The last step to success in gluing up a perfect box joint is clamp-ing. If the fingers stand proud of the sides, you can't really apply clamps directly on the corners to pull the joints tight. We earn from qualifying purchases made through affiliate links. Gluing up box joints can be a tedious job, but there are a few things you can do to make the task easier. To help you succeed at your next clamping assignment, I'll tackle the most common glue-ups, including flat panels, casework, and mitered. When making box joints, per a number of articles I've read, I've left the fingers a touch longer than the thickness of the board. So if I'm making joints on 1/4" plywood, my fingers might be 5/16" long, and then I just sand them down at the end. If there are gaps or the joint slides together too easily, then the. Nasty stains can occur during glue-up if steel clamp beams are left in contact with wood dampened by glue squeeze-out or by scrubbing off the glue. Their inner surfaces are laid out with alternating pin-and-slot patterns to match whatever common joint I'm making — 1/4″, 3/8″, 1/2″ or 3/4″.
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