My partner had to trim out a half-round window this week. After cutting out the round casings with a jigsaw, he tried sanding the edges with a 5-in. random-orbit sander. He kept getting flat spots with this approach. So he started hand-sanding, with the frustrations that accompany folded pieces of sandpaper on curved surfaces.
Then he came up with the idea of reinforcing the sandpaper with a piece of copper flashing. He stuck a disk of adhesive-back sandpaper to the copper, and after a few minutes of sanding, the flat spots on the casings disappeared.
Jim Greene, Cookeville, TN
