RL24, RL28, and RL34 Trailable Yachts
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I have recently antifouled my RL28 and found a small number of osmosis blisters.

I understand the treatment for this hedious disease is to angle grind the blister out, allow to dry out (possibly with a hair dryer), apply an epoxy barrier such as Interprotect, fair the grinding with an epoxy filler then sand fair.

If anyone has had experience in treating this complaint I would be interested to hear your remedies and how successful they have been.


Nervious Navigator

Weak Knees10-Feb-2004    Edit    Delete 
repairing osmosis
I have watched hulls in boat yards being repaired after osmosis damage. After the effected areas were stripped of stuffed fibreglass, the hulls were left for 3-6 months to dry. A surveyor checked the hulls with a meter before the glassing repairs were started.

I do not believe a hair dryer or similar would remove the moisture from the deeper parts of the fibreglass matrix. It took a significant time for the hulls to dry properly.


Greg11-Feb-2004    Edit    Delete 
Re: Osmosis
You are dealing with a chemical reaction not simply a water soaked laminate.
No amount of time spent on hardstand drying out will have any effect on the elimination of Osmosis(correctly known by resin manufacturers as resin hydrolysis)
The condition is caused by up to 15% of the resin remaining uncured during manufacture and is exacerbated by poor quality control techniques.
Please refer to www.thermocure.com and attached links for further info.
Thermocure22-Sep-2004    Edit    Delete 
Re: Osmosis
I think I have an issue with Osmosis on Swan. From underwater inspections I see and feel some blisters and also a “crater” about 2cm across and 1-2 mm deep. The later really concerns me. I would like to slip and anti-foul Swan in a month or two but need to learn all I can re Osmosis first.
A search on this site has not found much useful info mainly this discussion from 2004. So I am wondering if anyone can add anything. I don’t plan to lay up the boat for months only a week at max.
I will look wider on the web and if I find anything useful will link it back here.

Russell Rogers12-Feb-2009    Edit    Delete 

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