The drawing shows a trick that I teach my students for making perfect coped joints. We use water-based contact cement to glue a sheet of 220-grit sandpaper to a piece of molding that has the same profile as the workpiece. Result: a custom-made, contoured sanding block. Using the block to make a few back-and-forth strokes on the coped end of the workpiece will smooth out unsightly irregularities.
David Johnson, Clinton, IA
Edited and Illustrated by Charles Miller
From Fine Homebuilding #111