Hi Orchid, I am also new to mass finishing and have just purchased a
used vibratory polisher, along with steel shot, medium and fine
plastic pyramids and some green buff. My designs are Argentium in
sort of a heavy filligree style and involve some forging, granulation
and soldering of bezels (Argentium and 18k) and jump rings after
casting. Until now I’ve been giving them an initial clean-up with a
400 grit bristle disk before forging and fusing the granules, then
polishing up to a fine bristle disk, soldering bezels and jump rings,
then high polish and set the stones with a finalpolish and cleaning.
What I’m wondering is how to adapt the process to mass finishing… ?
Where does the steel shot fit in? How well do bezels standup to this
process? Will burnishing deform or harden the bezels to an
unacceptable degree?
You will love mass finishing for this kind of work. And you have
good equipment for doing it. If your tumbler will accommodate a
flow-thru process, use it.
After the initial clean-up, put the pieces in your tumbler with
medium abrasive pyramids, a cleaning liquid and run for 4 to 6 hours.
Rinse well and repeat with the fine grit abrasive pyramids.
If you got enough steel shot to fill your tumbler 75% full, run your
pieces in that with the appropriate liquid. - I’m a bit cautious here
because the tumbler needs to be rated for steel or you will burn it
up. A better solution is a small inexpensive rotary tumbler to run
the steel. That is a 30 to 45 minute run in either rotary or
vibratory tumbler. The issue here is that small amounts of steel in a
vibratory tumbler just jiggle and don’t do the burnishing work.
Then back to your vibratory tumbler, cleaned very well. For a high
polish, run your pieces in the green buff for 24 hours or more. When
finishing planished chains, it often takes 2 days to get a mirror
finish. You can re-charge green buff with chrome oxide paste or from
your auto parts store, Simichrome.
Here’s the good part - finishing with your tumbler will preserve all
the texture and granulation work without removing detail. Bezels of
28 gauge fine silver or thicker do not deform. Do not over load the
tumbler with work. About ten or fifteen percent of the volume of
jewelry will keep impingement to a minimum. Deformation is a concern
when you don’t have enough media to cushion the work. Vibratory
tumblers need to be loaded with media 75 to 85 percent of volume. If
you run with insufficient volume, you will get dents and deformation
of your work and the process won’t work to smooth your work. I don’t
find that the bezels are particularly hardened with the process.
I think that folks object to mass finishing hardening bezels when
they run steel too long. In a proper load, and run for half an hour
or so, it isn’t a problem. Running work in steel for two or three
hours will certainly harden bezels. Just don’t do it.
I wrote a small book available from Rio Grande, Otto Frei and others
“Tumble Finishing for Handmade Jewelry”. It would help you
understand the process and techniques.