Does osmosis matter ?

penfold

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The real problem is not the blisters, it is the foul-smelling ooze inside them. This stuff is usually acidic, and it slowly attacks the grp next to it, breaking it down to the consistency of shredded wheat. If blisters are discovered, treat them, don't ignore them; they only get worse and become more expensive to repair.

The best literature I have found on the subject is the book by Tony Staton-Bevan(available at Amazon last time I checked). <A target="_blank" HREF=http://www.yachtsurvey.com/>This guy</A> also has some sensible things to say about osmosis.

cheers,
david

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Delamination ....

There is Delamination where actual layers of GRP are coming apart ..... very rarely seen on boats hulls.

There is blistering that is normally between lay-up and gel-coat ... due to bad laying-up or voids etc.

It would be extremely difficult for de-lamination to occur at 90% etc. as this implies that similar %age of lay-up is 'dry' and un-resined. BUT 90% separation of Gel from lay-up can occur - but would be such an extreme case as to be literally unheard of.


<hr width=100% size=1>Nigel ...
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Now take this as stupid or what ....

Sometimes when partaking of an occasional Speckled Hen or Guinness ..... I consider the ways to traet a hull.

The thought of an industrial type electric plane set at slight depth to 'plane' the hull - similar to a peeler ......

Now the question is .... are they srong and lasting enough to work with the gel ? Would it 'grind' to a halt .... sorry about the pun !

Anyway just a drunken thought !!!!


<hr width=100% size=1>Nigel ...
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Suggest you look at Int. Paints guy

Or the guy who backs up the Tramex with real authoritive info.



<hr width=100% size=1>Nigel ...
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Blue_Blazes

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<<There are two types of boat...one's with osmosis, and one's that are going to get it.>>

Not so, I'm glad to say. My wooden boats will never get it. Ok so they might rot instead. Steel boats can rust too. Basically what I'm saying is osmosis (like sh*t) happens. Unless it's a VERY serious case, and likely to cause structural failure, I wouldn't worry about it too much.

Bill.

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richardandtracy

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Re: Delamination ....

Yes, but in exterme cases of osmosis the water wicks along the fibres separating the fibres from the resin. This is delamination too - not a commonly identified cause of laminate degradation, but it makes the laminate into a useless mush with negligable useful strength. The problem can be that the resin is still intact, so under light loads you can't identify it by pressing on it. This, I feel, is the more insidious and dangerous side to osmosis.

Regards

Richard.


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