She has the measles

We have just gone through the same problem. If you look at this months PBO p46 you can see a couple of photographs. (My wifes thumb is now a celebrity!). After a lot of head scratching and asking around we went for the full treatment done by a professional yard. I'm not saying that that is the correct decision for everyone, but it was ours. The work involved was much greater than we had anticipated when we considered doing it ourselves; I don't think that we could have managed a full repair. One thing I do remember was the surveyor saying very forcibly was that we should not epoxy over problem as it would ony make things worse, rather than contain it. Our boat was lifted, for treatment to begin, on 4th July and has been back in the water for about a week now. Good luck!

Nigel

Good luck.Mine was out for a year having it done and it blisters back just after the 5 year guarantee ran out! Complete waste of 5k.
 
Does that mean that time out of the water isn't necessary? And what about epoxy coatings?

Sorry, LazyK, only just noticed your question.
No, time out of water IS necessary, I'm afraid. My point is that such time is of little use unless the hygroscopic elements have been removed by frequent aggressive washing. Equally, and as said by others, any barrier coat is counter-productive if it simply seals in the moisture (and the other products of osmosis, whoch will just carry on doing hat they were doing before): it should only be applied to a dry substrate.
Depending on the degree of the pox, that's not to say that a grind-out, fill and fair strategy doesn't often make sense.
 
That squares with our last yard who said they strongly discourage epoxy coatings on older boats, they saw too many where osmosis was the consequence, you're effectively negating the time out of the water. Is the latest thinking that if you're going to get osmosis you get it because of faults in the original layup, that there's nothing you can do to stop it and little you can do to encourage it?
 
That squares with our last yard who said they strongly discourage epoxy coatings on older boats, they saw too many where osmosis was the consequence, you're effectively negating the time out of the water. Is the latest thinking that if you're going to get osmosis you get it because of faults in the original layup, that there's nothing you can do to stop it and little you can do to encourage it?

Well my theory is that if you haven't got it, take every precaution to avoid getting it. I just bought a 1999 Westerly that had been out of the water for two years and was bone dry, so have just had the antifoul removed and had it epoxy coated.
 
I would have done the same except I wonder about the moisture in the gel coat - it got in there because of osmosis, it's only going to leave if you can persuade it that the air outside has a lower moisture content, which surely is never true outside of the Sahara?
 
I would have done the same except I wonder about the moisture in the gel coat - it got in there because of osmosis, it's only going to leave if you can persuade it that the air outside has a lower moisture content, which surely is never true outside of the Sahara?

Now that sounds a good cure. What about a business...sail the boat to West Coast of Africa, use camels to lug it to the desert. leave for two years, and sail it back home...

Could be a whole new business venture...

Mj
 
Hi MJ24

There is an excellent video on you tube of an American chap doing the complete job but no peeling. I think its the way I would go if/when it happens.
 
Now that sounds a good cure. What about a business...sail the boat to West Coast of Africa, use camels to lug it to the desert. leave for two years, and sail it back home...

Could be a whole new business venture...

Mj
Over here in the Summer a boat will dry up in a month ir two.
 
Again I'm puzzled about how the moisture gets out of the gel coat when the osmosis process has got it in there. When our cat was out for its pre-sale survey a few years ago the surveyor said the readings after three days out were effectively dry, he said after a year out it would be no lower. The trouble is there are so many millions made from osmosis prevention and cure that there's a body of received wisdom doing the rounds to support that industry. I'm not saying it's wrong, but there is a lot of vested interest. Just maybe it's all down to the original manufacturing process and you either get it or don't because of that. Once you've got it then I suspect the decision whether to peel or not is an emotional one rather than a logical one.
 
Osmosis is migration of usually water through a semi permeable membrane. The water molecules will migrate to dilute a more concentrated solution causing swelling on the concentrated side. At school we did an experiment with an egg with the shell dissolved in a beaker of water. The egg eventually exploded.
Its important to remove the solvents on the inside as they encourage the water molecules to migrate and to make the hull non permeable by applying an epoxy coating.
Or .... you can ignore it and carry on sailing.
 
I've seen two boats on the hard in Lagos, Portugal with osmosis. The blisters were ground out and heated drying pads were applied for a week, then checked with a moisture meter, a tarpaulin was over the boat to keep it dry. Then epoxy and gel coats were applied. It struck me that to be successful in fixing it you must completely dry the affected area and heated drying pads are the only way to do it.
 
She is Sadler 32.

I think she has been like it for a while, suspect it won't get worse, and hope the same.

Mj

Just had the surveyors verbal report.

Osmosis is definite. However, It is barley skin deep, ie the very outer layer is effected. Unlikely to get any worse, and not really any value in doing any significant repairs.

Phew....

Did recommend stripping the epoxy layer. And allowing the hull to dry out as best it can.

Apparently, the epoxy layers were only applied once, (a two part epoxy) whereas they should have be applied 3 times each. This has left the hull not so protected as it should have been.

There are several bigger blisters on the skeg and rudder. The blisters just need cutting out, washing severely and filling.

He pointed out that the boat was only a few years old there would be case for a full repair, but with a 35 year old boat, good money after bad.

Also commented on the high standard of building by Sadler.

Anyway been an education, and a interesting thread.

Thanks for all opinions experiences etc.

Mj
 
Top