bench grinder to sharpen tools (WAS Removing tool marks - Hydrochloric Acid)

["George Graham" <georgergraham@xxxxxxxxxxx>]

Dear Linda,

Some thought on using a bench grinder to sharpen tools. If your chisels are
traditional stone carving tools, then you can use any regular grinding wheel
that states it is for grinding steel. The wheels that cut cooler are fine,
but if you gently grind your tools, the regular wheels do just as well.
Never bear down on the wheel. Thin chisels will get hot very quickly. Tooth
chisels are particulary quick to burn. Once the edge turns bluish black the
temper is ruined, won't keep sharp and you might as well throw it away,
unless you know a blacksmith who understands retempering steel. If the edge
your grinding is too hot to hold in your fingers, your being to aggressive.
Some people like to grind away, and then dip the tool into a cup of water to
cool it down. In my opinion, your tools should never get that hot in the
first place.

Regular stone carving tools are made of soft steel as compared with
woodcarving chisels. They are soft but tough so they can take the hammering
and abuse. To reshape a dull chisel, I put the tool in vise, and use a mill
file to regain the proper taper and shape the tool had when it was new. The
last step is to use an oil sharpening stone to get a very sharp edge. This
sounds like a lot  of work, but it really dosen't take a lot of time or
work. You get a much sharper tool that carver much better, and you don't
risk ruining a good chisel.

Carbide tipped tools are the exception to everything I just said! A green
grinding wheel on a bench grinder is a must. I still grind very gently, and
never, never drop the hot tool in cold water. The sudden tempeture change
will crack the carbide! Just let the chisel air cool.

As you can tell, sharpening tools is very important to me. Carving with a
dull chisel is the single most common , and critical mistake you can make. A
dull edge breaks the stone instead of cutting. You have to hammer much
harder , which leads to deep bruise marks that show up late in the finishing
process. I like to have my flat chisel sharp enough to trim my fingernails.
To sum this up,, you can't cut stone with a dull chisel!
Good luck, George Graham