Choosing a Random Orbital Sander
Sanding determines how a finished project looks more than anything else. The sander is not the place to economize, and the choice is narrower than it seems.
Why random orbital
A random orbital sander combines a fast rotating disc with an offset orbital motion. The randomness prevents the swirl marks a conventional disc sander leaves, and the offset breaks up the scratch pattern so successive grits smooth each other out.
Orbit size
| Orbit diameter | Use |
|---|---|
| 3/32" (2.4 mm) | Final finishing passes — the finest cut |
| 7/32" (5.5 mm) | General purpose; the default choice |
| 3/16" (4.8 mm) | Middle ground |
Pad diameter
- 5 inch — corners, edges, flat surfaces, and plenty of control
- 8–10 inch — large flat surfaces fast; awkward in corners
Most furniture work is a 5 inch pad. Large flat panels like tabletops are where a bigger pad pays off.
Features that matter
- Dust collection — a bag or a port to a shop vac. This is not optional; airborne sawdust is a health problem and a finishing problem.
- Variable speed — slower for final passes and delicate work, faster for stock removal.
- Rubber pad — much better grip on vertical surfaces and fewer accidental drops.
- Trigger or paddle — a variable trigger gives more control on curves and edges.
Grit sequence
| Situation | Sequence |
|---|---|
| Raw ¾" plywood | 80 → 120 → 180 → 220 |
| Hardwood furniture | 120 → 180 → 240 |
| Stripping finish | 36 → 60 → 100 |
| Between finish coats | 180 → 220, and nothing coarser |
A separate, dedicated finish sander is worth it. Loading a coarse-grit sander with fine dust and then accidentally using it for a final pass is how scratches appear on a finished surface. Use cheap discs for stock work and a good sander with fresh fine paper for the last pass.
Air management
A random orbital sander with dust collection connected to a shop vac beats one with a bag, and both beat none. If you have a dust collector, a 2½ inch hose adapter lets you connect directly. A brush skirt on the pad collects dust while you work and lets you reuse the paper a few extra times.
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