You don’t need a belt sander to take advantage of a sanding belt. As shown in the drawing, I assemble a couple of 2x offcuts to create a sanding block that includes a variety of configurations. With this block I can sand inside and outside corners, flats, coves and oddball shapes with the slack-sanding portion of the belt. When assembled, the belt will not budge or slip, and its heavy-duty construction stands up to a lot of abuse. I keep one of these close to my block plane while I’m applying trim.
Robert F. Hausslein, Andover, VT