Delamintaion in Hull

[Hankthelank]

Hi all,

I've noticed that the gelcoat has lost adhesion to the fiberglass on a section on the port side of my hull . I assume it's either from age, contact with the finger pier (fatigue) or a combination. Either way I was wondering the best way to repair. The area is significantly large , 5'x3', located at the widest part of the boat. I was thinking of drilling many small holes and injection epoxy. Cutting out the piece of gelcoat, applying epoxy and then replacing would probably be better but keeping constant pressure while the expoy kicks might be difficult. Anybody do a repair like this? insight?

cheers,
hank

[Sailmonkey]

Gelcoat is just a paint like coating, if it's come off of an area that large you'd be best to re-gelcoat, or paint with some fairing.

[tager]

YIKES!

If the problem is really just the gelcoat, and not structural, it should be pretty easy to strip it all off and apply new gel coat, just make sure the glass is super clean, and use the thick gel coat. Then sand, sand, sand, and buff, buff, buff. When you are done with that, buff some more.

Messing around with epoxy is just going to be a waste of time.

[Sailmonkey]

forgot to mention......if you spray or roll on gelcoat, cover it with mold release so it'll cure fully

[Hankthelank]

Originally Posted by Sailmonkey

forgot to mention......if you spray or roll on gelcoat, cover it with mold release so it'll cure fully

Thanks folks. Have yet to do an gel coat work. Time to learn.

hank

[S/V Illusion]

Ive seen this happen on certain boats which have an epoxy hull to which the builder tried to adhere gelcoat - it doesn't last.
You can try all kinds of bandaid type fixes but the only way to do it permanently is to do it properly and that means peeling off the gel, fair, sand, fair again, sand and paint her.
You will find when peeling off the gel that it comes off in sheets so the first part is easy.

[speciald@ocens.]

Is it a cored hull? Does it sound hollow when you tap on it? It may be more serious than you think. It could be a delamination or crushed core - much more structural and difficult to repair. I doubt that it would be just the gel coat separating without any surface cracking. If there is not core damage; cuttting out all of the damaged are followed by fairing with thickened epoxy - West Sysytem, then spraying with gelcoat, cover area with plastic wrap until it kicks, then sand with progressively finer sand paperand compound. Matching the color, even white, is difficult.

[forsailbyowner]

Gelcoat for surface application is available with a wax additive that will cure. FGCI.com

[Hankthelank]

Originally Posted by speciald@ocens.

Is it a cored hull? Does it sound hollow when you tap on it? It may be more serious than you think. It could be a delamination or crushed core - much more structural and difficult to repair. I doubt that it would be just the gel coat separating without any surface cracking. If there is not core damage; cuttting out all of the damaged are followed by fairing with thickened epoxy - West Sysytem, then spraying with gelcoat, cover area with plastic wrap until it kicks, then sand with progressively finer sand paperand compound. Matching the color, even white, is difficult.

No it's solid fiberglass. I have a bad feeling the fiberglass might be damaged. Thinking back it might have occured during hurricane Ike. I was on a fixed pier, and the water level rose 10 feet. My neighbours boat broke free and hit mine. Appeared as if it only bent a stanchion and scratched up the side of the hull. I didn't notice the issue with the gel coat. I guess once I get the boat out of the water, it will be exploratory surgery.

[Geminidawn]

IMHO it's not just the gel coat, unless there was some contaminant when the boat was being built or the boat was repaired poorly at a later date it is very rare for gelcoat alone to seperate from the laminate, the chances are the gel coat has taken a couple of layres of laminate with it.
Here is the kicker, if that is the case then you will have to repair it with epoxy as polyester resin has no secondry adhesive properties what so ever. Your repair area will be the damage + 12 times the thickness of the hull to spread the load. You may be fortunate where only the top couple of layres delaminated leaving you a base structure to work from.

Here's one I did earlier, where the edges of the repair were tapered off x 12 and then the area mapped and rebuilt, the total number of laminates depends on the thickness of the hull you are trying to rebuild and the weight of the cloth you are going to use.
Flatten it all back and leave it for a good ten days for all the ammonia to escape before recoating it with gelcoat.