Gel Coat Repair on corner of gas tank lid

[SmokyMtnGrady]

Hey Y'all:
Hope your covid-cation is going swimmingly. We are building out a new espresso bar in our Waynesville store. I am thankful in one way for this Covid crap and that is this spring I am doing a lot of boat repair myself. This past summer I noticed the smell of fuel when we filled up the boat. I peaked under the gunwales and saw fuel leaking out of the fill hose. My tilt helm is royally messed up.

So, I ordered parts to fix the fuel fill and vent hose, seastar tilt helm, and a new Garmin GPS. Last weekend I started the prep. I pulled the tank lid and pulled out my hoses. Today I installed the hoses with new stainless clamps. I scraped the OEM caulk off of the lid and noticed the caulk was concealing what I believe to be a factory installation error as there was a big chip out of gelcoat out of the corner of the tank lid.

Question, what's a good way to repair this? My thinking is to take a piece of cardboard and wrap it around the corner as a form and then pour gelcoat over the damaged area and level it out. There is exposed glass under the chip and it's about maybe 1 square inch in area . It formed in my observation as a spider crack or something when they screwed the lid down. As it radiates off that screw hole in the top corner of the lid. I bought the boat new in 2009 and never noticed this and this is the first time ever the lid was removed. I didn't chip it .

Anyway , any knowledge from you guys would great here. Thank you in advance.

 

[mleads310]

Spectrum color match gelcoat repair kit. It's a paste with hardener. Like 30 bucks I think.

 

[DennisG01]

A picture would help tremendously, but as I read the post it sounds like the area is covered up by the sealant that goes around the perimeter. It also sounds not like an installation error, but a somewhat common error in glass layup called an air void. Basically, an air pocket. Since you're not going to see it again once you put the sealant back down... and it hasn't gotten worse in 11 years, you could realistically just let it be. To fix it properly, though, you need to grind out the area till you eliminate the air void, fill with epoxy/possibly thickened epoxy, then gelcoat over top. You may get away with just epoxy, after grinding, if the repair will not be seen. You also might be able to just fill the pocket with some epoxy and not worry about the grinding.

 

[SmokyMtnGrady]

A picture would help tremendously, but as I read the post it sounds like the area is covered up by the sealant that goes around the perimeter. It also sounds not like an installation error, but a somewhat common error in glass layup called an air void. Basically, an air pocket. Since you're not going to see it again once you put the sealant back down... and it hasn't gotten worse in 11 years, you could realistically just let it be. To fix it properly, though, you need to grind out the area till you eliminate the air void, fill with epoxy/possibly thickened epoxy, then gelcoat over top. You may get away with just epoxy, after grinding, if the repair will not be seen. You also might be able to just fill the pocket with some epoxy and not worry about the grinding.

Perhaps thats what it is. I think the epoxy route is the way to go. The exposed glass looks like muscle fibers. I don't know if I will have my boat in 5 years or 11 more ,either way I think it needs to sealed up to prevent any water intrusion beyond what might have already occurred. The deck panel is solid , no soft spots and the corner is solid too. Thanks for the feedback.

 

[SmokyMtnGrady]

Spectrum color match gelcoat repair kit. It's a paste with hardener. Like 30 bucks I think.

I have done this before. It's a good idea. I need to order an OEM part so my thinking was to have the dealer add a bottle of Grady gelcoat to the order and ship it my way.

 

[Fishtales]

You can also fill with marine tex and cover over with gelcoat.

 

[DennisG01]

The exposed glass looks like muscle fibers.

There 'ya go - that's a perfect description. Yup, air void. It's most common in outside corners/edges given how the panel was made. When it was made, this was actually an inside corner/edge. The first step to making the hatch is to apply the gelcoat to the inside of the mold - that usually goes just fine. The next step is to lay in the glass into the mold and squish-in the resin. That's where the issue happens - everything isn't always "squished-in" to inside corners as well as they should be and it leaves an air pocket. When it comes out of the mold, it appears fine - and then at some point down the road this weak spot gives way. There's probably others on your boat, too!

The goal of the fix (if you're going to go at it full bore) is to keep grinding till you get to solid glass/resin - you'll know when you get there.

Otherwise, remove the hatch and prop it up so the cavity is facing up. Build a dam around the area if needed to capture the epoxy. Heat the area up. Then dribble epoxy resin into the cavity - slowly to avoid air bubbles! If you have a syringe, that'll work, too. Or make a "cake decorators" bag out of a plastic baggie. Once it's dry, give it a quick grid/sand to get the general shape back so the hatch fits back in it's hole well enough. The epoxy doesn't need to be top coated in any way. While not "as good" as doing the full grind method, this should be absolutely fine for this repair and it saves you from more work and the subsequent gel repair.

There's more than one way to skin the cat here - that's just a couple of the ways I would attack it.

 

[leeccoll]

After you seal it to your comfort level, this gelcoat paste as mleads 310 said is easy to use and does not sag while you apply it. Think peanut butter consistency.

Good luck!

Lee

 

[DennisG01]

After you seal it to your comfort level, this gelcoat paste as mleads 310 said is easy to use and does not sag while you apply it. Think peanut butter consistency.

Good luck!

Lee

View attachment 12622View attachment 12623

"If" the repair is visible... an even easier solution is to just use some white paint

 

[leeccoll]

"If" the repair is visible... an even easier solution is to just use some white paint

Now Dennis, where is the fun in that?? Can't make life too easy these days

I now must disclose I used some enamel paint yesterday on a couple gelcoat minor cracks and it did a good job of blending. Dabbed it on with a fine paintbrush, then wiped off surface with a rag.

 

[SmokyMtnGrady]

You see maybe 3/4 inch topside and it rolls down the edge. I will take a picture tomorrow. It's raining and grey. My son and I installed a new hydraulic helm today and bled the lines. I need to go fix supper . I have the GPS to do and fix the tank lid . Wait, I am replacing my scupper hoses too. Lol.


Any way I do want it to look nice. The void happened on the top left corner so it's just below the companion seat in front of the cabin door. I think gel coat would be good.

So, one other question. I don't own a Dremel tool, could I use a grindstone on a cordless drill?

 

[DennisG01]

I now must disclose I used some enamel paint yesterday on a couple gelcoat minor cracks and it did a good job of blending. Dabbed it on with a fine paintbrush, then wiped off surface with a rag.

Ain't nothing wrong with that!

On my last boat, a 28' Sea Ray cruiser, it had bottom paint (I was the second owner) but I trailered it. So I didn't really need the bottom paint. I just let it keep wearing off, but I wanted it to look nice around the water line. A couple times, I just used some cheap, black spray paint to touch it up! Was it the "right" way to do it? For my situation it was!

 

[DennisG01]

So, one other question. I don't own a Dremel tool, could I use a grindstone on a cordless drill?

If it's small enough and does the job, I can guarantee you that the air void won't care!

Beware, though... sometimes the air voids are 3x bigger than what you think. You need to grind back to where there is solid adhesion between the gel and the glass. And leave a shallow, bevelled edge around the perimeter for a stronger repair. Depending on how big the exposed void is, you may want to first coat the inside of the void with epoxy, then thicken it up and maybe even add in some chopped up fiberglass (think: re-bar in concrete).