Some woodworkers might argue that a belt sander isn’t a tool often associated with fine craftsmanship. But the belt sander is a great choice for a number of everyday woodworking tasks. In fact, by using the proper techniques, a belt sander can save time and produce a dead flat surface. Of course, belt sanders can hog off wood at a surprising rate, so they’re not for use on delicate plywood veneers. But when it comes to leveling a glued-up panel that won’t fi t through your planer, a belt sander may be the best solution. It may not be the tool for a final finish, but it should still be a part of your sanding arsenal.
First, it’s a good idea to scrape off the glue squeezeout from the joints. The hardened beads of glue often have a soft center that will gum up your sandpaper in a hurry. A scraper does a great job of removing the squeezeout. When that’s done, I draw some pencil marks on the surface to help measure the progress. Then, I start with an 80-grit belt for most panels. This aggressive grit cuts quickly and makes short work of leveling the surface. For these first few passes, you’ll just want to keep the sander moving to avoid gouging the workpiece. Sanding across the grain will get rid of ridges and erase the pencil marks. Then, a couple of diagonal passes with a 100-grit belt levels the panel.
By this point, it should feel flat to the touch, but you’ll need to mark it to make sure. One way to do this is to use a straightedge and mark the low spots with a pencil. Then it’s just a matter of sanding down the high spots until the panel is level.
Finish with the belt sander by making a final pass using a 120-grit belt and moving the sander with the grain. This removes the marks left by the previous grits and prepares the surface for further smoothing with a random-orbit sander.
