I disassembled an old Volume pot and I used the stem to mount the knob on and then chuck it up in the Dewalt drill and spin away wile using the green scratchy to ""Buff" out the scuzz. I've had some that were so bad I had to start with 320 paper............. Since they didn't actually come with a mirror finish on them, the green scratchy can get them clos eto the same finish just by varying the speed, and finishing up with a new stiff green one.