Could you please share your opinion and maybe some experience on making stiff hatch lid for board compartment. On my build now I’m, using 15mm Plywood. But plywood will suck water and with time it will be destroyed. So now I’m looking for other options with the same 15mm thickness.
CFK sandwich board, strong and light, it can be made thinner i.e. with 8mm core. Foam core with 2x 300g CFK on each side should be enough. Rohacell would be a good core material but not cheap. AirexC70.75 works as well.
I am currently making the top of the MALA box in Airex C70 in 15 mm thickness, the result is very rigid and very light. This is a lot of work:
2 layers of fiberglass on the inside and outside edges then 1 layer of fiberglass on the top and bottom (also covering the inside and outside edges) then 1 layer of carbon fiber on the bottom (on the MALA side) and 2 layers of carbon fiber on the top. And finally glazing before 2K varnish.