TOPIC: What to use to fix fiberglass hull crack

About 10 years ago, the hull on my boat was patched by an auto body shop from too long of bolts being used for the seats. Occurred in 3 spots, patches are about 1" square. I noticed one of the patches which is a hard plastic fell off. The auto body shop that did the repair is very busy and my boating season is about over. Is there a way i can do the repair myself? I attached a couple pics. It is below the waterline.

That is a pretty simple repair requiring so simple tools and while you are at it you might as well go ahead and fix the other two holes.

With a Dremel Tool or other small sander/grinder carefully grind to area back an 1-2 inches to good solid glass. Rough up the Gel coat a bit with 80 grit paper and wipe it all down with Acetone.

Using a Chop Strand (available at auto parts stores in a kit with resin, Bondo brand) and see if you can get a small piece of fine fiber glass cloth. Cut layers of glass like a Topo Map with a layer the fit inside the hole and slowly getting larger working the glass matte in wet layers into each area....No Bubbles between layers, layer 2-3 layers and let cure, lightly sand with 80 grit paper and add additional layers until the area is built up to just above the Surface of the gel coat.

Sand back to the Gel Coat and apply some sort of Bottom Coat or other marine sealer to seal and finish the repair.

Good Luck,

Karsten

Thanks for the info and taking the time to write it, very informative but just not quite following. Is this something that takes weeks to do and are you saying to take the small crack that is there now from the puncture and make a large 2" diameter hole the whole way thru? That just scares the heck out of me. I have never worked with fiberglass before and can't find any youtube videos for something like this (do you know of any?). Would hate to learn on something so critical. If i could find somebody to do it for me, i would. I was hoping there was something out there similar to the other repair done, smear in some epoxy or JB weld and put the patch on it and back to fishing. Is there anything simple like this that will get me back on the lake til i find somebody to do it? There might even be wood to deal with behind the fiberglass, i can't see it from the inside.

Sorry......Don't make the holes any bigger.....grind and sand back to good Glass and Gel Coat leaving the wood intact (unless the wood has been wet and rotted. Just a simply Screw Hole don't remove any good wood just Gel Coat and back to good solid Glass.

You can try Marine Tex....Water Proof Epoxy.



Karsten

So i grind the surface back enough to get rid of the cracks in my pic, then lay in little layers of fiberglass? If i grind the surface back, before i do the fiberglass, what do i stick in the hole itself? I am working from the bottom up. Didn't get to watch the video yet. Thanks.

Checkout www.boatworkstoday.com . There are how- to videos on fiberglass repair and painting etc.

You are getting the idea....grind/sand away all damaged Glass and gel Coat trying not to take away much wood.

here is another Video.

So if i grind back the spauling gelcoat and loose fiber, can i just buy fiberglass resin with a hardener and use a syrenge to try to get it into the hole. Then put fiberglass resin with hardner kind of flat where i ground back. Once that is dry, then put a layer of marine tex to seal it or is just the resin fine? I am not sure about the resin part, if i use straight resin or if i have to mix fibers with it. I don't think i can use any cloth as the area is quite small. How long does it take for the resin to harden. I got a cost of $200 for an autobody shop to do it using just resin i think and not any painting. I thought though if just resin, you had to use a layer of gelcoat though or is resin itself fine?

Don't be so afraid of trying to repair the hole. It's only a small hole that you could probably throw a piece of flex seal tape over it if your under way.
It's not difficult at all and I think once you see how easy it is you'll be able to sleep at night.
Go to your local auto supply store, Auto Zone etc and pick up a qt can of "body filler". It comes with a small tube of cream hardner. Clean up the hole like the others described, scoop up a golf ball size of the filler out of the can, squeeze out about 3/4" of hardner on top of that ball, mix it together and squish it into the hole, take the paddle that comes with the can of filler and spread it out evenly. It will set up in about 1/2 hour. take some sand paper and smooth the area down. After you do that you'll feel more comfortable using the product and be able to fix up some imperfections that are in your first attempt. Here are some pictures of holes I filled last week. These were holes from buttons and switches and gauges on an old dashboard. I grinded around the hole, put masking tape behind the large holes and laid in the filler.

The little smudeges of red is body filler "glazing putty" . comes in a tube that you can use your finger to fill in pit holes. no mixing needed.

Watch some of the boatworkstoday video. it will make more sense. it isn't difficult to fix but it is hard work to make it look really good. the holes you have on the bottom don't need to be pretty.

Tomahawk, can you pm me about your boat.

Made the repair yesterday with white marine tex. When i cut and ground away the gel, i could't really see any damaged fiberglass. It it was, it was very tiny. Might sand it some to smooth the corners and maybe a little paint or i might just let it as is. I got the 2oz kit which i had to mix the whole thing so i touched up some other areas. Too bad i had to use all of it at once but figuring out the 5:1 ratio would have been tough and messy. Thanks for the info.

Glad everything worked out ok for you, now you can sleep at night.