moisture levels

[Guest]

My GRP hull has slight signs of osmosis. I have removed all old anti-fouling and have bled a couple of isolated blisters. Can someone tell me what is an acceptable moisture content of the GRP before I consider priming the under water area for protection, prior to applying a new anti-foul.

 

[graham]

Hate to spoil your weekend but if the hull is showing blisters that can be bled then its allready well advanced osmosis.

If you intend getting it treated then dont paint anything on it as this will only have to come off again prior to treatment.

If you intend leaving it for now then the usual advise is not to open up the blisters or sand them off. Just leave well alone reantifoul and shop around for a yard that specialises in osmosis repair.

If you post your area then Im sure someone else can point you to a yard in your area that has given good service(or steer you away from a dodgy one!)

On the positive side it is highly unlikely to affect the integrity of the hull at this stage.So dont be rushed into anything.

 

[PeterGibbs]

Just to add to the above:

1. Have you had a surveyor look it over? Worth the small sum this would cost. You would also learn where best to take the hull for treatment if this need is confirmed.

2. If treatment is definitely required, and the affected area is substantial, you can kiss good bye to the coming season's sailing. You will also be into £2-4k of costs. It will take quite some time to strip, dry, and re-gel the hull. Depending on the surveyor's report, you might find a case for selling on the vessel now, even at an appropriate discount and especially if the affected area is small; osmosis is often considered more of a challenge than a death knell these days!

PWG