21.2#/cu.ft. white cedar (1/4" thick) equals 28.26 lb. and cost is $512.
1/4" (8mm)white ceder with 2 oz glass on each side and some reinforcement on the inside would make a very strong hull.
8mm of white ceder is roughly/sorta/depending the equivalent of 2mm bidirectional carbon
I would probably use 3mm or 2mm as a core
