Cheers BWD, I'll get busy with the planer and sander and reduce the core to 9/10mm thinning to 3mm at the tips, set the rocker table to 80mm and see what happens

Andrew, if you want a better core material there is a supplier of Airex in the UK that I have purchased from before, the C70/75 is a good strength and density for kite cores and comes in 12mm thick sheets. I think the only sell full sheets which you will get 3 boards out of. Last time I got some it ...

Well that makes things more confusing!?! What if I induce rocker by weighting the board on the rocker table for a few weeks to create all nearly all of the rocker I desire, then say increase the rocker the final 25% or so under vacuum to set the final shape give or take. This should reduce the sprin...

Lots of good advice, thank you all very much.
I will ponder it some more whilst making my rocker table and sorting out a pump and let you know the results

Cheers

Thanks for the info. Unfortunately it has no natural rocker to start with so it will all have to happen under the bag. I didn't realise springback would be so high - from reading other posts I thought it would lose around 25% not 50% plus? With the glass would 0/90 degrees be the best option or woul...

Ok, so I am about ready to start laying up my first cedar strip board, but I am a little lost as to how much glass to go for.
It is a 12mm core thinning to 4mm at the tips and will be vacuumed on a rocker table
Any suggestions?

Thanks in advance