wood coring question

[wellcraftv20step]

The starboard I know from experience is a no no over the fuel hatch or on the floor anywhere, my v came with a starboard as a replacement for the fuel tank cover .it flexed like crazy even with layers of angle iron on the underside.and I could not find any thing to bond to it as skunk said.i actually started a thread some years ago showing how I built a mold and fabricated a new hatch.i just can't remember what I used for coring , I have my epoxies and cloth material coming from us composites in Florida so I only have a couple of days to get the coring material ...I was thinking dry ply because I've used it quite a bit and generally it's a very good quality and very stable