Maintain your clamps just as you do your tools. Clean the jaws, pads, and bars after a glue-up because hard, dried glue can dent workpieces and interfere with the jaw movement. And, once glue builds up, it is difficult to remove. To prevent this, put waxed paper between the clamp and workpiece. Or, apply a light coat of paste wax or paraffin wax to the clamp components to resist glue sticking. Add wax on the clamp screws for smoother turning. Do not use silicone- or oil-based lubricants: They can stain your workpiece and interfere with your finish.