Damaged hull gel coat

[Wallman67]

http://i936.photobucket.com/albums/ad202/Wallman1967/1976 Glastron T166 Restore/BoatPictures009.jpg

Here's sample of a spot on hull. Now that I have flipped the boat I can better get at it. What is the best repair ? I'm re-painting the hull. Should I sand out all the damage and fill area with thickend epoxy and glass bubbles ?

 

[NetMatrix]

Re: Damaged hull gel coat

The damaged area will have to be sanded/grinded out completely. Then go back over the damaged area by re glassing it. Get some fiberglass cloth and the resin. On the inside of the hull put a really thin coat of resin then apply the cloth over that make sure it overlaps the damaged area at least 3 inches. Then glass it from the inside. Once the inside is glassed flip it back over and glass the outside of the hull.

I help a friend of mine repair some damage on his hull, and this is what he did to it. That was 3 or 4 years ago, and it is still holding really strong. Now you do want to make sure on the inside of the hull apply a little extra resin to make the damaged area a little stronger. It's just like when you break a bone or something in your body that done will grow and calcuis over the broken area to add strength to it. Good luck.

 

[Wallman67]

Re: Damaged hull gel coat

Ok , do you mean grind/sand the damaged gel coat off down to the fiberglass or also grind/sand to remove the fiberglass as well creating a hole. Then patching it as a hole......OR
Can I grind/sand the damaged gel coat off down to the fiberglass, re-enforce the damaged area on the inside by fiberglassing an overlapping patch, then re-glassing the outside. I guess this way I'm not creating a hole.

 

[saildan]

Re: Damaged hull gel coat

Ok , do you mean grind/sand the damaged gel coat off down to the fiberglass or also grind/sand to remove the fiberglass as well creating a hole. Then patching it as a hole......OR
Can I grind/sand the damaged gel coat off down to the fiberglass, re-enforce the damaged area on the inside by fiberglassing an overlapping patch, then re-glassing the outside. I guess this way I'm not creating a hole.

All of what you say could be necessary. I all depends on if the damage is just superficial gelcoat blistering, delamination of the fiberglass below the gelcoat, or impact damage to the fiberglass.

Gelcoat blistering could just be sanded back to the structural hull then faired out in prep for painting. Damage beyond that gets treated as a hole. Regardless if the fiberglass has been moisture delaminated, cracked, or broken through, it's lost it's structural integrity. The busted stuff needs to be removed and the area reinforced inside and the gap bridged.

If you leave delaminated or broken pieces in place and layer behind them, then sand and fair the surface over them, you'll have a soft spot. Paint (or new gelcoat) isn't 100% moisture-proof and it will be forever blistering and peeling in that area because the underlying breakage will allow moisture vapor to permiate and find a place to collect.

 

[NetMatrix]

Re: Damaged hull gel coat

Ok , do you mean grind/sand the damaged gel coat off down to the fiberglass or also grind/sand to remove the fiberglass as well creating a hole. Then patching it as a hole......OR
Can I grind/sand the damaged gel coat off down to the fiberglass, re-enforce the damaged area on the inside by fiberglassing an overlapping patch, then re-glassing the outside. I guess this way I'm not creating a hole.

Grind out the damaged area if any of the hull is cracked or what not. Then use a sander to sand it down to the fiberglass. Clean it up with whatever chemicals are used to clean the dust up. Then apply the resin/cloth then sand to make smooth. If you see any tiny holes in the repair area apply another thin coat of resin then sand, and prime then finally paint.

On the first link in my signature is my Ebbtide that I'm rebuilding. There is 2 or 3 pictures of where I had to do repair to the hull. The inside of the hull you will see the dark resin that was laid on extremely think, and on the outside of the hull you'll see the the exterior repair portion. You just have to be extremely careful when dealing with fiberglass, and wear the proper attire.

 

[Wallman67]

Re: Damaged hull gel coat

Understand...best if I treat it as a hole. I'll grind/sand off the gel coat and continue thru the fiberglass to create a hole. Doing the repair then as a hole. I'm wondering if I should do this to all the suspect area's that are cracked or chipped ? There's a couple of chips that I can see exposed fiberglass, I should treat them this way also.

Now that I have the boat flipped I can go over all these area's and look at them more closely.

I just just read NetMatrix's reply.....the method he mentions might work for the repair. I'll grind/sand off the gel coat and look at the fiberglass damage then try to decide how bad it is. If it's bad I'll grind thru and do it as a hole, if it seems ok I'll do it like NetMatrix explained. I'll post pics.