On Tue, 22 Sep 2009 07:50:11 -0700 (PDT), Andy Dingley
wrote:

Double-ended coarse/fine fast grinders with small wheels are OK for
most metalworking applications, such as cold chisels

Cold chisels and sds chisel bits were what I had in mind. It sounds as
though for these types of chisel a dry grinder is ok but if I wanted
to sharpen wood chisels I would need a water cooled one?