Before making the first cut, a number of things have to be considered.
What kind of trim are you cutting? Different trims require different positions in the miter box or on the saw:
- In a vertical position, the back of the molding should be placed against the back of the miter box or saw's fence. This is used to cut baseboard, chair rail, quarter round and splice miters.
- For a horizontal position, the molding should lie flat on the saw table or miter box, decorative side up. This position is used when cutting window and door casings.
- A compound position is used for crown molding. Unlike other molding, the back of a piece of crown molding does not lie flat against the wall. Instead, it creates a triangular space between the wall and ceiling. A lower flat edge lies against the wall; an upper edge meets the ceiling. So, when cutting crown molding, it's the edges that rest against the fence and the table base, not the back of the molding. The decorative side should face down, the top of the molding should be on the saw table base and the bottom of the molding should rest against the fence [source: Carter].
Which piece are you cutting? Each molding joint has a left side and a right side. For a left-hand cut, most of the molding will be to the left of blade (when the finished side of the molding is face up, bottom down). For a right-hand cut with the trim in the same position, you're cutting the right side of the joint [source: Royal Mouldings].
What type of joint are you cutting? Spliced joints are 45-degree cuts. Coping joints require both a 90- degree and a 45-degree cut. Depending upon the tool used, mitering can allow more precise cutting. Because crown molding is installed at an angle to the wall, the angle of the molding needs to be taken into account. Detailed charts that specify settings for the saw's bevel angle and miter angle are based on the angles of the walls [source: DEWALT].
To find out the key tools you'll need to cut molding, read on.