On Jun 8, 8:15*pm, Jay Pique wrote:
Quite some time ago I had Morris make me up a clamping caul
"template". *Basically it's a 48" long piece of Masonite with a curve
cut on one edge to a radius of 2000.5 (inches, I believe). *The goal
was to have the ends be 1/8" higher than the center when place on a
flat surface. *Well just recently I got around to making the actual
cauls themselves. *I had a bunch of baltic birch rippings left over,
so I laminated three pieces together and template routed the curve
into one edge. *The finished dimensions are 1.5 x ~3 x 40". *I made
them 40" because that maximized usage of material, and because I
needed them for a 36" round table top. *I ended up making six of them,
and they really worked like a charm. *I used them in pairs, top and
bottom, but I suppose if you had a really rigid bench you could just
use one on top to push it flat. *In that case, though, maybe you'd
want them a bit wider - say 4" or so.

And, for those who think it ridiculous to go through the trouble of
obtaining a CNC'd template to make a clamping caul.....you're probably
right! *To me a fair curve seems like it should apply more even
pressure across the width of the panel, so that's why I wanted it.

Thanks, Morris!

JP

Screw a 1 x 2 to the edge of a straight board at the ends.
Push the middle of the 1 x 2 toward the board and
secure it with a third screw. Run the whole stack
through a tablesaw, ripping the bowed edge straight.
Unscrew the 1 x 2, watch it pop into a long curved
caul.