Sharpening disc punches

Carla, you cant really use most sandpaper unless you have an
absolutely flat surface & it is more likely to dull than sharpen
them… However- 3M makes a brand of polishing papers and films that
are great for exactly this purpose…not sand-paper but microfine
particle papers, most distributors carry them, or write to Rich Boer
at 3M’s creative arts division and request some samples…they come in
a variety pack of, I think about 8 grits and are colour coded. I
think they tri-m-ite or either tri-zact, the films are ready to load
on holders or come in a psa sheet for applying to glass, which is
probably about as flat as you’ll get readily and cheaply without a
machined steel block…Just adhere the papers to a sheet of glass (
tape the edges with blue painters type tape for safety) and with the
cutters as vertical as is possible pass them over the surface as
long as you care to. The theory is to go from coarser to finer papers
and with the 3M products using only a grade or two is all you’ll
really need to restore a perfectly honed edge. If the punches/cutters
are out of shape (perfectly circular), and worth the cost of taking
them to a machine shop, you may want to have them re-turned to remove
any nicks or flares you may have gotten from trying to cut metal
materials harder than the punches. also if you live in a humid area
don’t forget to coat them with some type of water proofing oil or
wax, or dry oil ( readily available at hardware stores) as rust is
the most common ruination of most shop tools that were once polished
nicely! Keeping a keen polished edge on them is relatively easy as
opposed to resharpening them and the 3M products out preform any
other products i have tried in many years of -trying! If you can’t
find the exact name of the films or papers I’d be happy to look them
up for you as I’m in another part of the house at the moment but
have lots of packets of the stuff in the studio…let me know.
Additionally, there is a great book you may want to get for general
reference"sharpening small tools, by:. Ian Bradley…it may help you
maintain other things in your shop that you hadn’t considered.

you cant really use most sandpaper unless you have an absolutely
flat surface & it is more likely to dull than sharpen them... 

There is absolutely no way you can hold the punches flat and square
enough to get a sharp edge by hand you will round the edges no matter
what paper or film you use. For this problem you really must have a
machine tool to solve it, a surface grinder, tool and cutter grinder,
a lathe with a tool post grinder there are several ways to do it but
by hand is not one of them.

James Binnion
James Binnion Metal Arts


Hi Carla,

One of the important things to remember when sharpening a punch
system is that the faces of the punch & die be parallel to each

Generally this can’t be guaranteed when sharpening by hand with
sandpaper or polishing paper.

If it were me, I’d take the set to a machine or sharpening shop that
has a surface grinder. They will be able to keep everything parallel.