A master craftsman's experience with sanding techniques for wood materials

Jan 25, 2024

In this article today, let's take a look at the different ways of sanding techniques for wood.

General sanding steps

To efficiently sand boards, combine machine and hand techniques, sanding in sequence from low to high grit.

Start sanding with power tools and eliminate machine marks: Use a 5-6 inch diameter disc sander, starting at 150 grit and ending at 180 grit. Wear padded work gloves when using the sander to reduce vibration when the machine is in operation. Finish by hand sanding: After machine sanding to 180 grit, wrap 220 grit sandpaper around a cork sanding block and continue sanding by hand. The woodworker may scold you if you don't sand in the direction of the grain, but sanding at an angle of 7° to 10° to the grain removes the wood fibers better and doesn't leave any visible horizontal scuff marks on the surface of the wood.

Smoothing Larger Boards

For over 20 years I have been answering questions about woodworking processes and finishes, and one of the headaches that I am often asked is how to handle large boards that have been pieced together to get a flat surface. Often a put-together slab is too wide to pass through a flat planer, hand planning skills are not up to snuff, and a 5" disc sander on hand is too small to sand evenly.

My solution is to use a belt sander. Clamp two strips of wood with an 11⁄2-inch cross-section at the top and bottom of each end and in the middle of the board, tighten the clamps evenly, and rely on the pressure exerted by the clamps to flatten the board as much as possible. I would use a thin blade to scrape off excess glue, but sealing tape will work. Then tighten the steel rod clamps evenly and tap the boards around the splices with a rubber mallet to make the boards as flush with each other as possible.

Clamp the wooden strips at the front, back, and center of the board at the top and bottom respectively, and tighten the clamps holding at the top and bottom to exert pressure on the wooden strips, relying on the constraints of the wooden strips to clamp the board flat. Then tighten the clamps in the left and right directions of the board evenly in turn to make the board glued more tightly.

In spite of these precautions, generally, there will still be some unevenness between the boards, which will require the use of some heavy equipment. One of the first choices 4 * 24 inches belt sander, followed by 6 inches diameter disc sander can also be chosen, whether a cylindrical grip or gun grip can, although less efficient, the effect is not bad, but the premise is that the quality of your tools should be over the top.

Inspection of the sanding effect

A side light source will bring out the high and low spots on the panel. Use a low-angle light source to shine along one side of the panel to the other in order to see if the panel is flat. Dampen the wood surface. Apply an even amount of industrial alcohol, rosin or water to the surface of the panel so that you can see any sanding marks left on the panel or marks left by a flat planer.