Plywood Transom in Well

Fire99

Fire99

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Well Well Well (excuse the pun!)

Further to my Cockpit floor issues, after further probing, the aftermarket encased plywood transom which seals the boat from the outboard well, has got rather spongy in places.

After a lot of stripping back of fiberglass covering, the transom has been removed. Obviously the fibreglass which coats the whole Well, will need repair but are there any tips or best practice when refitting a replacement plywood transom?

Thanks again..
 
Fire99 said:
Well Well Well (excuse the pun!)

Further to my Cockpit floor issues, after further probing, the aftermarket encased plywood transom which seals the boat from the outboard well, has got rather spongy in places.

After a lot of stripping back of fibrglass covering, the transom has been removed. Obviously the fibreglass which coats the whole Well, will need repair but are there any tips or best practice when refitting a replacement plywood transom?

Thanks again..
Click to expand...

Treat the ply with an epoxy resin.

You can improve the penetration on the end grain by thinning the epoxy wit Methylated Spirits up to 30% by weight or volume.

Best results in teperatures above 20c and humidity below 73%.

Good luck and fair winds. :)
 
Ahh thanks.. I hear there is some special penetrating Epoxy available (CPES). Are they worth the expense for the job?
 
Plywood transom

A said epoxy diluted at first. Then cover the whole thing with fibreglass (epoxy resin). I think if you are going to keep the boat for a long time the fibreglass needs to be quite thick. Not just enough to keep water out of the plywood but enough to make the fibreglass strong in itself. So f/g a cm thick would do the job even if the plywood were rotten giving only a little support. On the other hand the plywood should be good for a few years so you decide.
I might have suggested more fibreglass over the original rotten transom to make effectively a f/g transom on a rotten wood mold. But it sounds like you have already replaced the plywood. good luck olewill
 
William_H said:
A said epoxy diluted at first. Then cover the whole thing with fibreglass (epoxy resin). I think if you are going to keep the boat for a long time the fibreglass needs to be quite thick. Not just enough to keep water out of the plywood but enough to make the fibreglass strong in itself. So f/g a cm thick would do the job even if the plywood were rotten giving only a little support. On the other hand the plywood should be good for a few years so you decide.
I might have suggested more fibreglass over the original rotten transom to make effectively a f/g transom on a rotten wood mold. But it sounds like you have already replaced the plywood. good luck olewill
Click to expand...

Many thanks for that. In hindsight, Leaving the transom in situ and beafing up the fibreglass may have been the easiest option but to be honest, because I kept finding damp wood, I really didn't want to take any chances with a hidden 'surprise' that may cause a leak.
At least now I know exactly how the Well was constructed and any leaks will be my fault. :) (Am I sure that's a good thing??)

On the fibreglass matting front, is there a recommended weight for such jobs?
 
Fibreglass Matting

Chopped strand mat is not suitable for Epoxy (there may be exceptions) the strands are stuck together with a substance which dissolves in polyester resin.(necessary) It does not dissolve in epoxy.
You use epoxy for good adhesion to the wood. Polyester will not stick to wood very well.
So if the f/g is really thick then adhesion to the wood doesn't matter so you can use polyester and Chopped strand mat.
For epoxy you use lots of the heaviest cloth or you can by woven rovings. really thick f/g cloth that is woven so not stuck together like mat. This makes it much better but more expensive.
(of course there may be new cloth products around now in Uk that I am bot aware of) good luck olewill
 
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