osmosis prevention

[paulburn]

Dear All,

I have just bought a 10 year old trimaran and am keen to get the bottom epoxied as prevention against osmosis.

She has been out of the water for about a year and I keen to get the job done ASAP before the sailing season. The boatyard say they can do it in a tent within a hangar with temperature and humidity control, using Blakes.

My question is, is it reasonable to epoxy in mid winter under these circumstances, not knowing how conscientious the boatyard will be about humidity etc

many thanks !

 

[Cerddinen]

The best answer to this question can be found by reading "Fibreglass Boats" by Hugo du Plessis. My reading of his work is that he would advise against. If you epoxy when the hull is wet it can have the effect of trapping the moisture. Further, unless the yard are really experts they can do more damage than good.

 

[oldsaltoz]

G'day Paulburn,

It would be nice to have the boat all ready to go when the season starts. But at what cost, have you asked for a price? have you checked how much you can save if this work is done in warmer conditions?

Also, have you got a detailed list of the application methodology they plan to use? The better outfits actually add a thin layer of cloth then fair the hull before adding the 4 coats of resin, and a coat of high build epoxy primer.

Will fairing be included, prior to treatment?

What warranty is offered and what conditions apply?

You don't have to be a rocket scientist to work out the extra cost and time added by doing this work in winter, as opposed to warmer conditions.

For what it's worth I would not even consider applying any epoxy / osmosis treatment during cool or high humidity, primarily because the whole thing relies on the control system running without fault 24/7.

My advice would be to check out what you will get for your money, and I mean a detailed statement of procedures and methods, and get this from more than 2 others.

I hope this helps.

Avagoodweekend......



temperature and humidity control, using Blakes.

My question is, is it reasonable to epoxy in mid winter under these circumstances,

 

[exfinnsailor]

Why not look at CopperCoat .. Epoxy based antifoul .. Could save you some time and efort and will give the same benefit as epoxy coating .. Application methods vary but might be worth a phone call

 

[Csail]

I wouldn't even bother, had mine done and its come back , also cost about 5k.

 

[flyingscampi]

As Jazz suggested, if the hull isn't dry (unlikely this winter) you're sealing moisture inside your hull which can accelerate the onset of blistering (if your hull even contains the water absorbing resins and chemicals that cause this).

Try reading some articles on osmosis before making a decision, the money might be better spent elsewhere.

Nigel Clegg

David Pascoe

 

[Lakesailor]

[ QUOTE ]
get the bottom epoxied as prevention against osmosis.


[/ QUOTE ] You don't say that you have osmosis at the moment. Even if you have you could be wasting your money. If you don't have it do not bother. Of course the specialists and boatyards will recommend you do. It's work for them. Try searching for previous threads on osmosis. Opinions are mixed, but the reality is that most boats will develop it at some point and if you haven't got it yet don't start spending serious money on the off-chance. Even if it appears it's not as serious as boat owners have been led to believe.

 

[cpthook]

Be mindful that at some stage the osmotic hull will not dry out irrespective of the time of year. I read a surveyor's report where he suggested the blisters should be rubbed and left to "dry naturally". There reaches a point where the hull will refuse to dry, even if you dumped it in the Sahara desert.

At that stage (stage 3) it needs jet washing to purge all osmotic products. Only when it shows evidence of drying through regular meter readings can you stop washing.

I'm always a tad suspicious when I read about boats for sale that have been expoxied "as a preventative", but then perhaps I'm being a bit cynical.

Dude