"robo hippy" wrote in message
ups.com...

As far as drying I am still experimenting. I have used the alcohol
bath, LDD, and plain old air drying. I am starting to think that I will
end up going back to air drying. I don't really notice any advantage to
either of the bath methods, except that the LDD bowls do tend to sand
much easier. Success rate is the same for all methods. This could be
because of 2 things. One is that it is rather humid here and when put
on a wire shelf in my shop they dry at a nice slow rate. The other is
that I turn to finish thickness, rather that leave them thick, and then
return to final thickness. The thicker pieces will have more stress,
and problems releasing the stress. This is still an experiment in
progress, and I am still working on it.

Results are similar because it's still loss of bound water, not anything
done before it, that counts. We older folks who went through PEG and braces
across the center of bowls, for example, did get different results at least.
PEG was a clammy mess, and probably 25% of the braced bowls split.

As you've discovered, thinner deforms less than thicker, though not,
perhaps, as significantly as some think, because all shrinkage is local, and
there's less to grab onto on either side because of the curved shape of the
piece.

Try consulting the radial shrinkage table (or tangential for platters) on
the FPL site or Hoadley, and using it to determine how thin you can turn and
still come back to circularity at the desired wall thickness. If you're
impatient to dry, cut close to the minimum needed. Or add a bit more in
thickness to allow some changes if the shape you roughed isn't precisely the
one you want.

I've got a short stack of ~10" cherry bowls drying now that were roughed at
~3/4, and should give me 1/4 walls plus a bit of redesign room.