Life of Gel-Coat
Colin,Fiberglass (and other composites) is what I do for a living, or at least to earn money to spend on my boat. If it is a good quality gelcoat, the expected shelf life would be about 6-8 months (obviously un-catalyzed) It can be used well after that if the storage conditions are good. It just tends to get a lot gummier & hard to work. Thinning it w/ Acetone is what a lot of people do, but not highly recommended. You oughta try & use it up before that time or you'll end up w/ a large chunk of worthless color in your can.Regards, Richard C