Help on repairing gelcoat. Bumped the dock.

jpeac2 · #1 (**permalink**) 06-25-2007

All -

Would appreciate some help as I have done some damage to the boat. Two weekends ago I was pulling out of the slip and due to some currents the boat was forced into a 2x4 hanging off the end of the pier.

Upon inspection there was some damage done right below the porthole. There was one small hole at which the size appeared to be just larger than a pen's diameter. Additionally there were two hairline cracks that do not directly intersect the hole. If you look into the hole you can see down a little bit and it appears you are looking at the fiberglass underlay (not sure if that is in fact what it is).

My question is in regards to repairing. First off, did I just damage the gelcoat? Or is it possible it went further? I spoke with a gentleman at a local marine store and he suggested using a repair kit and mixing the compound and just aplying to the hole. It sounds too simple.

What should we be doing to insure that it does not spread and that it is done correctly?

Thanks for any and all help!

mathislaw1 · #2 (**permalink**) 06-25-2007

I slammed into a dock about two months ago with my boat and knocked a piece of gelcoat off about the size of a quarter. I bought an epoxy called marinetek from West Marine and made the repair myself. It wasn't hard to do just follow the instructions on the bottle. Be advised this stuff is extremely hard to sand, but there is nothing on the market stronger.

jpeac2 · #3 (**permalink**) 06-25-2007

Mathislaw1-

When you kocked a chunk off, was there a noticeable hole? I can see into the hole I created. Which makes me wonder. Is that normal?

tagster · #4 (**permalink**) 06-25-2007

jpeac2 - That's not normal. Can you take a picture of the damage? The way you're describing it, seems sort of curious. Also it sounds like more than just gel coat damage. You might have some much more serious glass work to do than just gelcoat repair. Gelcoat is nothing more than a material used to create a high quality finish on fibre-reinforced material such as fiberglass. If you can see through the hole, the damage is actually in the fiberglass itself and not the gelcoat.

It'll be easier for people to give advice if you take a photo.

JeffreySiegel · #5 (**permalink**) 06-25-2007

Don't be afraid to repair gelcoat. It is one of the easiest things to do - although it takes a little practice to get it perfect. It usually costs a fair amount to have other people do it because it's the kind of thing that usually takes 2-4 different small-effort processes. When you pay someone else to do it, they have to keep coming back to your boat. It's the perfect thing to learn how to do as a do-it-yourself'r though.

There is plenty of information on the internet about how to do it. I've been doing it for about 3 years now (a couple of fixes per year) and it comes out great. I prefer the method that uses a Preval sprayer ($2/canister).

Don't fear it and don't be scared off by some people who will make you think it is really hard to do. It's very, very simple. The best part is that mistakes can be sanded out and tried again...

jpeac2 · #6 (**permalink**) 06-25-2007

Quote:

Originally Posted by tagster

jpeac2 - That's not normal. Can you take a picture of the damage? The way you're describing it, seems sort of curious. Also it sounds like more than just gel coat damage. You might have some much more serious glass work to do than just gelcoat repair. Gelcoat is nothing more than a material used to create a high quality finish on fibre-reinforced material such as fiberglass. If you can see through the hole, the damage is actually in the fiberglass itself and not the gelcoat.

It'll be easier for people to give advice if you take a photo.

Here is the odd part and perhaps why the hole is how I described it.

As the hull recedes to the porthole, there is a curve to where it goes from being a vertical surface to where it meets the horizontal surface. That curve that transitions the two is where the hole is. Therefore I am thinking there might be a slight space in between due to the porthole being sunk back ever so slightly.

Does that make sense?

JeffreySiegel · #7 (**permalink**) 06-25-2007

...or possibly the curve was made will filler material to provide a nice smooth edge with gelcoat over it. When you cracked off the gelcoat, some of the fillter was removed too.

If the glass was chipped (unlikely) or cracked (possibly), you have to fix that before worrying about the gelcoat. That is very easy to do too.

hellosailor · #8 (**permalink**) 06-25-2007

jp, right now it sounds like you can put some white gaffer's tape over it (doesn't leave goo luck duct tape) and keep sailing.

For the longer term...the pen-sized hole has to be filled. You can do that from the inside or outside. One idea might be to sail around to some shops that do fiberglass work, during the summer, and ask them about a repair after the season or when they have some slack time (since "I need it now" usually costs more).

Gelcoat and FRP has different elasticities, so the FRP underneath probably bent in and bounced back out, without structural damage, while the gelcoat over it "popped off" and cracked at the stress areas. There's a case to be made for just applying a FRP repair on the inside, over the area of the dent and crack, and if it isn't in an ugly exposed area--just build up a patch and let it be "just in case" the FRP fibers are damaged in there.

Then, scratch out the cracked gelcoat (with a can opener, reamer, or dremel bit) to open up the cracks, round off the ends of them so they don't spread, and use a gelcoat repair kit on the outside, for the cosmetics. Gelcoat repair can be a lot like airbrushing--it takes a good hand and eye to really hide something, you need to feather it out and work using LESS rather than what you think is enough. Remember "less is more" and a truly invisible repair requires a very good touch--or calling in a pro.

If you check out west marine systems (gougeon brothers) online, they have extensive docs about doing all the FRP and gelcoat repairs. They'll also answer all your questions on the phone--you pay for the call, that's all. Needless to say they hope you'll buy their materials, which are top quality.

Or,you can always go to a vinyl shop and have them make up some interesting graphic to apply over it, and hide it.

xort · #9 (**permalink**) 06-25-2007

Sounds to me like a void in the fiberglass behind the gelcoat. The gelcoat was laid tight to the curves of the mold but the fiberglass didn't fill all the way into that same curve. When you punched the gelcoat, you revealed that void. I don't have experience in repairing gelcoat but it would seem to me that you would have to chip away all the gelcoat that doesn't make contact with the fiberglass underneath and then make repairs.

hellosailor · #10 (**permalink**) 06-25-2007

xort-
I'd agree that "the right way" to do it is to grind out the entire area and rebuild it...but that could also get big ugly and expensive, as opposed to just resealing the cracks, and if there's a void back there that's been quiet all this time...so what, it's above the water line and not bothering anyone.

A couple of cracklines...or a dinner plate sized repair? Sometimes we just look away and go sailing.