In this video, This Old House general contractor Tom Silva explains how to cut miter joints.
How to cut miters
- Use traditional wooden miter box and backsaw for making simple 45- and 90-degree miter cuts.
- Lay molding in box and hold it tight against back fence.
- Set saw in appropriate slots, and make cut with slow, smooth strokes.
- To hand-cut a wider range of miters, use an adjustable miter box with backsaw.
- Rotate the saw to the desired angle, lock the saw in place, then make the cut.
- When extreme precision isn’t required, you can cut 45-degree miters using a portable circular saw and speed square.
- Hold the square against the board, then guide the saw along the square to make the cut.
- For the optimum miter-cutting accuracy and ease, use a compound-angle power miter saw.
- Rotate the saw blade to the right or left for making straight miter cuts.
- Tilt the blade for making bevel cuts; note that some saws only tilt to the left, but dual-bevel models tilt both left and right.
- Set the miter angle and bevel angle at the same time for making compound-angle cuts, such as those necessary when installing crown molding.