cutting corners

“Turning the corner” is easily the most challenging part of any moulding installation or repair. It helps if you aced geometry in high school. For all others, learn to use a miter box, preferably one with a clamp. More experienced? Upgrade to a compound miter saw.

A miter box is a three-sided wood or plastic tool with open ends, which allow pieces of moulding or millwork to slide into position. It’s used with a backsaw, a rectangular saw with a reinforced spine that keeps the blade rigid. The saw fits into vertical slots in the miter box, set at the precise 45 or 90-degree angles needed to cut miter joints. You’ll need to cut a host of them if your job includes areas where the moulding turns at an outside corner.

To miter trim at an outside corner, cut two pieces of moulding at mating 45-degree angles. Fit together to form a tight right angle. It’s OK if there’s a slight gap at the back of the joint; it’s the “show” side that’s important. For mouldings to be installed flush (resting on the surface of the wall), nail the two mitered sides together with small finishing nails. If the moulding is sprung (installed at an angle to span perpendicular surfaces), glue the joint together.