On Apr 18, 10:15 am, Bart wrote:

...Second, when you guys build (built?) monocoque small aircraft
structures of the stringer/skin/bulkhead type, what thicknesses of
plywood do you typically use?

Well, "monocoque ... structures of the stringer/skin/bulkhead type" is
kind of an oxymoron. Technically speaking, monocoque structures are
stressed-skin shells that, because of their stiffness and shape,
require no internal structure. However, such structures are somewhat
problematic when it comes to buckling and crippling, so the more
common implementation is "semi-monocoque" in which the skin still does
the heavy lifting, but is stiffened with internal structure that helps
it hold its shape. I think that's the kind of thing you're talking
about.

Anyhow, semantics and minutiae aside, have a look at the Web site for
the Sequoia Falco, a homebuilt kit based on a certificated Italian
speedster from the mid-1950s:

http://www.seqair.com

The builder's photos are very interesting and informative. Also, the
skunkworks articles have a lot of good info:

http://www.seqair.com/skunkworks/skunkworks.html

Construction Note 61008-1 shows that most of the fuselage skins are
2mm or 2.5mm, and the cockpit interior skins are 1mm - waaaay thinner
than I'd like between me and other motor vehicles.

As another reference point, the Bowers Fly Baby uses 1/8" (about
3.2mm) plywood for the sides of it's fuselage.

Thanks, and good luck

Bob K.
http://www.hpaircraft.com/hp-24