UNCLE!!! I've DAGed and Goggled and haven't come up with what I consider a
good answer to the question of what to use to flatten Arkansas stones...
I've got quite a collection of stones, accumulated over about 35 years,
ranging from large soft stones to a large Black hard stone, along with
assorted slips, etc. The soft stones in particular are no longer truly flat
and the medium stones are a bit glazed.
Why Arkansas stones? Because when I started buying stones they were about
the best thing available... India stones were the other choice and those I
used were all glazed--I "found" them in my father's tool and die maker's
tool box. ;~)--and they didn't work too well.
I'm considering the Woodcraft granite surface plate and wet-dry paper
approach but wonder if a diamond stone would be better? I'm concerned that
the courser diamond stones may actually make my medium and fine Arkansas
stones too rough. Is there a consensus?