Make your own frame clamps

When you are making picture frames or projects that require corner clamping, these homemade frame clamps allow you to do away with straps and large clamps. The clamps are designed to fit into any corner and allow you to use standard quick clamps for securing glued frames.

 

instructables.com

All you need to make your own frame clamps are some offcuts of plywood or supawood that are about 100 x 100mm square. Cut 4 pieces exactly square using a jigsaw, mitre saw or table saw. They do need to be perfectly square or your frames won't sit square.

Divide the blocks diagonally into two sections. The holes need to be about 20mm in from the edge and far enough apart to allow for two clamps to be used simultaneously, so allow about 80mm. Use a drill press and MAD or Forstner bit, or a drill and hole saw, or even a router and Forstner bit to drill out 40mm diameter holes.

Not absolutely necessary, but cutting off the corner allows any excess glue to squeeze out when clamping.