Here is a selection of some useful accessories that work with your clamps, to make assemblies and glue-ups go more smoothly:
Clamp pads protect workpieces from being dented by metal clamp heads. In lieu of making your own pads from scraps, you can buy rubbery plastic pads that slip over the jaw surfaces of various bar and pipe clamps. Rockler’s Sure-Foot™ conversion pads not only cover a pipe clamp’s jaws, but also raise and steady the clamp. Woodpecker’s magnetized clamping bars stick to any steel clamp jaw and distribute clamping pressure over a wider area.
Support blocks keep bar clamps aligned and steady during use. They’re included as part of both Bessey’s and JET’s parallel clamping systems. The JET blocks feature screw-on studs that fit into 3/4-in. bench dog holes, to help keep clamps in place.
Alignment devices help align parts and keep them from moving as clamps are applied. Woodpecker’s Clamping Squares and Box Clamps and Rockler’s Clamp-It® Assembly Squares keep frame and carcass corners perfectly perpendicular during clamping (Rockler also makes an adjustable Clamp-It® assembly tool, for angled corners). Lee Valley’s plastic right-angle assembly clamps don’t hold parts as rigidly, but they snap in place very quickly and easily. To keep boards and panels glued edge-to-edge flat during glue-up, Woodpecker’s clamping system includes sturdy flat bars as well as spring-loaded “Side Kick” clamps that straddle the glue line at the ends of the boards.