How to Sand Wood

Combine Power and Hand-Sanding for Good Results

Proper sanding is a crucial part of woodworking, so some tips and techniques for wood sanding are necessary.

Those who rely solely on power tools will inevitably be left with planer- and jointer-knife marks and fibers crushed by the feed rollers. Router tables can leave gouges and scratches, and assembly often produces some errant glue splotches. All of these blemishes should be removed before a finish is applied, and sanding is the best way to achieve this. The most efficient way to sand a surface is with a combination of power-sanding and hand-sanding.

Power-Sanding Comes First

Of course, you could do all of your sanding by hand, but why? Even if you use power sanders wherever practical, there will be enough hand-sanding on almost any project to give you plenty of hand-done satisfaction. Power sanders deliver results with much greater speed, and with minimal practice they'll also deliver a flatter surface than sanding by hand alone.

The good news is that unlike much of your other shop equipment, quality sanding tools will not cost you much. I strongly suggest you get a random-orbit sander. A pad sander also is useful, and I'll explain why a detail sander is optional. Don't forget a dust mask and hearing protection.

Use the Right Grit From Start to Finish

With either type of sander, You'd better start with 150-grit than 120-grit paper on most pieces, even though it may take longer to remove some milling marks. For wood that is already in good shape, especially thin-veneered sheet goods shall be started with 180-grit paper. (Note: The grits refer to here are based on the Federation of European Producers of Abrasives (FEPA) scale, which uses the prefix P, rather than the alternate Coated Abrasives Manufacturers Institute (CAMI), or C, scale)

Don't continue using a piece of sandpaper until the sand is all gone and there isn't anything left but the paper. That's a false economy if you're charging for your time; Move to a fresh section of sandpaper as soon as you feel it stop cutting or start to clog, or when it requires you to exert more pressure. Besides, it's important to vacuum and/or blow off the entire piece between grits.

Final Hand-Sanding is a Must-Do

No matter how much you are able to use machines for the initial stages of sanding, you'll want to give each surface some final sanding by hand. Primarily, this is to get rid of the small orbital scratches left by the machines, replacing them with smaller, finer scratches that are all parallel to the grain of the wood and hence less noticeable.

You should back up the sandpaper with a sanding block or insulation foam cut to fit your panel's profile wherever possible to maintain a flat surface. The palm-sized rubber blocks are usually most convenient because they also can be used for wet-sanding between coats of finish. Other choices include cork blocks or wood blocks faced with a sheet of cork.

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