How to Make a Holdfast Clamp for Woodworking
The holdfast clamp dates back to the 1600s and was used during woodworking as a way to secure objects to a work table. These are very different from the modern day vice most modern woodworkers are accustomed to. Rather than having one piece joined by a connecting bar, holdfast clamps come in pairs and fit in to pre-made hole in the table. If you have a work bench, with or without holes for bench dogs, you can make your own holdfast clamp.
Disassemble your bar clamp. Take a common bar clamp and find the rivet that holds the main jaw to the clamp bar. The main jaw is the stationary part of the clamp that fits against the adjustable jaw. Using a hand drill, drill out the rivet and remove the stationary jaw from the bar. You should be left with an open-ended bar and an empty rivet hole on one end, and a moveable jaw.
Make bench dog holes. If your workbench doesn't have bench dog holes, take a piece of 3/4" thick plywood and cut it to fit the length of your workbench with a handsaw. Measure 1 1/2" from what will be the edge of your workbench with a tape measure. Mark the measurement with a pencil along the length of the wood. Along that line, drill a line of holes that will fit your clamp bar. These will overlap the edge of the bench and give you a place to insert the clamp bar.
Attach the metal strip. Take a small metal strip approximately 2 inches long and with a hole the same size as the hole in the clamp bar. Screw it into place using a machine screw and fasten the back end with a nut. When you finish, the metal strip should overlap the end of the bar by about an inch. You can crimp the end of the screw by bending it with a pair of pliers to make sure the nut stays on.
Things You Will Need
- Bar clamp
- 3/4" thick plywood plank
- Tape measure
- Hand saw
- 2-inch metal strip
- Machine screws
- Large pliers
- If you're using a holdfast with a workdesk that does not have dog holes, clamp both ends of your prepared piece of wood so that the holes overlap the edge by at least 1 1/2".
- Do not make your holes in the wood plank wider than the length of your metal strip.