Osmosis treatment

[jbate]

I suggest that you go back and ask the surveyor to explain why they said the Osmosis is in final stages and what they mean by this. What are the recommendations in the survey report, how urgent does the surveyor think that the osmosis issue is? Give the surveyor the chance to explain the reasoning behind the commets...
Do you have any photographs? What were the moisture meter readings and how long had the boat been out of the water..?
JB


<hr width=100% size=1>

 

[Heckler]

Firmhelm pwlhelli

quoted me last yr approx 4k to do a trident voyager 38, put the above in google and do a search for their number, simon is the name to ask for
stu

<hr width=100% size=1>http://www.beneteau-owners-association.org.uk

 

[poter]

No! all boats over 20 years do not get Osmosis, in fact there is a very good argument for buying an older fibre glass hull as the resin quality was higher.

I was in the same position as yourself about a month ago, regarding osmosis on a 26 year old 30' Moody.
I had a very well qualified surveyor who stated "In general the hull has a low to moderate moisture content....At this time isolated areas of light blistering were noted at the lower stem area.... indicating an early stage of Osmosis"

As soon as I saw the dreaded word I went to a few people to get quotes for "osmosis treatment"....The vacuum bag and heaters was quoted as the only way to permanently get rid of Osmosis.....but surprise! no guarantee. In fact I could not get any sensible guarantee with any of the boatyard Osmosis treatments.
I then started to ask a few questions of the local boatyarg guys around Plymouth & on the forums and I eventually came to the conclusion that there is no one answer, to the so called Osmosis problem, yes plenty of supposed expert advice & anecdotal stories, but no real facts, even from the large paint manufacture’s, again plenty of advice on how to apply products and preparation of the hull…. BUT not one could answer the question- ‘At what state of blistering should a treatment be done and how long will it last’

This site: http://www.yachtsurvey.com/moreonblisters.html.htm
By David Pascoe has, IMHO some well researched evidence on what happens to fibre glass hull’s and even some advice, sample as follows:
“No, the moisture meter isn't going to tell you whether a boat is likely to get blisters or not simply because most boat hulls are saturated with water. The reason why some blister and some don't is basically a matter of quality materials and good techniques. Even when saturated with water, quality hulls are far less prone to blistering”
I read this and the balance of the articles on the site & because it was mostly common sense I changed my idea’s on what to do with my Moody.
In the end with the help of an ex Marine Projects engineer all I did was scrape the hull and apply a good quality antifoul. Saving between £4000 & £5400.
Ok its my risk, but as there was little or no blisters and I would rate the mid 70’s Moody’s as a quality build, the risk is certainly not excessive even if I don’t lift out every year.

I am afraid no one can give you absolute factual advice but I would certainly do the research, have a list of questions to ask the boat yards & do read David Pascoe’s site.
Good Luck let us know how you get on.

By the way Shady Lady is now back in the water with her new tcut and polished hull and looks just great, not bad for a 26 year old Gel Coat.

poter


<hr width=100% size=1>

 

[brianhumber]

If this 'final stage' is just based on some water content reading your man is either going by this which I would argue is a wrong conclusion or he is basing his argument on the fact that all GRP boats of this age are likly to develop Osmosis. Has he perchance offered to oversee the 'treatment' ?
I smell rotten rats in the final stages of decomposition but then I am a cynical old git.

<hr width=100% size=1>

 

[oldgit]

Not all craft over a certain age have osmosis and www.yachtsurvey.com is an excellent place to get information.
While looking at a 1975 35ft grp Pegasus (Cox and Haswell)a while ago the survey indicated a high water content.Apon querying this with the surveyor he commented not to worry about it as the hull would last a lot longer than me.
My present boat a 20 year old,princess has no detectable blisters anywhere on hull despite my best efforts to find some.The boat has been afloat for all this time apart from a year ashore before I bought her.
Early GRP hulls seem to be much better built than the cost cutting hulls that came after.

<hr width=100% size=1>If it aint broke fix it till it is.