It depends... gelcoat cracks come in several forms...
If they're random crazing or "spiderwebbing", then, it is probably a cosmetic problem only.
If the cracks are radiating from a central point, it is usually the result of an impact of some sort.
If the cracks are parallel, it is usually the result of the laminate flexing and the fiberglass may need to be reinforced to prevent them from re-occurring.
Gelcoat cracks are fairly common, especially if the gelcoat layup is a bit thicker, since gelcoat is more brittle than the underlying fiberglass laminate.
Generally, gelcoat cracks need to be opened up a bit and then filled with either thickened epoxy or gelcoat, depending on how deep they are. BTW, you can gelcoat over epoxy, provided you prep the epoxy surface properly.
Have a 86 O'Day 35 which is now showing hairline cracks at corners and stress areas. Fiberglass guys say it is the gelcoat drying out and its only cosmetic & ignore it. I would like to get these cracks repaired (smooth & antiskid). Is there a easy fix? Thanks for all info.
