On Sat, 1 Jan 2011 18:40:06 +0000 (UTC), James Waldby wrote:

If the resulting pieces are going to be interior walls of bat
houses, it seems like you would want to simulate something like
tree bark or rough rock surfaces. Have you tried a coarse wire
brush or a flail on the plywood surface?

Have seen one design where the landing zone (typically the very back baffle
which hangs down 6" below all the other baffles) was covered with a slab of
real bark. Very attractive to us humans though I doubt the bats care. Want to
experiment with a wire brush but I suspect that any plywood soft enough to
raise a gripable grain is going to be too soft over all to work. Or in the case
of quarter sawn boards be readily available already rough sawn as you suggest
below.

The surfaces of rough cut slabs probably would be ok without
further processing, if you have access to a local sawmill.

Will check with our pallet supplier at work and see if he will share his source
of rough sawn lumber.
--
William