Why no plywood monocoque homebuilts?

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote

The hard part would be to come up with a reasonable replacement for the spars
in the wings. To avoid the big expensive spruce planks, one might have to
consider an engineered product like Laminated Veneer Lumber (LVL)...

Have you ever used those? They are HEAVY, with a capital "H".

More fitting would be something like an engineered product such as "silent
floor" joists, which is best described as a wood "I" beam. A cheaper wood, like
fur could be used, because the wider flange top and bottom of the "I" is the
only part that is real wood, and there is not that much volume of wood to incur
very much weight penalty.

Holes can be put in the plywood web to help lighten it, with very minimal
strength loss.

Of course, this is a practice very similar to what is currently being used in
some homebuilt designs, today. g

A box spar is one of the best uses of strength to weight for spars, not using a
solid plank. The amount of real wood, top to bottom and spanwise varies, so
there is no extra wood where it is not needed, thus giving maximum strength to
weight. Also, you do not have to use expensive Sitka Spruce, and if you do, you
can cut up smaller (cheaper-no waste) pieces, and splice them, and laminate
them, to get all of the grain going in the right direction.

This all gets a bit labor intensive, but semi-skilled labor can be taught to
make spars, with enough repetition for mass production to be cost effective.

I like the idea of wood mass produced airplanes, but I fear there are too many
advantages for other materials, and pre conceived notions against wood airplanes
to make them fly. (pun intended) g
--
Jim in NC