I built a 9 foot surfboard from a Grain surfboard kit out of red and white cedars and used MAS medium epoxy for fiberglassing and its finish!
I'm a beginner who made plenty of mistakes and the epoxy's longer setting time allowed for me to go back and fix those tiny blemishes or remove the pesky fruit flies stuck in it!
The end result was such a smooth and clear finish that I didn't need to do much sanding at all!
I'm working with MAS epoxies on all my future projects!