Spider line cracks in Gel Coat Concerns?

[tank1949]

I just bought a 30 year old SR Amberjack that is in remarkable shape. I had outside and interior surveyed for structural integrity, and I examined boat?s hull for noticeable issues before buying. I knew it had some keel abrasions but I figured that it would be an easy repair. It was. However, closer examination revealed some hairline gel-coat cracks, almost spider web thickness. These are very difficult to see because they are so fine. I don?t know whether I should invest the time trying to repair them since all boats will develop them. They are spotty. I have three of them between keel and chine. They are about 30-45? long.
All hulls flex but Gel coat doesn?t flex well. Should I repair cracks and what are best tools/materials, process? Grinding down gel coat and putting new back and then sanding seems futile. I could squeeze epoxy into crack as best I could and then re gel coat?
My ?gut? feeling is to leave them alone.
Any suggestions?

 

[DeepBlue2010]

You can not fill with epoxy and then re-gel. Gelcoat is polyester based, it can't be applied over epoxy.

Post some picture to show the location of these cracks. The most important thing is to figure out what caused them to begin with. Sometimes, it is just the nature of the beast as you mentioned. Boats flex and hit the dock and submerged objects, etc. But it also could be an indicator of some structural element that was compromised from inside the boat where these cracks show on the outside.

It could be the time to go through the boat with a fine tooth comb to make sure stringers and bulkheads are sound. Core samples is just about the only way to answer this question. Visual inspection is not enough. If everything checks out, I would personally just leave it alone, it is cosmetic and I am sure the fish would not mind.

 

[SeaDooSam]

I would leave them alone as long as they don't worsen and get bigger. Very thin lines shouldn't be a problem. The problem starts when there is a chip and there is gel coat missing. Then, the force of water will start chipping more at the gel coat

 

[ondarvr]

The problem starts when there is a chip and there is gel coat missing. Then, the force of water will start chipping more at the gel coat

I've never seen this happen, unless you were going far faster than any sport boat would go, gel coat wouldn't peel off unless there were other issues.

 

[SeaDooSam]

it happened on our jetboat. A small chip had gotten a bit bigger. Luckily we caught it in time. may be other problems with the gel coat though I don't know!

 

[ondarvr]

If there was an air bubble under the gel coat it could continue to chip away until the entire bubble was exposed, but the laminate and gel coat basically become one as they cure, so separating them is difficult.

 

[Woodonglass]

Pics will help. Based on your description, I agree with SDS. No worries.