Hi Warren,
thanks very much for your reply, it's good to know that I can go ahead and place the boards in the shallow bath of resin, then just lightly clamp down to keep things in place (rather than fully clamping to straighten).
To avoid any air bubbles would you say it's recommended to coat the underside of the boards in resin first, letting it fully cure, lightly sand, before I run the shallow bath of resin and place my boards in and lightly clamp?
Also one other question if you don't mind - instead of using a large sheet of polypropylene for the base/sides, would wrapping baking paper around mdf work as a budget option?!
Thanks,
Sam.