DIY: Picture Frame Clamp

Cut four 2-inch squares from ¾-inch thick plywood on a band saw. Mark diagonal lines through each piece from corner to corner in each direction. Use a rafter square to mark lines through the center of the block from side to side in both directions. Drill two ¼-inch holes, one in the center and one halfway between the center hole and one outside corner, on the diagonal line. Cut the opposite corner of the block from the second hole, 1 inch by 1 inch so that the inside corner of this notch ends at the center hole.

Cut four pieces of 1 by 2 hardwood lumber 16-inches long. Draw a line down the center of one wide face of each piece. Use the rafter square to mark every two inches along this line. Bore a ¼ inch hole in each mark.

Cut two pieces of 2 by 2 hardwood lumber, 4 inches long. Mark the center of one face and drill a ¼--inch hole through the piece on this mark. Turn the piece one quarter turn to an unbored face and draw a line down the center the long way from end to end. Measure and mark 5/8-inch in from either side on this line and bore a ¼-inch hole through the piece. Repeat with the remaining piece.

Attach one 2 by 2 block to one end of two of the 1 by 2 pieces with a 2-½ inch carriage bolt and wing nut. Put the bolts through the end holes on the 1 by 2 pieces and through the holes you bored 5/8 inch from either end of the 1 by 2 pieces. Repeat with the remaining 2 by 2 and 1 by 2 pieces. Thread a 3-inch carriage bolt through the center holes of the two 2 by 2 pieces and twist a washer and wingnut onto the end to hold them together.

Attach the four notched 2 inch blocks to the tops of the 1 by 2 pieces, one on each 1 by 2 at the same hole out from the center with a 2 inch carriage bolt and wing nut. Choose the hole that is closest to the frame size you need to clamp. Fit the four pieces of your picture frame into the clamp, one corner in each notched block. Twist the wing nut on the center 2 by 2 blocks clockwise to tighten the clamp.