I understand slight variances. But that does not explain why the thickness
of the veneers cannot be compensated to end up with a finished product of
stated dimension.

"John" wrote in message
...
I have been in the veneer business for a long time. Remember, we are
dealing
with living material, subject to expansion and contraction with
temperature
and environmental changes. When rotary cutting at 1/42 veneer, it will
range
off the log at 1/41 to 1/43. That's a result of the wood being wet, then
run thru the veneer dryer. Now take that error and multiply it by 9 or 11
or whatever crossbands in a sheet of plywood.

If you have to have dead flat XX dimension, then you can order calibrated
plywood. Specify your thickness and your supplier "SHOULD" run it thru a
multihead sander and bring the entire panel down to .73 or whatever
thickness you desire. This way, you will ALWAYS have perfect plywood, at
least as far as thickness goes.

Naturally, you will pay more for calibrated core

John



"Mike Dembroge" wrote in message
om...
: For those of you that use a lot of plywood in your cabinets, casework,
etc,
: what do you find as an acceptable amount of thickness variance in your
sheet
: goods?
:
: My last 3 projects all used plywood of various species (A-1 Mahogany,
A-2
: Maple, C-2 Maple), and all was purchased from the same source: PALS in
: Oakland, CA. However, I found with each project that the thickness of
the
: plywood varied not only between sheets, but within the same sheet as
well.
: On my last project, I measured .009" difference in about 25" of length
in
a
: sheet. While this doesn't sound like a lot, it was enough to create a
: sloppy dado at one end and a too-tight-to-fit one on the other.
:
: Am I being too fussy, or is this normal? I spend a fair amount of time
: setting up the stacked dado set to produce a clean-fitting dado that is
not
: too sloppy and not so tight that it distorts the material. So, when I
make
: several cuts and some don't fit, it's a PITA.
:
: Mike
: Alameda, CA
:
: