Hi Kevin,
Am I mistaken, or is "planishing" flattening the metal smooth.
What we are talking about here is a hammered finish, correct? Like
"ball peen".
Planishing can cause several different finishes, depending on how
up-tight you get about it.
In the generic sense, planishing does mean to flatten the metal, and
where you go from there depends a lot on the shape of the piece, and
what hammers you have.
“Normal” planishing hammers do have one very slightly domed face, so
technically, they are (very, very large radius) ball peens.
So step one planishing does leave a faintly ‘hammered’ texture. And
that’s as far as you can go on a flat thing.
Normal planishing hammers also have a flat (or very, very faintly
concave) face. On convex forms, like a goblet, you can use the
flat/concave face to knock the facets off in-between the divots from
step-1 planishing. If you get really uptight, you can go back and
shoot for the ridges in-between those hammer marks, until you get
an effectively smooth surface.
Any hammer can be a planishing hammer, if it’s the right curve to
fit the form, and it’s larger in radius than whatever formed the
thing in the first place. The ultimate goal is to generate
progressively wider and shallower hammer marks, to the point where
either you like the surface, or they’re easy to file level.
Planishing hammers should be very highly polished, just because
every mark on the hammer will get repeated onto the piece, every
time you strike it. Which means that it’s far simpler to polish it
out of the hammer, once, than polish it out of the piece thousands
of times.
My good planishing hammers are very highly polished, and are
covered with old socks when I’m not using them. Even on the rack.
Regards,
Brian
PS"> I do use a version of that 'ball burr hammered’texture (with
smaller burrs) on the backs of my production masters. It makes it
really easy to clean off/hide sprue marks, or anything else that
goes wrong. Flex-shaft textures hide a great many sins, when applied
intelligently.