We asked four woodworkers and four home improvement editors the same question: “What is the best sander to buy for finishing cabinets”. And we got a unanimous response: “Buy a random orbital sander.”
All in all, there’s really nothing “wrong” with square-based, orbital finishing sanders. They “vibrate” the sandpaper in thousands of little orbits. They’re easy to control and they’re inexpensive to operate, since they use standard sandpaper in one-sixth, one-quarter, one-third or half sheets.
Orbital finishing sanders can leave small spiral swirls on wood if you’re not meticulous, but by sanding down through 180-grit, you can avoid this. But random orbital sanders take things a step further.
Random orbital sanders work far more aggressively and quickly. The circular bases spin at about 10,000 rpm while wiggling about 1/8 in. off center at the same time. This creates a truly random sanding pattern, which removes wood quickly and minimizes swirl marks. This speedy randomness also allows you to smooth joints where the rails and stiles of your cabinets meet at right angles.
Many woodworkers find they only need to go down to 100- to 120-grit paper with their random orbital sander for surfaces that will be painted or receive a clear finish. (For surfaces that are to be stained, consider a light hand-sanding with the grain to remove any and all remaining swirl marks.) But beware, the aggressiveness of a random orbital sander can cut through a veneer or damage the edge of a board in a flash. It takes a few tries to learn how to control them. Also, at a buck a sheet, the adhesive or Velcro-backed sandpaper discs are spendy, but you’ll work faster and wind up with better-looking cabinets.