Keep Glue-Ups Flat with these Toothy Cauls
Build two or three of these serrated clamping cauls, and you can prevent a lot of sanding due to uneven glue-ups. Serrated teeth provide even pressure so boards don't ride up when you tighten the bar-clamp jaws.
Start by cutting 11⁄2 x3" cauls 8" longer than the width of the panels you wish to glue up. To prevent dents in the workpiece, use a softwood (like white pine). Run the edges that touch the workpiece over a jointer to ensure that they are perfectly straight. Next, cut the 45° tooth serrations about 2" apart and 1⁄2 " deep. Finally, drill the vertical holes in the end for the carriage bolts and attach the hardware.
To use the cauls, apply glue to the edges of your boards and assemble them, without tightening the bar clamps. Put waxed paper between the cauls and the workpiece to prevent the glue from attaching the cauls to the workpiece. Tighten the plastic knobs on the cauls, and then squeeze the boards together with the clamps.
—Jeffrey Anderson, Melbourne, Fla.