Pipe-Clamp Cauls Put Pressure Where You Need It
These clamp cauls not only position edge-glued stock at the center of pressure on the pipe clamps, but they also help spread the clamping pressure along the length of the workpiece and protect the edges from bruising. They make the clamping process much faster and easier.
To make them, first bore a hole (sized to slip over the pipe) about 1 in. from the edge of a 2×4. Then cut a 3/8-in.-deep rabbet in the 2×4 wide enough that the clamp head is centered on the edge of the material you’re gluing up. This width will vary with stock thickness. This puts the clamping pressure right where you need it.
The cauls I use most of the time are 10 in. long, and I keep them on my pipe clamps. But I have longer and shorter cauls for different-size jobs.