It's the baking season again, and my wife brought out her tools yesterday. My annual job is to touch up the edge on her shape cutters. I thought I'd share my technique in case anybody else needs to do a little maintenance work.
What you'll need:
1) a marble tile, about 12"x12" - You can often get them cheap as open stock from Lowes/Home Depot type places, or from flooring/tile stores. You just need a broad, flat surface, so even a chipped tile would work.
2) metal sand paper - It's usually black in color. Grit will depend upon how much material you need to take off. I usually use 100-120 grit for the finish step.
3) a fine round file.
Place a sheet of sandpaper on the tile. Hold the cutter flat on the sand paper/tile. Move the cutter across the sand paper in a figure eight. Check the cutting edge periodically. When you see bright, polished metal all around, you know that the bottom is flat. Use the round file to gently remove the burrs that are pushed up by lapping on the sandpaper. Wash in soapy water to remove dust/shavings. You are ready to bake.
I also do this when my wife brings home a new cutter. Often there's a little step where the ends are welded together.