass on either side.
Fill with thickened epoxy.
 
Didn't know if "soft transom" and "quick fix" can be used in the same sentence... :) lol - lol

As mentioned if you want safe, its worth while to redo the transom and as mentioned stringers and floor would be questioned as well, i'm sure you can do it in the best part of a week...
 
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Several of the boats I’ve owned over the years have had some degree of mechanical or structural deficiencies that I knew about.
Every time I got far from home or in a dicky situation I was worried about something going awry. Especially when I had my kids aboard.
Takes a lot of the pleasure out of what is supposed to be a fun time.
Things can go badly really fast out there. Having a boat you’re not sure of will add to the stress whenever something unexpected happens. Just my opinion after doing it wrong (and mostly getting away with it) for years. Mostly isn’t always good enough.
Last year, in a stiff westerly, a log popped up from the wave trough, fifty feet in front of me.
I chopped the throttle & the tilt was on the way up before we hit. Still a mighty great bang when the leg hit the log. Who knows how that would have turned out if I hadn’t been sure that the transom was solid before buying the boat?

Prfisher, I can certainly relate. Haywire boats and dodgy, hard-to-start outboards have been a way of life for me for as long as I can remember. That worry does sap away some of the fun, for sure. Safety first, especially with the family aboard! Thanks for the advice from all. A turnkey rig ain't in the cards price-wise... but perhaps it is time to kick the bumpers on something a bit more solid.
 
Prfisher, I can certainly relate. Haywire boats and dodgy, hard-to-start outboards have been a way of life for me for as long as I can remember. That worry does sap away some of the fun, for sure. Safety first, especially with the family aboard! Thanks for the advice from all. A turnkey rig ain't in the cards price-wise... but perhaps it is time to kick the bumpers on something a bit more solid.
I think that is a wise choice. You would not want to drive over a bridge every day that you know has rotten beams, or do you? There are things not worth gambling with. The chance you get yourself in real trouble with your proposal is much greater than dying from COVID. And look, we shut the whole world down for that!
 
You could plate it with aluminum then on the inside run aluminum supports on an angle tied into stringers and it should be rock solid if you don't want to worry about a big transom job right now. Make sure the outer plate is thick enough not to bend and large to spread out the load over a large area.
 
Soft transom fix with aluminum plates will work for a bit, sketchy but works. Seen a few sink after a while, eventually cracks from flexing did them in, if done right it should hold up for a bit, keep a good eye on it and wear life jackets. Ps i will not be going fishing with you lol
 
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