Hi Gene,

I have a different outlook, a different understanding than many modelers.

Any plywood made of birch is not really a light weight compared to plywood made of ligther woods.

I have made tail feathers of what I refer to as light ply by laminating three 1/16" thick medium hard balsa.
Since balsa breaks or cracks easily along its grain, The middle layer was glued 90 degrees with the two outer layers that ended up span wise on the horizontal (stab and elev) and up and down for the verticals (fin and rudder). The middle layer considerably preventing split of the surfaces.

A similar action is provided when those tail items are made with ribs an sheeted.

Best 2 U

Zor