Doug Miller wrote:


I think your first step ought to be to talk to the guy who made it
for you,
and see what he can/will do to fix it.

Can I find a planer at a furniture shop so big? Otherwise it looks
like
a lot of sanding is in my future.

Possible, but somewhat doubtful. You're *much* more likely to find a
cabinet
shop, or hardwood dealer, with a thickness sander wide enough to
handle that.
Post your location here, and I'll bet somebody chimes in to tell you
who to
contact.

You probably don't want to plane it anyway. Chessboards are usually
built with
the wood grain in the dark and light squares mutually perpendicular,
like
this:

||==||==||==||==
==||==||==||==||
||==||==||==||==
==||==||==||==||
etc

and no matter how you plane that (except diagonally, in which case
you'd need
a 30" planer) you're going to get some tearout. A sander avoids that
problem.

Probably, it will be necessary to shim it on the bottom side as it
goes
through the sander, to keep it stable and level. After one side is
sanded
flat, turn it over and sand the other side too. Try to remove an
equal amount
of wood from each face; otherwise, it's likely to cup again.

Once it's flat, you should use a random-orbit sander to remove the
ridges and
grooves left by the thickness sander. I'd start out with 100-grit
sandpaper,
then 150, and then 220. Apply the finish of your choice, and you're
done.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Thanks. I have some cabinet shops not so far away from me. Thanks for
the advice.