Can Somebody Please Get the Foam?
For sanding irregular shapes, inside cuts, and rounded edges, you can't beat sandpaper wrapped around foam pipe insulation. Cut the insulation about 8" long, insert the edge of a piece of sandpaper into the slit in the insulation, and wrap it tightly. Secure the paper with masking tape.
The insulation provides backing for the sandpaper but gives enough to follow the contour of the workpiece. If you need more rigidity, insert dowel the same diameter as the inside of the insulation.
—Frank Ryan, Eugene, Ore.