Just finishing making a 105(ish) wave board, 28kg eps, double 6 bottom, carbon rails, 6/veneer/6 deck, and obviously getting heavier than production boards, but ok. As a finishing coat, i was going to epoxy/sugar the deck, and q-cell/sand the bottom. Question is, will the bottom be ok without another coat on the filler, or should i 'hotcoat'? I know there have been lots of build threads and this is likely covered, but they seem to have disappeared. I don't really want to spend too much (2 pack etc) on an experiment, when the board has cost me less than ?300 so far. Thanks for any input.

Don't need 2 pack on an expoxy board.
If the veneer deck looks good then no paint required.
For the bottom use automotive primer and spot fill pinholes then wet sand and second coat with 400 grit wet sand finish.

Post a few photos, always interested to see

+1 ^
Auto motive stuff won't wear as well as two pack, but if you look after it will be fine

Depends on how much you are trying to hide. I have started hotcoating with resin. For my last two boards I have used UV catalysed Silmar polyester resin, but my boards are full sandwich and / or have PU blanks. I like the gloss finish you can achieve and it is harder wearing than 2 pack pu clear coat.

You need a good key 40 - 60 grit and it takes several goes to get a flat clean surface. I think if you are happy with a matt finish then epoxy could also be used.

If you have access to a spray gun with a big nozzle, you could use a high build polyester filler paint coat to fill and hide pinholes and glassing / weave. Then spray a white primer and the uv Clear coat.

All depends on what tools you have access to. Personally, I have tried loads of different ways, but classic surfboard hot and gloss coating is by far the easiest for a backyard builder in my opinion.

As you have just done glass over styrofoam it will need a perfect fill as just one pinhole will suck water. I'd do hot coat and sand then primer and spot putty pinholes, sand and primer again looking for pinholes

Thanks, all. not worried too much about appearance, (quite like the grungy look) so will just try and find all pinholes, and seal , but did each lamination separately, so hopefully pretty well sealed. Will post pics soon.