A belt sander is used as a preliminary step in the sanding process, bringing rough, coarse wood to the point where it can be further refined by a smaller and more precise hand sander. Most semiprofessional and amateur woodworkers use belt sanders with a 21-by-3-inch belt. Use safety goggles and a respirator to protect yourself from dust.
Never use a belt sander with a belt that's worn or frayed. A belt that snaps while the sander is in operation can flap violently and strike you on the hands, arms or face, causing severe injury.
If you're replacing a worn belt, install only sanding belts that are the same width as the pulley drum of your belt sander, and periodically adjust the tension of the sanding belt to make sure it's running at the same speed as the pulley drum.
The dust collection bags and exhaust systems on a belt sander serve a valuable purpose. Never use a belt sander without a dust collector or some sort of connective exhaust system. The large amounts of dust from a belt sander cause potential fire and explosion hazards. Breathing in large amounts of dust is also a health hazard. Proper ventilation is essential.
Empty the dust collector on your belt sander when it is 1/4 full, as the collector will fill up fast while in operation.
Use two hands on a belt sander when it's in operation. Place one hand on the trigger switch and the other on the front handle knob. Keep your hands away from the belt, the driveshaft and the pulley not only when the machine is in operation, but also when it is off yet still plugged in. Never try to rotate the belt with your hands while the belt sander is off but plugged in.
Securing the Object to Be Sanded
Never use a belt sander on an unsecured wooden object unless the object is large enough and heavy enough to stay in place, for example, a door laid on a secure work surface.
Secure smaller objects that might not stay in place when sanded with clamps. Smaller pieces that are not sufficiently secured during belt sanding can very quickly become dangerous projectiles and cause severe injury. Avoid sanding pieces which are simply too small to adequately clamp down, and never use your fingers to hold down small pieces while attempting to belt sand them.
How to Apply the Sander Once Started
Belt sanders should be in motion before they ever touch the surface of the wood to be sanded. Never start the belt sander in a resting position on any surface. Hold it suspended in the air until the belt has reached full rotational speed, then lower the belt sander onto the work surface with a slight forward motion. Let the rear roller make contact with the work surface first, bringing the rest of the base down as you start moving the sander forward.
Remember that the handle at the back of the belt sander is for controlling it, while the front handle is for guiding it. Move the belt sander back and forth, parallel to the wood grain, without pressing down on the sander.