Get wedged in when edge-gluing thin stock
A luthier friend, who makes stringed instruments, showed me this tip for gluing up thin panels and keeping them flat using large wedges, straight cauls, and strong cord.
Start by arranging the cauls on the workbench to support the workpieces. Apply glue to the workpiece edges, lay the pieces across the cauls, and wrap the cord in a figure-8 pattern over the workpieces and around the cauls underneath, leaving a bit of slack. Then insert a wedge between the cord and workpieces directly over the caul. Repeat this process down the length of the workpieces, alternating the taper direction.
To clamp, gently tap the wedges in deeper, a bit at a time. The downward pressure pushes the pieces against the cauls and together at the glue joint. After the glue sets, tap the wedges back out.
—Keith Mealy, Oregonia, Ohio