Different osmosis

fisherman

Well-Known Member
Joined
2 Dec 2005
Messages
19,675
Location
Far S. Cornwall
Visit site
Used to seeing osmosis, just sold my boat no problem, had osmosis since before I bought in 1992. The pimples, about thumbnail sized, and from one per sq ft to five or more. Never worried me, always thought 99% or more of gel is still attached, and surveyor agreed could be spot repaired if necessary. Insurance company said in their experience sometimes more trouble is caused by stripping and recoating. I've seen other similar cases, and one with blisters about 70mm diameter, not too good.
But this time I looked at a prospective purchase, the blisters very small, up to 5mm, but absolutely covered, looked a bit like anaglypta wallpaper. I wonder whether this would be more of an actual problem, certainly could not be spot repaired. (Given the depth of damage is in ratio with blister diameter). The moulding itself is a well known F/V make and very robust. Passed on the deal for that, but mostly other reasons.
 
Check this out:

http://www.europeanmarinesurveys.com/2014/06/pre-purchase-survey-what-is-osmosis/

I think what you are seeing there is Wicking. I have seen this on a boat in one quite small area, it did disappear after a month or so ashore, reappearing the following year. Note the comment:

"These swell with water and raise localised rashes on the gel coat which disappear after a short time ashore and usually of no consequence"
 
Top