Which sander should I buy?

Sanders look interchangeable and are not. The difference is the motion of the pad, and that determines both how fast each removes material and what marks it leaves behind.

Safety

Step by step

1. Buy a random orbital sander first.The disc spins and orbits at once, so the abrasive never repeats its path. That is what stops swirl marks. It suits preparation, finishing, paint removal and general work, which is nearly everything.
2. Understand what an orbital sheet sander is.Sometimes called a third-sheet or palm sander. The pad orbits in small circles without rotating. Cheaper, slower, and it leaves faint swirls that show under a clear finish. Fine for painted work.
3. Get a detail sander for corners.A triangular pad that reaches into corners, along beading and inside window frames. It is slow over any area and irreplaceable in the places a round pad cannot go.
4. Buy a belt sander only for heavy removal.Extremely fast and extremely unforgiving — it will dish a surface in seconds if you stop moving. For levelling floors, doors and large timber. Not a general-purpose tool.
5. Check the dust extraction.An on-board bag is better than nothing and much worse than a vacuum connection. If the sander takes a hose from a workshop vacuum, use it — dust control is the difference between a tolerable job and a miserable one.
6. Check how the abrasive attaches.Hook-and-loop discs are quick to change and cost more. Clamped sheets are cheaper and slower. Also check the hole pattern matches the pad, or extraction will not work.
7. Work through the grits in order.Coarse to fine, and do not skip more than one step. Starting at 80 and jumping to 240 leaves scratches the fine paper cannot remove — it just polishes them.
8. Let the tool's weight do the work.Pressing down slows the pad, generates heat and clogs the abrasive. Guide it and let it move at its own rate.
9. Keep it moving.Constant, overlapping passes. Holding a sander still in one place is what produces dips and burn marks, and it happens faster than people expect.
10. Budget for abrasives.Discs clog and blunt quickly. A worn disc does not sand, it polishes and heats. The abrasive is a bigger part of the cost than the tool over time.

Tips

• Corded is usually the better choice for sanding. It is a long-duration task and it flattens batteries fast.
• A block and hand paper still beats any machine for a small area and for final finishing. Not every job needs a tool.
• Vacuum extraction attached to the sander removes most of the dust at source, which matters far more than the mask.

Common mistakes

• Pressing hard to sand faster — It slows the pad, clogs the abrasive and generates heat that burns the surface. Light pressure and a fresh disc is faster.
• Skipping grits — Fine paper cannot remove scratches from coarse paper — it polishes them so they show up under the finish. Work through the sequence.

If it doesn't work

Questions people ask