Can any one suggest the usage of magnetic polisher, vibrator with
steel media, and buffing. My thing is which one should be used
first, second and third, to get the best result. And some
important about the recovery aspect of gold from
buffing and the preparation of the flux.
A usual sequence for mass finishing would be first to run abrasive
media to smooth - this may be one or two steps depending on how much
grinding is needed. Then burnish with Stainless steel or ceramic
media, then to buff with a mixture of wood chips, wood pegs and a
polishing compound appropriate to the metal being finished.
If you are processing very detailed work, a preprocess step might
include the magnetic pin finisher to burnish the details that the
coarser media can’t touch.
This presumes that you want a conventional bright finish. For
brushed, textured, stippled or other specialty finishes, you would
use some of these steps, but not all.
As to metal recovery, the only time you will generate scrap would be
in the abrasive steps. The liquid that I like to use is a
non-chelating compound that will capture and settle the precious
metal. After a day of settling, I pour off the top clear water and
pour the remainder cloudy stuff into a flat drying pan. Evaporation
occurs, and then you add the white stuff to your sweeps and process
as normal. You can usually run 8 to 10 batches using the same rinse
before you have to start over with new solution. Depending on how
nasty the work is, etc.
One of the major advantages to mass finishing is that it removes a
very small percentage of precious metal as compared to hand
finishing. The numbers I’ve been quoted are 0.05% for mass
finishing as compared to 5 to 10% for hand finishing. While those
numbers are probably not exact, the proportion saved with mass
finishing is substantial.
For more see my website for a book on the subject.
Orchid supporters such as Rio Grande, Gesswein, Otto Frei, and
Elaine Luther at Creative Texture Tools can supply the book, Tumble
Finishing for Handmade Jewelry: Small Scale Mass Finishing. 4th
Judy Hoch, G.G.