Pinholes in Gel coat

[Alan1]

I have a 2002 Beneteau 311 which after having the old anti foul blasted off developed pinholes through the grp to the fibre glass matting. Does anyone know the solution to this .I am going to have her blasted clean again and epoxied to cover the holes.

Thanks for any advice or information given.

 

[Schuss39]

I went through a similar process earlier this year and used products from Reactive Resins based in Cornwall, www.reactiveresins.com

Have a hunt around their site for the various products and articles.

I used the Armourguard product on the keel, followed by the Safeguard range for the osmosis protection including the Easy Fair S filler product. Then finally the Synergy antifouling. As it was DIY it took time, far longer than I had expected! But so far looking good.

 

[sailor211]

I went through a similar process earlier this year and used products from Reactive Resins based in Cornwall, www.reactiveresins.com

Have a hunt around their site for the various products and articles.

I used the Armourguard product on the keel, followed by the Safeguard range for the osmosis protection including the Easy Fair S filler product. Then finally the Synergy antifouling. As it was DIY it took time, far longer than I had expected! But so far looking good.

That is the process I was going to recommend.
Good company excellent products. Time will tell of course. It is what I am using.
I am impressed with the armourguard I use on the keel.

Blast clean, easyfair , sand , safeguard tsf
It takes time, sanding 30 m of hull with an orbital sander is improving my upper arm strength at the moment.

 

[Concerto]

My Fulmar has suffered a similar problem. My surveyor said that Westerly double coated the gel coat but microscopic air bubbles were left in the gel coat and these are now bursting. According to a fiberglass expert, Westerly failed to brush out all the air bubbles from the mix before it set in the mould. I wonder if this is what might have happened with your gel coat. I know that production boats now have gel coat sprayed in the mould. It means the gel coat is very thin (like 0.5mm) and due to the spraying, is not a solid coat due to partial drying of the sprayed particles before contact with the mould. The fiberglass expert said this may become a problem in the future as boats age. Try and find out if your gel coat was brushed or sprayed.

My surveyor suggested that three coats of Gel Shield would hold moisture at bay. However, he also said that more bubbles may appear in the future due to the existing moisture in the hull, so more coats of Gel Shield would be a waste of money.