>>Finish on fiberglass is never perfect. <<

With composite finishing, learn from the boat builders and the Corvette guys. Lots of time has been spent by both learning to properly finish fiberglass. It can look better than any other construction material if you learn how. Lots of info online too.

Btw, auto shop supply houses, most decent sized cities have them and online too, are a great place to purchase finishing supplies inexpensively.

Bill H.