Sinkings due to osmosis

[Paul_on_a_Nic]

Has anyone ever heard of a GRP vessel sinking due to loss of structural integrity caused by osmosis? Is osmosis a genuine problem or just a gift to the lower life forms inhabiting the marine industry. A friend has had a rather negative survey, I say it's b****cks, what say you?

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by Paul_on_a_Nic on 21/02/2003 22:14 (server time).</FONT></P>

 

[clyst]

I did a thread on this a couple of weeks ago , I'v never heard of one yet !! nor has anyone else. Also discussed was how do you destroy a GRP boat at the end of its life ?.Didn't get an answer to that either!!
Hope you have better luck !!

cheers

Terry


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[seaesta]

I have never heard of any boat sinking or other failure due to osmosis

The yanks call it boat pox and seem to take it less seriously.

The only real problems seem to be the catastrophic effect on re-sale value and having the time and patience to grid out the blebs and fill them with epoxy once a flood.

Dont blame the surveyor blame the idle greedy gets that sue everyone all the time and make the surveyors cover their "rse and bump up everyones insurance premiums.

Martin (aka mr angry)

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[webcraft]

It's a manufacturer's nightmare . . .

GRP lasts forever.

Bet they wish they'd built them out of the same crap they build cars out of.

<font color=blue>Nick</font color=blue>
<A target="_blank" HREF=http://www.bluemoment.com>

</A>

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[Ohdrat]

That's why they keep changing (attempting to improve on) hull form..

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[l'escargot]

Compare it to cars. If you bought a 20 year old car, would you be suprised if someone said it had rust in it? Would you take it to a garage and let them convince you that it needed several thousand pounds worth of body work?
Assess the seriousness of the problem and treat it accordingly. if the only problem with the survey is a bit of osmosis, you're doing well.

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[sfh]

May i suggest that the problem effects only the saleability of the boat, there is a lot of choice out there so why buy one with a problem or indeed at full asking price.
once you own the boat in practical terms it appears to be less of a problem

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[byron]

<font color=blue>Osmosis is a Surveyor's dream because it gives them something negative to say about an otherwise perfectly good vessel. C'mon guys, a 20 year old steel commercial ship will be suffering from thinning of plates, a wooden vessel is kep alive by the dedication of the owner. Osmosis is a fact of life and apart from drastically reducing the value of a craft presents no risk of sinking.

<hr width=100% size=1>http://www.alexander-advertising.co.uk

 

[PaulJ]

I beg to differ..... Maybe 12 years ago a work collegue of mine bought and old stinkie (I think it was a Nelson) which had been lying unloved for years prior to that. He knew there was a lot of work to do when he bought it but not quite HOW much.... There were large areas of the hull which had completely lost their structural integrity and when dug out he had holes 2 ft across. He had bought the boat for a song so it was still economic to get these areas of the hull re-built. Ok, this was an extreme case, it was an old boat and had basically been left in the water for years without any attention however it does illustrate that if left untreatedfor long enough, osmosis CAN threaten the stuctural integrity of a hull.

It may be that your friend's boat only has a few blisters and that there is nothing to worry about at this stage. I know we are all suspicious of surveyors trying to justify their existence, but I found out the hard way that there is quite a lot to interpreting moisture readings in various parts of the hull. I also found out that surveyors vary enormously in their competence. It would probably be worth getting a second opinion from a surveyor who specialises in this problem..... if his brief is to survey only the osmosis and not all the other aspects which are normally covered by a full survey, it shouldn't be too costly. I don't know where your friend is based but in the South I would recommend Tony Statton-Bevan who does seem to know what he is talking about and gave me what turned out to be a very accurate assessment of the moisture content in a boat I was buying.... I have also recommended him to friends who have been very satisfied with his services.


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[colvic]

Just had a 9 page survey done at a cost of £400. By the time the disclaimers are removed, reasons for the survey, and "unable to fully inspect because of...." actual facts were down to 6 pages then about 11/2 were recomendations.

As you say, protecting ones rear!


Phil

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[jonjo]

Boats with bad osmosis can sink into obscurity in the corner of a boatyard because they won't sell and are not economic to repair.

It would be very difficult to document a case of loss due to osmosis triggered structural failure. Osmosis can reduce the strength of grp laminate by 10% but it would take a 360 degree roll in a force 10 before this became significant.

At the end of the day it comes down to psychology. Commercial operators can rationally deal with the rot/cost/time equation but who is going to spend £30k on a leisure item knowing it is progressively rotting and loosing strength?



<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by jonjo on 22/02/2003 10:35 (server time).</FONT></P>

 

[Trevor_swfyc]

Not heard of anyone ever sinking due to Osmosis but being told you have it must sure give you a sinking feeling.

Having a few pimples does not mean you have achne does it?

Trevor

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[ponapay]

It would be interesting to .

know Byron's qualification and expertise in making such an apparently sure recommendation.

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[extravert]

Looks like this one had the potential to even though it didn't. Look for the picture of the Irwin 65 Adventures of the <A target="_blank" HREF=http://www.xrayted.fsnet.co.uk>Teddy Bear Boat

 

[richardandtracy]

Never heard of one. BUT, it could be a significant contributory factor in an older boat - reducing the margins of safety during foul weather. Then if it sinks - the evidence is hard to get to. The natural conclusion will be that the boat was overwhelmed - no need for further investigation.

Basically I suggest moderation. Accept some osmosis as a fact of life, and don't get too bothered. Older (non racing) GRP tends to be thicker than it needed to be, so the likelihood of extreme damage due to osmotic weakening isn't very likely. Unless, of course, you enjoy force 10's.

Regards

Richard

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[Captgene]

There was a post regarding an improperly built Irwin 65 as reported by a surveyor in Florida. I looked at his surveyors website where he elaborates on most evey aspect of boat building and personal knowledge. Amazingly, if so knowledgable and a working surveyor, he had the time to write such long winded stories. One would think he wrote the book on surveying.
Problem is his report on the Irwin 65 building technique and laminate was mostly incorrect. Coring was not used below the waterline and chopped strand mat was used between 6 alternate layers of 24oz. woven roving.
I hate to see bad info and rumor passed around the world because other experts tend to read junk and call it fact.
Captgene web page