Is Osmosis Prevention a Good Idea?

[Idle]

Hi,
I have a 2002 built Jeanneau Sun Odyssey. I am the first owner and she is in water all the year around except antifouling painting periods.
There is no sign of osmosis by inspection.
Moisture is not measured yet. If the moisture measurement is
at acceptable levels, I am dubious whether to do an osmosis prevetion shielding.
The advice are equivocal:
One argument:
- The boat is getting old. Be on the safe side.
- Prevention is cheaper than treatment.
The other is:
- You are preventing an obscure threat. It may never happen.
- You may harm the gelcoat during the process and do cause the
trouble.
- Wait for early signs of osmosis, if it happens
get the damaged site treated while the rest is shielded.

Although both sounds logical, what is the real answer?
Idle

[Cheechako]

At the point where you want to remove all bottom paint and start over, I would put protection on. Once the water gets in to the glass, the fix is big.

[denverd0n]

There isn't any "real" answer. There are different options and you've been told what they are. Personally, I would take option #3, wait for signs and then fix/treat. It's really your choice, though.

[neilpride]

Yes is a good idea , if you wait until a blister show up , is the start of the problem, if you do it now, you can delay a future osmosis scenario or worst..
3 or 4 coats of Interprotec do the trick....

[psneeld]

Read well beyond the scope of these forums....most boaters (even guys who repair blisters) have only tidbits of the story.

Last year I ground off my bottom in places up to half of the layups that had delaminated from hydrolysis. I spent a year of concerted effort (retired liveaboard) researching the problems and fixes.

While true your boat may never see a serious threat...you need to know what resin your
hull is made of, the amount of moisture in your hull already and if you are willing to dry it out properly prior to any barrier coating because if you don't...you may be aggravating the problem.

Some "experience in this field" feel that once the process has started...because of several factors involving your particular hull...and how you use that hull...you can't prevent blistering/hydrolysis from happening...all you can do is slow the process (of course if you strip off half the hull and add back a new hull then sure...you might eliminate it for your lifetime).

[cal40john]

Same consensus that you got from other research on websites.

While (true) {Yes, no}

[psneeld]

Originally Posted by cal40john

Same consensus that you got from other research on websites.

While (true) {Yes, no}

If directed at me...I don't understand what you are asking/pointing out.

The vast majority of my research wasn't from forums...and a lot of it wasn't even in the marine field. The marine field generally seems in the dark ages about hydrolysis and osmotic blistering...both cause and prevention.

The fiberglass storage tank and piping business has surprisingly a lot of technical research available online and only a phone call away.

[barnakiel]

I would not touch it until there is a sign of osmosis.

If you have good meter, measure her next time on dry. Just follow the whatever is supposed to be the dry out delay and DO NOT let the job to your local osmosis prevention specialist...

b.

[neilpride]

Originally Posted by barnakiel

I would not touch it until there is a sign of osmosis.

If you have good meter, measure her next time on dry. Just follow the whatever is supposed to be the dry out delay and DO NOT let the job to your local osmosis prevention specialist...

b.

Well, a sign of osmosis is to late, the only cure for a osmotic hull is peel and dry, big pain in the ass $$$$ ...

Sanding the old antifouling to bare gelcoat and putting some coats of barrier coat is not a big deal, it take in our boat a long full week job between my wife and me, almost 3 dirty days for the antifouling, aply the barrier coats is a piece of cake, 1 coat in the morning , 2 noon, next day same and new antifouling ... Ours choice is for Interprotec 2000e, cool product... Thats why is called preventive barrier coat,

[robert sailor]

2002 you would think that the builder used vinylester resin for the first layer and if so I'd leave it alone.

[Jim Cate]

It might be worth your while to research the fate of sister ships of the same vintage. Some models and years seem better than others, even within the same marque. Might give you some idea of what to expect.

But if it were me, I would not do the preemptive strike... fixing early blistering should it ever appear isn't that much more work than what you are facing with the before-hand efforts.

I owned three conventional FRP boats (Catalina, Yankee and Palmer Johnson) and none of them ever developed blisters. I was, therefore glad that I hadn't wasted my efforts in preventative work. I suspect that I was lucky.

Cheers,

Jim

[barnakiel]

Originally Posted by neilpride

Well, a sign of osmosis is to late, the only cure for a osmotic hull is peel and dry, big pain in the ass $$$$ ...

Sanding the old antifouling to bare gelcoat and putting some coats of barrier coat is not a big deal (...)

Sure no big deal much as I know some people who claim you must peel the gelcoat too. I do not say I agree with them, but they must be basing their opinion on something (?) They also say you must dry the hull first. Drying can only be done in specific climate or else with help of pretty expensive hardware.

What I will disagree with though, is about 'sign' being 'too late'. Have seen dozens of poxy boats peeled and epoxied.

Fixing something that is not broken may be some sort of sailor's adhd. ;-)

b.

[neilpride]

Originally Posted by barnakiel

Sure no big deal much as I know some people who claim you must peel the gelcoat too. I do not say I agree with them, but they must be basing their opinion on something (?) They also say you must dry the hull first. Drying can only be done in specific climate or else with help of pretty expensive hardware.

What I will disagree with though, is about 'sign' being 'too late'. Have seen dozens of poxy boats peeled and epoxied.

Fixing something that is not broken may be some sort of sailor's adhd. ;-)

b.

Ohh Brnie, i think we mix the isue , i believe the Op is asking for info about a preventive barrier coat job, Primer in my book, preventive barrier coat is just simple epoxy primer over gelcoat or over epoxy, if we talk about a complete peel and epoxy coating hull, yes i agree with you, until some sign of osmosis or whatever,

[sailorboy1]

To me this falls into the "don't fix what isn't broken" world. You barrier coat IF you strip the hull paint for something else, but you don't strip the hull just to barrier coat (on a modern boat).

[neilpride]

Don, its a 2002 sun odyssey, barrier coats are ok in new or old boats , and yes lots of folks strip the old antifouling to barrier coat and renew the antifouling, boatyards are full of boats striped of old antifoulings...