If the epoxy is not soft or in liquid form, try coating over it with some Duragloss LS Supreme. I've applied this finish over flexcoat with good results. In my opinion, flex coat is garbage. Syringes are pretty fail safe, but they can introduce air. Agressive mixing will also introduce air, which is hard to get out of flex coat. The LS Supreme is thin enough that you can practically whip it. Spread it out on a piece of tin foil so that the air bubbles will pop and apply with a brush.

This should have been posted below in reference to the tacky flex coat finish problem