The core will be 8mm thick so it meant creating 2 decks which means that there is the extra step gluing (and waiting) which I've wanted to avoid. Only remedy would be to use thicker core material and work out some way of routing the top deck contours.
I've haven't glued all the planks together to form the core, just built up the two decks so there are now 4 pieces. Assembling the pieces at the time of the lay up seems to work well to reduce spring back of concave and so I'm going to stick to that process here.
|The cut decks prior to gluing together|
|Glued and under the vac bag.|
|The target board design from BoardOff|