Gelcoat lifting

[jim99]

I have hauled and am preparing to paint the topsides of our Vancouver 27. I thought the paint was cracking and lifting near the waterline at the bow, but on closer inspection it appears that it is the gelcoat that has split in a few places. There are also 8-10 blisters under the paint midships, each about the size of an egg yolk, and I fear it is the gelcoat lifting, but haven't cut into it. Below the waterline, there is not obvious problem.

Friends tell me that I may have to remove all the gelcoat, which is a scary prospect. Surely I can just repair it. Wondering if anyone here has had a similar problem, if removing the gelcoat proved necessary and what is involved.

Also, can temperature affect gelcoat? Our V27 was built by Pheon, shipped and launched in Singapore in 1979. I bought it in Thailand in 2001, and sailed near the equator for almost 10 years before we sailed it north and home to Victoria, BC. Maybe a coincidence, but we never had a problem with the paint or gelcoat before we sailed north, when it started to crack.

 

[nimbusgb]

You can patch and repair each section with flocoat ( gelcoat with wax added for application outside a mould )

Remove all the loose material, sand back an feather the edges, fill with flocoat, building up the layers, sand and polish. You may need to colour match your flocoat.

The egg sized blisters could be osmotic ( filled with dark smelly liquid ) remove damaged material and grind or sand our the blistered area, dry thoroughly rinsing frequently with acetone, fill and repair locally.

This is a 1979 boat, unless you want to spend megabucks you can fix locally.

 

[Avocet]

I've had a failed gelcoat. It's not nice! Like you, the underwater surfaces were fine (epoxied) but the topsides were crazed. No blisters, but still failed. I think the OP's boat is painted? If that's the case, then I agree with nimbugsb - do a local repair. All I would add is that if you can see some egg yolk-sized blisters, you will almost certainly find additional smaller defects along the boot top area as you start looking. IF so, you might be as well stripping the whole gelcoat off for (say) 6" above the waterline and replacing it. You might also find it has "wicked" down below the waterline slightly in places. Also, if you still intend to keep the boat painted, I'd probably not use polyester gelcoat / flowcoat again, but would be inclined to go with epoxy filled with microballoons - which is much more impervious to water, sticks better to the original laminate, and is relatively easy to sand - then just repaint.

 

[jim99]

Thanks for the replies and advice. Yes, she is painted, and has been for about 20 years, 10 years before we bought her, and has a thick wafer of old paint. Nothing to do but begin the job.