DO IT YOURSELF
When cutting trim, a higher number of teeth generally trans- lates into smoother cuts for finish applications. The type of material is also a factor; for cutting PVC product we recommend using a carbide toothed blade with 80 teeth or more to prevent chipping. A blade designed specifically for the application can increase the accuracy of your trim cuts, which helps when mating the joints. A rough cut might require you to sand the cut smooth, but the act of sanding can alter the shape of the cut, so it may no longer fit perfectly during assembly. Spare yourself the frustration on trim projects and use fine-toothed blade intended for trim.
STOP, CALIBRATE If you’re using a Power Miter Saw it is important that the saw is calibrated (checked for accuracy) before you start cutting. This is an important step because a 1° dif- ference over a 1-in. span will result in a 1/32-in. gap in the fin- ished miter joint. ( 3° over 5-in. span gives you a 3/8-in. gap.) Use a combination square to confirm the blade’s miter and bevel align- ment, adjusting if necessary. Check your saw manual for specif- ic instructions on how to adjust
the blade, which may involve loos- ening/tightening a series of set screws or bolts.
CUT TIGHTER MITERS
WITH ANGLE CALCULATOR Trim installers quickly learn that not all corners are truly square. it is not uncommon for the wall angles of a house to be off as much as 3°, which can result in a gap in the miter joint. To solve this problem
when cutting Vertical Position Miters (base board, chair rail, quarter round, etc.), you should measure the angle then refer to an Angle Calculator to determine the two complementary angles needed to close the joint. (See “Miter Angle Calculator Chart.”) For example, an Inside Corner with an angle of 87 degrees will require two intersecting 46.5-degree miter cuts to close the joint.
Calibrate the saw for angle accuracy, otherwise your cuts might be off. Refer to this chart to determine complementary miter angles if the walls are out of square.