Small pin holes - primer bubbles

[frilaens]

A couple of seasons ago I stripped the below-waterline hull to the gel coat and applied 5 layers+ of two component primer and then the anti-foul. This was done in an osmosis paranoia brought on by the increasing number of blisters appearing in the paintwork. As I began to remove the old primer and antifoul my opinion changed with advice from others and reading up a bit more. The previous owner had repainted and I suspect now that the primer wasn't applied in the right way or in the right environment. As I applied the new primer I noticed there were small pin holes in certain places which were really difficult or sometimes impossible to fill, using both a roller and brush. After the primer had dried some were always still visible. After lifting her this winter (after 2 seasons) I was pleased with the result except in one place where the primer had small bubbles that appeared over the space of an hour of lifting. There was no fluid in them, and they were maximum 5mm in diameter but raised a couple of mm from the surface.

Any advice about painting pin holes or the best way to repair the bubbles?

Thanks,

Andy

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[oldsaltoz]

G'day Andy,

Not sure if we are talking about the same thing, but a few years back I did a boat for a client, the Gel-Coat was full of bubbles, no visible until you start sanding.

This is caused by poor lay-up practice, too much in one go, and the Gel-Coat boils, the small holes have wax deposits making them very hard to cover.

If this is the case, you have a couple of options:
Grind or sand the area back and fill with closed cell Micro-Balloons, apply 3 coats of resin when cured, then paint and antifoul.
Or, Try washing the area with Acetone and plenty of clean rags, then coat with epoxy resin and paint, then antifoul.

By the way, I finished up removing all the Gel-Coat as the hull was showing signs of water damage, leaking thru the perforated (boiled) Gel-Coat.

I hope this helps.

Avagoodweekend......



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