Fiberglass Repair under water line

stingray165ss · Mar 17, 2013

Hey guys, quick question here. I have a 1986 stingray svb 165ss and i had to patch a hole on the keel. I bought the Bondo fiberglass repair kit from walmart to do this. The question i have is will the fiberglass be waterproof without any kind of gelcoat or paint on it. the hole is about 1" long but i sanded the down to fresh glass about 2" up on the side and 4" down the keel. I know i probably should have cut a hole in the floor and repaired from the inside but i really didnt have the time. i just need something to get me by a few years. Do you guys think this method will work. It seems pretty hard. If the fiberglass is not waterproof what do i need to do. Gelcoat? coat it with epoxy? or just some good ole paint. thank you so much.

Tjdello · Mar 17, 2013

Re: Fiberglass Repair under water line

I would put about 3 layers of marine paint then one layer of gel coat just to be safe

jbcurt00 · Mar 17, 2013

Re: Fiberglass Repair under water line

Tjdello said:
I would put about 3 layers of marine paint then one layer of gel coat just to be safe

I don't think you want to apply gelcoat OVER paint, marine or any other kind. Perhaps the other way..........

Gelcoat 1st, the color will be difficult to match REALLY well, then paint. But you'll need to paint most or all of the hull.........

stingray165ss · Mar 17, 2013

Re: Fiberglass Repair under water line

thanks for the replies, the color is not important to me at all, it is on the keel so its below the waterline, why will i need to paint most or all of the hull? what is a good gelcoat kit for such a small area? and do you think this method will be strong enough. the only reason there is a hole in the keel is because the previouse owner was pulling the boat up on the trailer with a broken keel roller and the bracket for the roller was hitting the keel.

jbcurt00 · Mar 17, 2013

Re: Fiberglass Repair under water line

A pix would help.

Think of your repair as a rust repair on a fender...... After the repair, you really need to paint the whole fender, or the patch job paint will show, & eventually fail along it's edges....

Water does generate friction & drag, so eventually, if you only spot paint the repair, IMHO the paint will peel......

stingray165ss · Mar 17, 2013

Re: Fiberglass Repair under water line

i will try and post some pics tomorrow, i still have to get out there and sand it down. I really appreciate the help. I think i am going to gelcoat it, i just have no experience with gelcoat.

jbcurt00 · Mar 17, 2013

Re: Fiberglass Repair under water line

Check his current build, lots of great gelcoat info:
[h=3]Friscoboater's 1986 Glastron Carlson CVX-18 Complete restoration [/h]
And look thru his other builds & youtube channel.

Here's 1 kit sold by iboats (currently on sale):
Gel Coat Repair Kit - Evercoat 108000 - iboats

stingray165ss · Mar 17, 2013

Re: Fiberglass Repair under water line

thank you, I have watched frisco boaters videos on you tube, he really is dedicated and does amazing work. I will have to watch some of his gelcoat vids.

Friscoboater · Mar 18, 2013

Re: Fiberglass Repair under water line

I really enjoyed doing the gel coat repairs. To me it is easier to deal with than paint. You can almost just brush it on thick, sand it flat, and polish.

pauloman · Mar 18, 2013

Re: Fiberglass Repair under water line

the polyester resin and glass is much more waterproof then gel coat which is just pigmented and thickened polyester resin. That is way some boats get blisters below the water line. It is water getting through the gelcoat and collecting between the regular resin and the thickened gel resin.

paul
progressive epoxy polymers inc

Friscoboater · Mar 18, 2013

Re: Fiberglass Repair under water line

pauloman said:
the polyester resin and glass is much more waterproof then gel coat which is just pigmented and thickened polyester resin. That is way some boats get blisters below the water line. It is water getting through the gelcoat and collecting between the regular resin and the thickened gel resin.

paul
progressive epoxy polymers inc

So true. I always wondered why fresh water boats that sit in the water have bottom jobs.

stingray165ss · Mar 18, 2013

Re: Fiberglass Repair under water line

So the polyester resin is that what i used for the fiberglass? Does that make the fiberglass waterproof without any paint or gelcoat

Fiberglass Repair under water line

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