Furniture Refinishing - Sanding
While stripping closes the grain of the wood to the penetration of stain and finish, sanding reopens the grain, evens out any discoloration that may have been left by a previous stain, and erases any scratches or blemishes in the surface. Get a perfect blank canvas to start from when refinishing old furniture by following these tips and techniques.
Margin of Error: Sand enough to obtain desired finish yet not enough to gouge the wood or sand through the veneer.
Most Common Mistakes
Sanding with an orbital sander that oscillates at less than 8,400 orbits per minute. This leaves swirl marks and scratches.
Refinishing requires time and patience. Plan enough time between steps to allow the glue to set and dry, the sanding to be thorough, and the finishes to dry properly. High humidity can more than double recommended drying time.
Gouging the wood with a belt sand in an electric drill—this can be tricky to fix, especially on finer pieces.
Best Sanding Practices
Most of your furniture refinishing will require a sandpaper of 100 to 120-grit. Change the paper frequently, as it is no longer sanding once it starts to wear out, rather polishing, which will close the grain again. To make your sandpaper last longer, use an old toothbrush to clean out the clogged debris.
For all-purpose refinishing, the ideal tool is an orbital sander that oscillates at around 8,400 orbits per minute. This speed assures elimination of swirl marks and scratches in the wood. I do not recommend a belt sander or sanding discs attached to a drill. These gouge the wood and leave obvious sanding marks.
You need not press down on the sander—its own weight will do the work. Just keep the pressure equal and guide the sander in even sweeps, always sanding with the grain. When sanding veneers, remember that most are very thin (1/32 of an inch thick), so be very careful.
Use a sanding block with 100 to 120-grit sandpaper for smaller areas. A rubber or padded sanding block has a little more give for odd areas. It also helps to have some different wood shapes (round, curved, etc.) available while you work. You can wrap the sandpaper around these when sanding curves or recessed molding. Remember to apply even pressure and sand with the grain whenever possible. Again, change the sandpaper frequently, and be sure to remove any glue that might have remained on the wood where you made repairs. Where wood dough has been applied, take care to sand the surface flush so as not to leave a halo when you stain.
Once the sanding process is complete you will want to clean the piece and the surrounding area thoroughly. Vacuum up all the dust and go over the piece(s) you are refinishing with a tack cloth to pick up any remaining fine dust.