Rene’
I would suggest a call to Rio and see what they say about what
you are doing. I am known for getting (or giving) more
on a subject than most people want, but in this case,
a call to Rio might get you info on materials and how “tight” you
might expect to roll the material.
We will be casting all day this Tues (I think!!) if you are in
the area or are interested.
John
John and Cynthia/MidLife Crisis Enterprises
Maiden Metals/C. T. Designs/Dach Ranch/etc.
PO Bx 44, Philo
CA 95466
Ph 707-895-2635 FAX 707-895-9332
If at first you don’t succeed, skydiving is not for you.
The early bird gets the worm, but the second mouse gets the cheese.
OK, so now I need to clean the rolls on my mill. They are
slightly damaged and I want to repolish them. I'm thinking
that I could sand them with a fine grit (600 or 1000) paper
Hi Virginia,
I assume these are very slight scratches you’re talking about?
Even so, I think you will need some even finer sandpapers than
600/1000. There are micro grit papers available from many
suppliers now - way finer than 1000 grit. I used them myself on
our shop rolling mill and they polished up the rollers
beautifully.
Elaine Corwin
GESSWEIN CO INC USA
Telephone: 1-800-544-2043, x287
Fax: 203-335-0300
They are slightly damaged and I want to repolish them. I'm
thinking that I could sand them with a fine grit (600 or 1000)
paper by just turning the rolls against a stationary object
that I faced with the sand paper. Then put some gold bob or
tripoli on rag and do somew more turning and polishing to take
out the scratches from the sand paper.
My personal opinion is that there is a potential to do a lot
more damage than the little bit of good that I could get by
polishing the surfaces. The little bit of pitting that my
rollers suffer only serves to give my rollers a little better
bite. If I owned a large lathe, I might consider resurfacing.
BTW, sometime in the past, I had grooves for wire rolling cut
into a couple of rollers. The machinist that did it told me that
the rollers were casehardened and that casehardening only ran a
couple of thousandths of an inch into the surface of the roller.
Might we be calling for new heat treatment if we remove too much
metal?
Bruce D. Holmgrain
Maryland’s first JA Certified Senior Bench Jeweler
@Bruce_Holmgrain
http://www.goldwerx.nu
703-593-4652
Does this sound like a good idea?
You’ll be at it forever that way. If you have access to a
lathe, you can polish them fairly quickly, spinning the rolls
against your succeding grades of emery paper. The big thing to
to be careful of is to be sure you work the whole width of the
rolls so they stay flat and parallel cylendars, without dishing
or unevenness. Since you’re not actually cutting metal here, any
lathe, even a woodworking one, can be rigged up to do this. Or
even a drill press, once you figure out the means to mount the
rolls between centers. Most already have center points in the
ends of the rolls, so it’s not hard to do. To help maintain
flatness, if you have to remove anything more than a slight
surface roughness, then you should consider not using flexible
paper or cloth for that coarser step, but instead a good flat
sharpening stone, like the ruby stone you use on your gravers or
the like. Make it one you can caress the entire width of the
roll with at the same time, usually by hold the stone’s length
to the rotating roll instead of it’s narrower width. if the
stone is dead flat as it should be, then the roll will stay that
way too. Remember, whether using a stone or emery paper, that a
little oil will speed the cutting action.
Peter Rowe
Hi Virginia,
Not me! Here are some of the reasons for that statement.
-
Mill rolls are usually hardened & sandpaper/silicone carbide
paper held against the rolls will take a very long time to remove
sufficient material to restore the roll.
-
The concentricity of the rolls is critical. Sandpaper by it’s
very nature has a soft backing & can result in the diameter of
the roll varying after being sanded.
-
Both rolls should be the same diameter when finished. Without
using a grinder that can control the amount of material that is
removed, achieving equal diameters would be difficult, if not
impossible.
I’d suggest finding a machine shop that’s equipped to do
cylindrical grinding & get a quote from them. Be sure you specify
the type of finish you want on the rolls. Depending on the type
of wheel used, the finish can be anywhere from highly reflective
to matte.
Dave