The dreaded pox- whats the worst that could happen?

phanakapan

phanakapan

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So, I'm looking at old GRP boats 'cos I'm skint. I know, sure as eggs is eggs, that any so-called bargain will be riddled with osmosis. I've googled away and know that the options are 1) do nothing 2) treat individual blisters 3) strip, dry, treat whole hull blah blah blah.
So the question is, if I get something that looks like it's been bubblewrapped and take option 1- do nothing- what's the worst that could happen? (apart from not being able to sell as easily eventually).Just how many boats sunk/written off/lives lost are we actually talking?
 
To the best of my knowledge, no boat ever sank because it had osmosis.

I am in a similar position to you, and I bought a Westerly Nomad, she is totally clear of osmosis. A lot of older boats, say late 60's, don't seem to suffer with it, especially those that were built like a brick kasi, because they didn't know any other way to build them..........

It is true I think, that a lot depends on how the boat has been looked after, and particularly if she has been lifted out each winter, then less chance of osmosis being present.

Be interesting to see what others feel about this, and the above is just my opinion, for what it's worth.

Charlie.
 
Phillipa???

I just had a squint at your profile, and now am just a bit confused /forums/images/graemlins/confused.gif
 
Ditto. As a suggestion older boats were usually heavier built than later boats & thus even if the pox does strike, there is a lot more GRP between you & the oggin. Mine is 1972 & built like the proverbial, with so far no sign of pimples. It also spends almost all its time afloat as I'm too tight to bring ashore for the winter, & hate being stuck ashore on a good sailing day during the winter. You usaually get a good breeze & of course at least 50% of the other boats are ashore, so no traffic jams!! Best of luck getting a boat & enjoy it when you do.
 
Winter lift-out...

I've never really believed that lifting a boat out over winter in the UK will do anything much to reduce the likelihood of osmosis. With the low temperatures and highish humidity of an English winter climate, how much moisture is likely to be able to fight its way through a layer of gelcoat? Just consider the difficulty yards have getting a hull to dry out even after they've ground the gelcoat off! I reckon if a boat's going to get osmosis, it'll get it regardless of whether it's in or out of the water over winter. For what it's worth, mine stays in the water 12 months round.
 
Re: Winter lift-out...

Well, I have to be honest and say that I am with you on that one, mostly cos I am to mean to pay for a crane, and rent for a space, in somebodies yard!. I just put mine up on her winter berth, which is on the edge of the river bank, so she gets neaped, a lot.She is 38 years old, and no signs of the pox at all, so I don't reckon she is likely to get it now (legs crossed) /forums/images/graemlins/grin.gif
 
The worst: She won't sink but if you you try hard enough you'll come to the point where only a suicidal idiot would put her back in the water.
My boat didn't sink although, technically, she didn't have osmosis: the water got in through a porous gelcoat. She got left in for two winters running due to circumstances beyond my control and, when she came out of the water, the pressure hose took off the softened gelcoat as well as the barnacles. The yard then found how deep the wicking was (they used the analogy of rust on a cortina). That was in 1989 when she was 36 years old. Had her "done", and that was that.
Had I left her in for a couple of more years she may have softened all over and been irrecoverable, but I didn't and I'd hope she's good for another 40 years now. It's not an infection, it's a fault. If it threatens the boat, fix it and then she'll be alright. Don't, and it'll either get worse or stay the same, but it won't go away on it's own.
Hauling out every winter can keep the problem at bay, almost indefinitely, though.
 
A few years ago I was looking at buying a boat that had osmosis. Over most of the hull the blisters were quite small and not much to worry about. The surveyor noticed, however, that there was an area where the blisters were much more concentrated, and which was also a relatively hi-stress part of the hull (around the bottom of the rudder stock). His view was that the osmosis in this area, if left unchecked, could lead to local delamination and hence structural failure.

Was he being alarmist? Was I too easily put off? Who knows. I didn't buy the boat though.

Patrick
 
What, confused 'cos I'm a girl?? /forums/images/graemlins/crazy.gif
Oh, I see what you mean- the 40 foot steel project boat purchase didn't happen,(too much rust, no VAT, no paperwork) I'm looking for an intermediate get-me-and-partner- and-loads-of-kids-out-sailing type of boat, to use for the next 2-3 years. Then property can be sold and the liveaboard boat bought.
 
Re: Winter lift-out...

I took a bit long to type, so my post ended up after yours but I do beg to differ on the grounds of experience. True, with "pure" osmosis you may right, but lots of gelcoat faults end up with blisters or worse, and get labelled as osmosis. The layman cannot tell the difference, and I'm not so sure about most surveyors, but to be fair the original poster called it "boat pox" which is something of a catch all for these things. The fact remains that especially with an older boat, keeping her ashore out of season will help offset the ravages of time and reduce the spread of blistering. Of course, if there are no blisters in the first place then there's nothing to worry about.
 
What happened to the Folkboat? Always liked them, but no good where I am, everywhere dries out. Being a girl is ok, I have been around now for nearly 58 years, so have had time to get used to them, (note, I said used to them), I will never be able to understand them, as long as me arris point downwards! /forums/images/graemlins/wink.gif
 
Re: Winter lift-out...

My last boat had a few blisters when we got her, no problem. We took her out for 2-3 months in the winter whilst we had her, didn't notice much if any increase whilst antifouling etc. When our purchaser had her surveyed, the starboard side was covered in noticeable blisters, the port side had relatively few. The fouling had also been worst on the west-facing starboard side.
 
Re: Winter lift-out...

Dunno if I am right or not, I just feel that as you say, if you can keep 'em dryer in the winter months, you are probably helping to prevent any problems occuring? The owner before me, decided that seeing as she hadn't yet got any problems, he would have her epoxy coated to stave off anything happening in the foreseeable future, seems to have worked?

Do you think it's true, as some folk seem to think that boats kept in fresh water suffer with these problems more than those those kept in a salt water environment?
 
Re: Winter lift-out...

Still have a share in the folkboat; she's great. A group of people were doing a RYA course, but no-one actually had a boat, so they formed a syndicate and bought the boat for about £5000; it costs 200-300 a year per person to sail her. Only trouble is, one of the rules is no single handing, and trying to get together with the other members isn't always easy. Also our kids think she's too small and smelly!
 
Re: Winter lift-out...

My 1978 boat had a few small blisters when I bought her - but she had been kept in fresh water and the surveyor said that (a) they were not serious and (b) that in sea water, there was less risk of osmosis and the problem might diminish. And (so far, touch wood etc. etc.) he was right. I've had her for two years in seawater (also at Newhaven as it happens) and no recurrence at all.
 
Re: Winter lift-out...

Erm..............why is she smelly? She is a wooden boat? she should smell like a wooden boat? sort of all woody and varnishy? Somebody been doin' unmentionable things in the bilges?
 
Re: Winter lift-out...

Real osmosis is always going to be worse in fresh water, 'cos that's how the chemistry works. I remember seeing it in the gents in a pub many years ago, on the fibreglass "weeping wall". Not a pretty sight.
Personally, I think the trouble is that there are just so many causes of blisters, and so many differing patterns of use, quality of lay-up etc., that you can't predict anything. There are those who will tell you that epoxying a boat that hasn't been peeled and dried out will only seal in the moisture, and others who tell you that more gets in from the inside, through bilge water than ever gets in through the gel coat. I don't know who is right, but at least it gives us all something to talk about /forums/images/graemlins/smile.gif.
 
Wrong logic I\'m afraid - UK winters.

Immerse a susceptible hull in water and the ingredients for osmosis taking place are present. If fresh or brackish water even more so.

Take it out for 6 months and you immediately double the time it will take to make itself known. If it is damp and raining it will not dry out, but it will not get any worse.

However, in UK winters, sometimes for weeks on end, we get polar continental airflows which are as dry as a bone, and will dry rapidly anything in the way.

Hence chapped hands and lips, towels and underwear frozen solid but bone dry on the washing line, and damp hulls significantly dried out.

You are right about 'if a boat's going to get osmosis' in a way. If it has serious lay up problems it could occur within a season, or a few seasons if lifted out. But most hulls with standard polyester gel-coat will submit to absorbing water over time, and put on weight. If constantly immersed there is a chance that even the best hull will eventually succumb to blisters as absorbed water eventually finds something to dissolve and thus start the blistering process.
 
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