To answer Mr. Goodman's inquiry about sharpening punches; I have been
using this method, however crude it seems, for years with reasonable
success.

The first essential step is to insure that the new edge will be
perfectly 'flat' or square with the axis of the punch.  Hold the punch
at right angles to a stone and lightly grind off the old sharp edge.
During this procedure, frequently examine the edge, and stop grinding
only when a fine white line appears all around the entire edge.  This
assures that the business end of the punch is now truly flat.

Now lightly apply the punch at an angle to the belt sander, using a
slight twist of the wrist.  The punch should be held so the cloth runs
towards the point end.  Look at the end of the punch after every
application of the sander.  When the white line in the area being
sharpened just disappears, that part of the blade is as sharp as it
needs to be; then you can turn the punch to work on another quadrant
of the blade.

After the white line is all gone, trim off any burr inside the punch
barrel with a sharp knife point or a bit of rolled-up emery cloth.
A punch so sharpened can be kept keen for quite a while by occasionally
moving the blade forward with a slight twisting movement, on a fine
stone, or a sanding block with fine black finishing paper.

Richard Vance