I hope I'm not intruding here, but I'm building a car with a plywood
monocoque chassis bonded to fiberglass body panels. It's not as
bizarre as it may sound: the chassis design is based partly on that of
the Marcos GT, which used exactly that model of construction. The
chassis designer was Frank Costin (the "cos" of Marcos), who had done
a great deal of the design work on the deHavilland Mosquito, the
British plywood monocoque WWII fighter-bomber. As I'm sure you
aircraft folk know, a plywood monocoque has exceptional torsional
rigidity for its weight.

The car I'm building is open, so the rigidity loss inevitable with an
open cockpit will be largely restored by the use of deep, boxed side-
sills, fore- and aft-bulkheads, and a deep, chassis-long central boxed
spine, much like the Lotus Élan.

I'm looking for advice on bonding and bond-strengthening plywood box
structures (Marcos, for example, used spruce reinforcements at all
joints), and what thickness and kind of ply (Marcos used marine).

Any suggestions (besides the obvious!) greatly appreciated...

Bart Brown