Tin snips get dull, just like every other edge tool in the builder’s toolbox. But the right way to sharpen them isn’t widely known. The drawings above right show how I sharpen my aviation-type metal snips.
First I take the jaws apart by removing the screws that hold them together. Next I hone the meeting edges of the jaws on a piece of 220 wet/dry sandpaper placed atop a glass sheet, as shown in the drawing.
The last step is to serrate the outer edges of the two jaws with a double-cut file. The trick here is to remember that the file will leave serrations when used in one direction but not the other. Use moderately hard, short, downward strokes to cut the teeth. In the drawing shown here, the file moves from right to left, or heel to toe. Reassemble the snips, and they’re good as new — maybe even better.
Tom Law, Westminster, MD