Belt sanders work in their own dust, which is why they wear. Fine dust gets into the rollers, the tracking mechanism and the motor, and the platen behind the belt wears with every hour of sanding. A sander that tracks badly, runs hot or eats belts usually needs cleaning or a cheap part, not replacing. Your manual has the parts list and service intervals for your model.
After use.
- Blow or vacuum out the dust from the rollers, the tracking mechanism and the motor vents. A vacuum is better than an air line, which pushes dust into bearings.
- Empty the dust bag or clean the extractor. A full bag means the sander can’t clear its dust, so it runs hotter and the belt clogs.
- Clean the belt with a cleaning stick if it is loaded; see sanding belt problems.
The platen and its pad.
The platen is the flat plate behind the belt that you press against the work. On many sanders it is covered with a cork or felt pad, a graphite sheet, or both. When the cover wears through, the belt drags, heats up and stops sanding flat. Replacement pads and graphite sheets are cheap; check the parts list for your model.
Rollers.
Spin each roller by hand with the belt off. It should turn smoothly and quietly. Grooves worn into the roller surface, a rough feel or play in the bearing all make belts wander. Many rollers are replaceable parts.
Carbon brushes.
Many corded sanders have brushed motors with carbon brushes that wear down over time. Worn brushes cause sparking at the vents, loss of power or a motor that cuts out. Some sanders have caps on the outside for changing them; others need a service centre. Replace both brushes together with the correct part for your model. Brushless cordless sanders don’t have them.
Bench sanders.
- Table: keep it square to the belt or disc and the gap small; see shaping on a bench sander.
- Disc: replace worn or lifting discs, and clean old adhesive off the plate before fitting a new one.
- Tension and tracking: check that the tension lever holds and the tracking still adjusts smoothly.