Fiberglass hull repair?

[GordMay]

Originally Posted by Jdege

The hull of my boat has a fairly deep gouge in the hull where someone scraped along some rocks ...
... I've never worked with polyester, though I've done a bit with epoxy, and I have some West Systems 105/205. Can I do the repairs with epoxy? ...

West System produces some of the clearest technical info anywhere.

WEST SYSTEM* Epoxy Resources ➥ https://www.westsystem.com/instruction-2/

Including Boat Repair ➥ https://www.epoxyworks.com/index.php...s-boat-repair/

Projects ➥ https://www.westsystem.com/projects/

* WEST stands for Wood Epoxy Saturation Technique, a wood-epoxy composite boat building method, used by company founders Meade and Jan Gougeon.

[Manateeman]

The crew is solid on the recommendations of Frankly. No bondo, no mishmash.
1708 in epoxy. We think the real issue here is water. You don’t want to seal in any water. Do everything you can to keep any water from getting into the repair as you do it and be sure no water is already in any of the layers of the hull layup.
The manatee crew

[Jdege]

Originally Posted by Manateeman

We think the real issue here is water. You don’t want to seal in any water. Do everything you can to keep any water from getting into the repair as you do it and be sure no water is already in any of the layers of the hull layup.

The boat's been on the hard since September.

It'll be another month before it's warm enough to repair. I'll cover it in plastic my next trip to the yard to keep any rain out.

[JBP]

Regarding barrier coat, yes it's the currently recommended process because it helps prevent water absorption when a boat sits in salt water 360/365 days a year. You are in fresh water and seasonal. Your boat gets 6 months to dry out every year, so meh. If you want to do it "right", an epoxy based barrier coat over your final faired patch and the bottom paint will give you satisfaction of a job done right, however you will probably never notice if you skip the barrier coat.

[JBP]

Regarding 1708, I'm not as enamored with it as some. For multiple layers I dislike having the CSM in each layer. It's not necessary and sucks up resin making your glass to resin ratio worse. You only need CSM for smoothing rough surfaces, but you are going to grind it smooth first, and then fair it afterward.

Also 1708 is very thick for small jobs. I prefer 10 oz cloth or 12 oz biaxial (1200) for smaller jobs.

[Jdege]

Originally Posted by JBP

Regarding barrier coat, yes it's the currently recommended process because it helps prevent water absorption when a boat sits in salt water 360/365 days a year. You are in fresh water and seasonal. Your boat gets 6 months to dry out every year, so meh.

I don't have plans, I have vague intentions. By my intent is to get this down to the Islands.

I'm thinking about sanding her back and applying new barrier coat, before I put on antifouling and put her in saltwater. So I may not bother applying a separate barrier coat over the patch. Ordinary epoxy makes a fair barrier coat as-is.

[Jammer]

Originally Posted by Jdege

It'll be another month before it's warm enough to repair. I'll cover it in plastic my next trip to the yard to keep any rain out.

I wouldn't wait. Pick a dry, reasonably warm day to get the epoxy on, then just wait for it to cure. The fast hardener (for WEST) will work down to around 45 degrees according to the literature. It will take a long time to cure in the cold but it will cure eventually.



The yard you're at sells WEST epoxy at the same prices as everywhere else, and Alan is knowledgeable and has good advice. There is power in the yard. If you ask he will generally let you plug in for spring maintenance.

[Jdege]

Originally Posted by Jammer

I wouldn't wait. Pick a dry, reasonably warm day to get the epoxy on, then just wait for it to cure. The fast hardener (for WEST) will work down to around 45 degrees according to the literature. It will take a long time to cure in the cold but it will cure eventually. .

Not going to have dry, reasonably warm days for a while.

We don't just need to reach 45, we need to stay above 45 long enough for it to cure. 10-day forecast suggests we'll get up to 50 on Saturday, but the low that night is 37, and a couple of hours in the afternoon won't cut it. There are no days in the 10-day forecast with lows above 45.

And right now I don't have room to work; the boats are packed in too closely. They've not yet started splashing the boats. There's still ice in the harbor.

Oh the joys of Minnesota in April.

Won't be long, though. In the meantime I'm replacing the standing rigging and I am doing some work in the cabin.

[Rumrace]

Someone must have said Systems West by now.

Check further down the hull for pox. Water will migrate and find a void to collect. If you find any drill them out and repair at the same time with Epoxy. Add some micro balloons to the Systems West and use a 1 pump batch at a time. You can match gel coat and apply on top of West or prime and paint. Water sand only 220, 320, 400 constant flow of water and west comes out like glass.

[Jdege]

Originally Posted by Rumrace

Someone must have said Systems West by now.

Check further down the hull for pox. Water will migrate and find a void to collect. If you find any drill them out and repair at the same time with Epoxy. Add some micro balloons to the Systems West and use a 1 pump batch at a time. You can match gel coat and apply on top of West or prime and paint. Water sand only 220, 320, 400 constant flow of water and west comes out like glass.

There are some shallower scrapes, further down, but there are no blisters.

She's been in Minnesota for the last 25 years - cold, fresh water, and on the hard six months/year.

When I get her down to the gulf I'm going to need to scrape off the VC-17, and I'm thinking I'll probably replace the barrier coat then, but I don't think it'll be an issue until then.