Reparing Exterior Damage

If you look at these pictures you can see there is some damage where large chunks of gelcoat are gone and been filled. There is also a crack that runs about 12".





Yesterday, I was messing around with this and noticed it seemed hollow underneath. Also some water would ooze out of the crack when pressed on. I pressed kind of hard in one area in front of the area filled and it collapsed. I started messing with it and realized it was relatively hollow underneath, so I picked at it and chipped away gelcoat layers until it seemed solid again. It is almost as if there was a void under the gelcoat. I'll post some pictures of what it looks like now.

I'm trying to decide what my options are at this point. I figured it wouldn't be good for it to continue getting wet under there. I'm not sure I can do a full gelcoat repair right now, but I want to at least "waterproof" it.

Can I fill it with a thickened epoxy for now and tackle the gelcoat part of the repair later?

Is so, is there a particular filler needed or can I use some of my leftover cabosil or glass bubbles?

Will I need to grind away more?

Any help would be appreciated.

Andy,
Use vacuum or a heat lamp to dry it out overnite. Tap it out, the sound will change from solid to delaminated. Cab-o-sil thickened epoxy will work. Without pulling it all apart maybe you can "lift" the gell with a scribe or the tip of a knife and inject some epoxy in the delam.

Here's what it looks like after I chipped away at it. Only the area in the right hand part of the picture has any hollow area left and only towards the bottom. All the rest has solid fiberglass at the edges. Can I just fill this entire void with thickened epoxy, then later sand / grind and then do a gelcoat repair?

Andy,
Getting epoxy into that large void is a good idea however there are some cautions. Don't fill the void completely to the surface of the old gel. You need to leave some room for the gel. Now the problem! on such a large fill, the polyester gel will not stick to the epoxy. You need a "conversion" layer of polyvinyl. It sticks to epoxy and the gel will stick to it. Once filled, you'll need to grind out the fill at the edges so there's a "step" for the gel fill.

Andy, I would think you could tape everything around it to protect the gel from the stuff you put down. I like waterdog's idea of touching it up with some awlgrip to keep it looking decent from 10 ft

I'd also taper sand the edges of the gel so that you will have a smooth transition from the solid gel down to the fiberglass. Jagged edges aren't good as the potential for airpockets are there which will lead to imperfections in the finish coat. You don't want a "jigsaw puzzle" look or "moon craters" when you do the final wet sand. Also, if you taper sand, the new gel will have a nice smooth surface to bond to.


**EDIT** Also be VERY careful if you choose to use a heat lamp and dont get it too close to the good gel. You risk disbonding the good gel coat and your problem just got bigger. TRUST ME on this one. I learned the hard way.

Moorfoot,
Your right about the heat. Make sure you can lay your hand on the warm boat surface, it NEEDS to stay at 150*f or so overnite. Higher temps will dis-bond the ajoining areas. Another reason I like to draw water out with vacuum.

Sounds good guys. Thanks. I'll hit it with a dremel to rough it up, including feathering the edges and smoothing the surrounding gel. I'll fill with the thickened epoxy and smooth out for now, then I'll get back to it later to finish it and get the gel on there.

I think I would agree with the cause. It does look a lot like a void that was always there. Maybe hull flexing caused the gel to crack and chip away at some time, but I have a feeling there has always been a hollow area in that spot.

Andy,
For getting down into spots as well as routing out cracks, I like the 1/8" diameter ball shape because it cuts on the sides as well as the end.

For evening off the gel edges, I'd use a straight spiral cut bit. The larger the diameter you use will give you more control over the cut. It may get tricky because it all a free hand cut. Take your time.

Andy,
You do good work!!

The next step with the gel is the tricky one!! When you get to it, the old edges will need some clean up as mentioned.

How far down the hull side do you think the void go or where you able to grind down to where the void stopped? I'm just curious. Getting the epoxy down into it I'm sure will do the job.

Found a few other cracks when I was working on a few things this weekend...arghhhh. I don't think the other cracks have voids underneath, no hollow sound or feel. One crack is on the port side about midship and it is vertical...about 1" long. I found a couple cracks running horizontal right in the same bend transition area as this one. They are hairline cracks with no delamination. Should I leave them along or do something about them?

Either that or there may have been some stress on those areas due to the rotting issues that were found.

Could this repair suffice for the season or should I get gelcoat on it before this season?

I found a place locally that has gelcoat with MEK in i who is saying it will work for my application? Any input on this? I'd love to support a local business if I can.

It's an 89 Sunsport.

Supra went to all composite during 92 so some 92's are still wood. Definitely all the 93's are all composite, though.