Epoxy hull coatings?

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Nick2

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I have just had all the antifoul blasted off as she seemed to have years of old stuff which really needed to go. It has been suggested that I use the opportunity of a spotless hull to have an epoxy coating.

The boat is nearly 14 years old and there is no sign of blistering etc so is this really a worthwile and necessary idea?

Thanks

Nick

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I've just "primed" some naked GRP on my keel with something called SeaJet Underwater Primer. After applying anti-foul to all the underwater sections the bits that were sanded and the primer applied are much fairer than the rest!
You may find it acceptable just to rub down and prime!

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Yes. Yes @ Yes.....If youv'e gone to the trouble of getting back to the Gel coat for not a lot of effort or dosh, you will have peace of mind IMHO. VC Tar epoxy goes on very easily and provides a good barrier coat against the dreaded blister...Regards Tony W.

<hr width=100% size=1>Tony W.
 
Osmosis is caused by moisture getting through the gelcoat and attacking the polyester resin in the laminate. Epoxy is truely waterproof unlike gelcoat. If the laminate is dry then an epoxy coat will keep it dry and stop osmosis. If it's already wet, then an epoxy coat will just seal in the moisture. It may slow down the process by stopping any more moisture getting in but will not stop it.

Hence there's little to be lost by covering in epoxy if you're back to gellcoat other than the cost & effort. Unless it's a new hull don't expect it to stop osmosis for ever though.

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I agree with Wooslehunter here, but would suggest if you've the time available give the hull every opportunity to dry out before you seal in any contained moisture. Remember, once sealed in, you'll not get out out again unless you remove the applied layor. So it could be percieved as a mixed blessing saving up troubles for yourself futher down the line.

IMHO, regards, Jeff.

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Epoxy is NOT totally waterproof but is far less porous than old gelcoat. Epoxy is stronger than polyester gelcoat and is thus more capable of resisting blister formation should there be osmotic pressure as a result of moisture in the substrate.
As you say your hull has been "blasted", I assume with grit, your gelcoat surface is now likely to be "micro-pitted" and on this basis the apllication of Epoxy would be a good idea.

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Epoxy might be a good idea, but only if you are sure that the hull really is dry. Even if there are no signs of blisters, the laminate may/will have absorbed some water and you will only be sealing it in with epoxy. Check with a moisture meter, take advice from someone who knows and if necessary just prime the hull with anti fouling primer and don't worry about it...

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I would not disagree with any of the above, I would add that if you do the epoxy coating yourself get a surveyor to take moisture readings before you start. Make sure you get a proper report with the locations where moisture was read and the actual readings. If and when you sell it will help enourmously to prove the hull was properly dry. If epoxy coating is not done by a professional some buyers can be put off.


<hr width=100% size=1>Hugh
 
I'm at the same stage. I bought the boat privately 7 years ago and the previous owner said he'd epoxied the hull as a preventative measure. This winter, I stripped all the antifouling off and, in the process, gouged the epoxy in a few places. As a result of this I discovered that he'd only put 2 coats on! Anyway, like you, I was wondering whether I should re-epoxy so I asked the local yard if they'd take some moisure readings. To my great relief, they told me the hull was fine - nice and dry with no sign of osmosis. I'm definitely going to apply several more coats of epoxy now!

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