How to Make a Miter Clamp

Making the Miter Clamp

• 1

  Measure and mark a point 3 inches along both edges of the long side of the two-by-four. Join the points, using one edge of the combination square to ensure that the line is perfectly straight.

• 2

  Measure and mark a point 1 inch in from the side along the short side of the lumber. Repeat the measurement at the other end and join, using the combination square for a straight line.

• 3

  Cut out the rectangle you have made using a saw, being very careful to keep the edges straight, and sand the cut edges smooth with sandpaper, keeping the angle at exactly 90 degrees. Brush off the sawdust from the lumber.

Fitting the Miter Clamp

• 4

  Fit the two parts of the miter joint together to check the edges are smooth and at the correct angle. Sand down to make the cut edges smooth.

• 5

  Place the larger piece of lumber outside the miter joint so that the inner cut edges butt against the outside of the joint. Check to be certain the fit is tight and exact.

• 6

  Fit the smaller piece of lumber inside the miter joint, pushing it up against the wood. Check that the two edges of the miter joint fit flush against each other then remove two pieces of lumber you've cut.

Using the Miter Clamp

• 7

  Glue the two sides of the miter joint and push together, fitting them flush with each other. Wipe off any excess glue with a cloth. Fit the two parts of the miter clamp in place, inside and outside the corner miter.

• 8

  Place one jaw of a bar clamp on the outer edge of the outside miter clamp and the other jaw on the opposite, inner edge of the inner clamp. Tighten until firm. Place the C-clamp over the other two sides of the miter clamp, on top of the bar clamp, and tighten; the clamps should form a cross.

• 9

  Leave the clamps in place until the glue has dried. Remove the clamps and the wood and repeat the process on the next miter joint.