When gluing up boxes using band clamps, I like to put blocks that help align the sides and spread the clamping force at each corner. Lacking enough hands to hold all the blocks in place, while at the same time tightening the band clamp, drove me to devise this simple solution. Using some scrap ¾" plywood and ½" hardwood dowels, I made a set of four self-standing adjustable corner blocks.
Start by cutting four 10" lengths of dowel. Cut the plywood into a dozen 3" squares, then cut a 1" square notch out of each corner. Drill a ½" hole in the opposite corner from the notch. It’s helpful to stack and clamp each set of three blocks when cutting the notch and drilling the hole, to ensure that each corner block is perfectly aligned.
Glue a dowel into the bottom square of each set, leaving the other two squares unglued and free to slide up and down the dowel as needed.
Because the base square is glued into place, the corner block set will stand in place, allowing me to concentrate on positioning and tightening the band clamps.
