Gel Coat repairs

Hi everyone, IM brand new here ( and to fixing boats) but this looks like the place to come. I have a 1989 21 ft aquasport cuddy cabin walk around. I bought it 2 years ago and have only used it 6 times so far. Im getting cracks in my gel coat. After looking in the videos it seems there are 2 type gel coat repair types, polyester and epoxy. Which is the superior of these two? Also I keep reading that cracks in the gel coat on the transom can be transom rot. I have crack on each side of my transom in the gel coat. It is right in the corners where the outboard cutaway hits the main part of the transom. they are just hairlines and go only across the top 2" of the inside corners. I have a 2 stroke 225 hp evenrude outboard and have gone as fast as 50+ MPH at about 4500 rpm.

This spring when I came out to check out the boat I did find a soft spot on the deck. ITs about 8" in diameter. It is adjacent to a waterproof access door. IT seems like water ran under the access door edge and rotted out the wood. THe good part is that it is in the middle of a 6' X 4' screwed in panel that comprises most of the floor. WOuld it be better to remove the entiire panel and make a new one, or try to repair the soft spot in the old one?

One more question before I go, should I pull all the screws on the boat and reseal them with some kind of sealant to keep water from entering the wood areas? If so, what kind?

Thanks for any help that you all can supply.

Re: Gel Coat repairs

Welcome to iboats!

Gel coat repairs are only done with polyester based gel coat. Epoxy is not a gel coat because it breaks down in uv light.

The cracks around the transom might just be fatigue, or it could be from rot causing structural weakness allowing the transom to flex and cracks to form in the gel coat. Inspect the transom for rot by drilling holes and inspect the wood shavings. Best to drill from the inside, but you can drill from the outside too. Depending on what you find, fill holes with epoxy like marine tex or replace the transom.

Regarding the soft spot, I think it would be a good idea to remove that large access plate and inspect the stringers below for rot too.

Seal screws with 3m 4200.

Can you post some photos of the problem areas? Photos help a lot.