gelcoat repair advice

[used2sail]

My boat was hauled for the season recently and i went and cleared all my gear off earlier this week to bring home and store for the winter. While looking at the hull i noticed this chunk missing right on one of the underwater strakes. I don't know how i managed to do this but my bet is a lobster bouy that i missed and then ran over. What is the recommended repair technique for this type of damage? I'm assuming Marine Tex but i'd like to know if there is a better technique.

 

[seasick]

Do I see fibers exposed or just resin over fiberglass? If the former, to do the job correctly you should get a qualified glass person. If there are no exposed fibers, you can go the cheap route and use MarineTex and then bottom paint.

 

[DennisG01]

Marine Tex (or PC-11) will be fine. Although not "needed", a better solution would be to do a quick coat or two of epoxy resin and then thicken the epoxy to finish it off. Grind it out a little bigger, first. Polyester resin would be fine, too - it's less expensive than epoxy, but epoxy is easier to work with.

 

[seasick]

Marine Tex (or PC-11) will be fine. Although not "needed", a better solution would be to do a quick coat or two of epoxy resin and then thicken the epoxy to finish it off. Grind it out a little bigger, first. Polyester resin would be fine, too - it's less expensive than epoxy, but epoxy is easier to work with.

We are going to get into the epoxy over resin discussion

 

[Hookup1]

Do I see fibers exposed or just resin over fiberglass? If the former, to do the job correctly you should get a qualified glass person. If there are no exposed fibers, you can go the cheap route and use MarineTex and then bottom paint.

I would follow SEASICK's advice. I would repair this with epoxy and glass cloth. Sand off 1" of the bottom paint around the repair. Build it up and sand it to match the hull. Give it a finish coat of thickened epoxy or epoxy fairing compound. Finish sand it.

 

[used2sail]

I've done a little work with fiberglas cloth and resin years ago patching holes in beaters I owned in my younger years. would the woven cloth or the "tiger hair" style cloth be the preferred cloth ? also how does one "thicken" epoxy to use for this repair?

 

[DennisG01]

I've done a little work with fiberglas cloth and resin years ago patching holes in beaters I owned in my younger years. would the woven cloth or the "tiger hair" style cloth be the preferred cloth ? also how does one "thicken" epoxy to use for this repair?

It's such a small area that it really doesn't matter what cloth (if any) that you use. You're going to be cutting it up into really small pieces. But sure you can use Kitty hair or Tiger hair INSTEAD of epoxy/cloth. Kitty/Tiger hair is not cloth - it's pre-mixed epoxy resin with strands of glass already in it. But I'd use short-strand filler instead of the long-strand since it's such a small area.

Truthfully, you can thicken it with anything you want. There are specific thickeners that you can buy such as silica - but you can use baby powder, sawdust... whatever. The silica will be a little nicer, though, to work with... but BE careful when mixing - it is feathery light and you don't want to inhale it.

 

[seasick]

Visit Boatworks Today on you tube and search for videos on hole repair etc. The videos you will benefit from are several years old.

 

[DennisG01]

Another way to fix this, if you're not worried about matching the final shape (which is fine - it won't affect anything) is to just throw a few coats of epoxy on it, about 10 minutes apart from each other to let the first coat sink in. That will completely waterproof the area. I'd sand it a little smoother first, though. This method would be 100% functional - just not 100% aesthetic - but it's such a small area it really wouldn't matter. But that's 100% your call

 

[seasick]

Another way to fix this, if you're not worried about matching the final shape (which is fine - it won't affect anything) is to just throw a few coats of epoxy on it, about 10 minutes apart from each other to let the first coat sink in. That will completely waterproof the area. I'd sand it a little smoother first, though. This method would be 100% functional - just not 100% aesthetic - but it's such a small area it really wouldn't matter. But that's 100% your call

Using MarineTex would be a similar fix and can be purchased in white color. Since the area will be bottom painted, the color doesn't matter till someone sands the bottom paint off.

 

[OceanSun]

In my opinion many of these answers, although not at all wrong, seem to overcomplicate the issue and repair.

From the pic it does not seem to be a structural integrity issue rather a nice divot in the gel coat down to the glass. If it were my boat I'd use MarineTex prepping the area by sanding back the bottom paint a bit (don't dig into the gelcoat while doing so) and grind/sand any loose gelcoat chips, etc. away. I'd probably do two coats of MT with the first filling the hole and the second overlapping the good gelcoat by 3/4 inch or so. You should be able to get it pretty smooth with just your putty knife to minimize sanding. While sanding start with a courser grit to shape it down if needed and then move to a finer grit. Since this will be bottom painted no need to get super fine as you would with gelcoat. Let it fully cure and then touch up the bottom paint and you're good to go.

 

[Hookup1]

Epoxy is waterproof and will stick better to the polyester resin the boat hull and gelcoat are built with. You can't just use epoxy - it's too hard to sand. You need to be careful what filler you use to thicken the epoxy and improve sand ability. I use AwlFair epoxy as a pre-thickened two part fairing compound. Problem is you would need to buy a quart of base and a quart of converter.

TotalFair is a similar product. Available in two pint kit.

Since it will be bottom painted the color of the repair doesn't matter.

 

[used2sail]

Visit Boatworks Today on you tube and search for videos on hole repair etc. The videos you will benefit from are several years old.

Thanks for suggesting this channel. I just watched one video and i feel like i know more about boat fiberglass than i have learned in my prior 59 years. This looks to be a great resource for technique and what i really like is he gives you the correct materials to use fro each type of repair.

 

[seasick]

The site has a lot of info but more importantly, when Andy makes a mistake and he does every now and then, he admits it and includes it in the video. The video was one of the more informative and enlightening was the one on matching gel coat color.

 

[Fishtales]

I think the marine tex is fine for that. Easy fix, mix, apply, sand smooth and bottom paint.

 

[Rustygaff]

Take Fishtales advise and keep it simple. No need to go down the overkill rabbit hole.

 

[Fishtales]

BTW, that strake/chine is 100% glass - no wood or composite there. I'm gonna be honest, I've seen a lot of these type of damages on boats that are racked or during in/out moves. It happens more frequently than you think. If the dealer notices it, they usually fix them and re-bottom paint. When you experience your first, you likely get upset and ask a lot of questions. With time you accept that fiberglass is easily repaired and such dings and bangs are part of the boat experience. If your really concerned, you can have a pro fix it.

 

[DennisG01]

BTW, that strake/chine is 100% glass - no wood or composite there. I'm gonna be honest, I've seen a lot of these type of damages on boats that are racked or during in/out moves. It happens more frequently than you think. If the dealer notices it, they usually fix them and re-bottom paint. When you experience your first, you likely get upset and ask a lot of questions. With time you accept that fiberglass is easily repaired and such dings and bangs are part of the boat experience. If your really concerned, you can have a pro fix it.

Agree.

 

[used2sail]

BTW, that strake/chine is 100% glass - no wood or composite there. I'm gonna be honest, I've seen a lot of these type of damages on boats that are racked or during in/out moves. It happens more frequently than you think. If the dealer notices it, they usually fix them and re-bottom paint. When you experience your first, you likely get upset and ask a lot of questions. With time you accept that fiberglass is easily repaired and such dings and bangs are part of the boat experience. If your really concerned, you can have a pro fix it.

well maybe that wasn't something I did. The boat got pulled before hurricane Lee. They pulled virtually every boat in the marina in 3 days and i did notice some abrasions on the gunnel from the pull.