It was somewhere outside Barstow when wrote:

Hmmm, about 1/4" bow. The board is 3/4 walnut and soft maple. There
should be enough thickness that it could be fixed.

My question was really "Why did it bow".

Most chessboards I've seen have been made in one of two ways;
sheetgoods (plywood, MDF, etc.) with veneer on it. Or else
glued-together blocks of contrasting timber. Now the glued-block form
may well distort, especially if poorly seasoned, but because it's
small block it should form small per-block ripples, more than one big
curve.

I've read that finishing the playing surface but not the underside can
induce stresses?

That's certainly a bad idea. The finish doesn't stress it, but it
changes the moisture absorbency. If one side is wetter than the other,
then that will certainly cause warping.

The bottom panel looks like ash to me and is
unfinished.

Bottom panel ? So this board sounds like a 2-ply lamination.
"Chequered" on the top (squares of contrasting timber), and a layer of
solid underneath. Now this construction is just a bad idea from the
outset - a two-sided lamination like this is asymmetric and will
_never_ be stable.

If you're going for this sort of construction, make it in 3 layers.
Duplicate the top layer on the bottom layer as well - it needn't be
chequered, but a plain veneer or one of the timbers would certainly be
a structurally good idea.


IMHE it's not worth repairing game boards like this. They either work
right from the start, or they're never going to work, no matter what
you do to them afterwards. Sand it flat in the winter and it might
just warp back the other way come summer. If it went wrong at all,
it's because the construction technique was wrong to begin with.

I'm not a chess player, but I do play go and make boards for it.
If you think chess boards can be expensive at the high end, you
haven't seen what a "good" goban sells for !

IMHE, there are two ways I make goban. One is traditional - take a
huge slab of a perfect tree, dry it carefully for years, then finish
the top surface beautifully by hand work. Some of these were
traditionally a "low table" in themselves, several inches thick and
with small feet so that they make the right playing height when
kneeling alongside.

Alternatively, veneer some MDF. This makes a _great_ board and is
little more than an exercise in simple plain veneering. MDF is simple
to work with, stable against warping and when around an inch thick it
has sufficient mass to be stable when playing. Go is a bit more
tactile than chess - the "feel" of the board is important when placing
stones. As before, veneer both top and bottom equally.

As a "thin" board (i.e. under 1") then I'd rather play on an MDF board
with a plain veneer top than on a solid timber board.



--
Inbreeding - nature's way of always giving you enough fingers to count your cousins