Is there a product available that comes in a spray can to gloss a new board after the final wet and dry sand? I only plan to shape a board here and there and dont want to fork out for a compressor. Cheers.

I used a clear acrylic lacquer that comes in a spray can, brought it from bunnings cant remember the name. I used this over a vac bagged epoxy board I built. Finish came out really good. Should work over Poly but I am not 100% sure. Might pay to do a test.

Other option is to take it into your local shop to do the finish coat on, shouldn't cost too much.

cheers

Anchor clear spray paint, used it on a board that I re-glassed to give a nice gloss finish.
Anchor is the best I believe for what you want to achieve. Try it on the car as well if you have lost some duco, gives a bit of a shine.