On Fri, 15 Jul 2005 05:30:38 GMT, blueman wrote:

if you determine that a preloaded shelf laminated from 2 layers of 1/2"
BB is insufficient, a torsion box shelf or center pins may be in order.
if you go torsion box, consider 1/2" for the top layer, a 3/4" web and
1/4" for the bottom.

Assuming that you are talking about 3 sheets of plywood sandwiched as
above, does a torsion box like that really work in the sense of being
stronger than just two 3/4" sandwiched together (both have the same
total width of 1.5")


the solid shelf will be slightly stronger. the torsion box shelf I was
picturing involves dimensional 1x as the interior webbing. the
advantages of this approach are weight, cost, ease of assembling a
prestressed panel.