i do the transition from shelf to window with a chainsaw file, so than i stay away with other rasps and files at least that far- so i dont need to get right in the corner.
i did mine first so the riser id still a nice solid block- easy to clamp in the vice- then i make sure i always have two hands on the tool :eek:
i also made a block with a flat back, and a concave surface to match the bows back- so i dont damage the back of the bow during clamping- spread the load evenly- and i have wooden jaws for my vice.
another thing i do- say for the shelf- if i only want to file in say 1/2 " my file is 1.25 wide- well i hold my left hand on the side, (with my right being the main power stroke with the file),so that my fingers curl under the file, and grip the file underneath and thumb on top to act like a guide against the riser, so that the file cant go too deep.
and go slow-
just what i do- hope it wasnt too boringly detailed.- no insult intended- just explaining
wayne