When boards that are placed on a slope meet at a corner, you can’t simply cut the ends to 45 degrees to make a miter cut. The joint must angle in two directions called a compound angle or angled bevel cuts. Angled bevel cuts can be cut in two ways, one for the narrow boards and the other one for the wider boards. The first method, which is used for narrow boards is very simple. Place the board in the miter box on the angle that it will be in the finished product. For the second method however, there are steps to be followed as enumerated below.
- Determine the angles you will be using. This is necessary in setting up the blade and the miter gauge. Determine first the angle of the slope. You can determine the angle by setting a sliding T-bevel to the desired angle, and then placing the bevel against a protractor and reading the angle where the blade crosses the scale.
- Make the cuts on the table saw by using the miter gauge in combination with the blade tilt. Refer from the chart to determine the angle to be set for the miter gauge and the angle of the blade tilt. An example of a square cut for a 5-degrees side slope—the miter gauge is to be set at 85 degrees while the blade tilt should be 44.75 degrees. Both the miter gauge angle and the blade tilt angle in the scale uses 90 degrees to indicate a square cut. If the scale on your saw uses a 0-degree to indicate a square cut, then convert the listed angle by subtracting it from 90.
- Cut the parts to rough length with the blade and miter gauge set to make a square cut. Then find the correct angles on the chart, depending on the angle of the side slope. Set the miter gauge and the blade tilt to the angles listed. Cut one end of each part using the set angles.
- Reset the miter gauge to the same angle, but on the opposite side of 90 degrees. Make the second cut on each board using the set angle.
- To assemble the miter, clamp one part in a vise and apply glue to the joint. Hold the mating part in place and drill pilot holes. Drive nails, dowel or splint into the joint.
The miter joint is the most frequently used joint in finishing carpentry. Miter joints are used for door casing, window trim, baseboards, and ceiling moldings. Door casing and window trim normally use a standard frame miter. This kind of joint is also used to make cabinets, when you don’t want any end grain to show. Miter is most commonly used to join the sides of a cabinet to the top. Since miter is the most common wood joint used in finishing carpentry, it is just but necessary to know the proper way of cutting the stock to be mitered.