Rotten Dinghy Transom - Suggestions?

Bugsy

Super Anarchist
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Canada
This is a ~60 year old fibreglass Albacore dinghy.  It is sailed recreationally.   

The transom appears to be fibreglass over plywood.  The plywood is rotten.   The arch over the opening for the tiller is broken and is only held in place by the traveler.   

Everything still works and the boat is functional but I would like to do something about this.  Easy and low-cost are preferred options.  One option would be to just cut the arch off and glass the transom flush with the aft deck.  I could then install a bridle to support the mainsheet block.   A functional traveler is not required.  

Anyone have any useful ideas or suggestions?  

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steele

Super Anarchist
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Land of the locks
I did a similar repair on a rowing dingy. In your case you could cut the deck layer skin off and try to preserve the arch, or as you say just cut the whole thing off flush, either will work for casual use. In my case the transom plywood was rotted amost to the bottom of the hull. Rather than pulling the skin off the outside or inside, I just dug as much as a could out using long screwdrivers and other inappropriate tools and then put a few heat lamps on it. After getting it pretty dry I flooded the space from above with epoxy thickened with microballons, adding bits of new plywood to take up some space in the void to reduce the amount of epoxy needed.  The end result lasted for years, even allowing use of a small outboard on the transom. If you go this route you could sink bolts with a large nut on the end for the bridle mounts while the epoy is wet.

Bridles work fine for lasers, laser 2s and I am sure other dingys, but you may be able to straiten the track you have an bolt it back down.

 
You should check how far the transom has rotted down. It’s always where water is trapped for long periods. In this case deck to transom joint but I’d also check hull to transom joint at the bottom.

If it’s all mush, the transom will have to come out and a new one put in. Uninstall your rudder fittings off the transom. If there is moist or black wood particles coming out with the fasteners, it’s gone.

 

asmo

New member
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BC Canada
I did just like steele described for the little rowing dingy we keep tied to the dock. Cut my hands pretty good scraping ALL the rotten wood out from between the fibreglass inner and outer skin. Made a new plywood transom, and embedded it in thickened epoxy leaving an inch or so of solid epoxy at the top. Four(ish) years and zero maintenance later it’s holding up great. If I had another rotten transom to repair I’d do it exactly the same way.

 

Bugsy

Super Anarchist
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Canada
Thanks, everyone.  Appreciate all the responses. 

For the bridle, I am thinking of setting a pair of stainless eyebolts in the transom, like below, as I rebuild.  Anyone see any problems with that?

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That looks alot like my ancient Whitby Albacore.  Someone had updated my traveler with a harken and used those at the corners because the car had sheaves.  Anyway it looks alot cleaner when people just poke holes with chafe protection and lead the bridle through the holes.  The same holes your going to drill for the eyebolts anyway.  I'll see if I can find a picture of what I'm talking about.

 
Most likely the entire transom core is mush.

I’d remove the outer skin, ‘cept the edges,  and the mush, clean up the inner skin, and rebuild, using foam core  with hard spots of coosa board or strong epoxy putty for the rudder hardware. 

A bridle traveler will work fine. 

 

Zonker

Super Anarchist
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Canada
I'd build a brand new foam core/glass transom. Lay it up on a smooth mold table. Trim. Glass to hull and deck (I assume you can get to the inside trandom/hull joint) 

Then you only have to fair the external taping and waste hours scraping out old rotten plywood. 

 
My Albacore, Whitby 2340, the transom is mostly skin with the plywood part shaped like a "T".  Basically the plywood only supports the traveler over the hole for the tiller out to the corners and in the middle under the tiller hole down to the bottom to support the tiller hardware.  That strip is only like 4 inches wide if memory serves.  Of course someone may have modified mine over its many years.

 

Grrr...

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Detroit
I'd build a brand new foam core/glass transom. Lay it up on a smooth mold table. Trim. Glass to hull and deck (I assume you can get to the inside trandom/hull joint) 

Then you only have to fair the external taping and waste hours scraping out old rotten plywood. 
It may be more work than the boat is worth, but this is what I'd do as well.  Just finished it on a S2 7.9 and that will last the rest of the boat's life since it was done right.  Grab a dremel and start cutting back until you hit dry.  Rip out the old core, replace the new.  Use marine ply and cut a piece that makes you happy for that fancy tiller cut out.  Smack some bog and 2 or 3 layers of glass on the whole thing, sand, then paint the whole stern.  It's a week or two job if you're doing it at home.

 

See Level

Working to overcome my inner peace
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Over there
Cut and peel the transom skin off  2 or 3 inches in from the edge, dig out the rotten ply an replace with new core as needed, glue the skin back on.

Probably don't need the arch.

 
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