Which option is stronger on the deck for 100 Kg surfer?
stronger as in: less dents
stronger as in: less likely to break
A. 2 mm balsa under 1mm cork
B. 2 mm balsa over 1mm cork
both with glassfibre 0/90 either side
Cheers
Just a guess. The balsa on top.
My reasoning is to look at the skin like a beam. The top of a beam acts in compression, while the bottom acts in tension.
In both cases, the bottom of the beam is fiberglass. The taller the beam, the stronger it is. So put your strongest compression material farthest from the tension (bottom) side of the beam.
This theory works up to the point of catastrophic failure, where you stress the compression balsa so much, that it cracks. It would then instantly go to zero strength.
Wood has the same inherent problem as glass. It gives to a point, then shatters.
Drop a glass pickle jar on the floor. Drop a plastic soda bottle on the floor. Which one shatters, and which one bounces back? Also, which one is lighter?
Take the fiberglass out of the build, and use something less prone to shattering on impact.