Recoring Dech Hatches, strong enough?

[Boatboy6]

I ordered some dyvinicell h80 1/2" to recore some deck hatches (forward fish box and aft tank cover) on the SeaCraft. The largest hatch is 36x36. I plan on laying down a layer of matt or 2, bedding the coring in mertons hull and deck putty, and then lay down a layer of 1708 with vynlesther resin. Should this be strong enough? I don't want to have to worry about it and looking at the 1/2" I'm beginning to think I should have got 3/4" instead.