I was wondering if anyone had any info on DIY tumble polishers. My
idea was to get a kiddies rock tumbling machine, which are quite
inexpensive, and some plastic media finishing pellets and give it a
go for pre-polishing of sterling silver. I usually do all finishing
by hand with my foredom and this seems like a neat way to suit my
pre-finishing needs. Is this idea possiblei Also, if anyone has any
info on the those polishing pellets it would great.
I would not recommend the children’s’ tumbler as these kits don’t
stand up very well to use. Your money is better spent on a small
Lortone tumbler as they are much more reliable and even have some
resale value later in a garage sale. In addition, it is easy to order
replacement parts for these hard working machines. Most rock shops
carry machines from this company.
I have a few home built tumblers, both rotary (as in rock tumblers)
and vibratory. Rotary ones are more gentle and require much more run
time than vibratory ones for the same result. Check out the web for
vibratory machines used by gun re loaders. They are much cheaper than
“Jewellery” tools, although usually smaller and not set up for flow
through. A good way to get an idea of what is possible with the
plastic media. And with a bit of plastic tube and a couple of buckets
a flow through system is possible. Plastic media is abrasive, good
for grinding down but it leaves a frosted finish. The rock rotary
will work with steel (stainless is easier) shot to get a ‘polished’
finish after the plastic. Larger diameter machines are faster. Big
flat areas do not finish well but for small details rotary works
well. There is a book in my library I can’t find at the moment which
was a great help when I had to set up a factory’s mass finishing
system, I believe it was written by Judy Hoch, good book and probably
updated since I used it.
Sarah; In some cases they are they same animal. I use the cheapie
from Rio it has lasted for years with an occasional belt replacement.
I use a plastic media then finish with stainless shot. For textured
surfaces it works great but not so much so for smooth surfaces.
Some people have recomended using steel shot in a rotary tumbler or
vibratory machine. I imagine that the steel shot would work harden
the silver a bit (this could be good in certain cases), how much
work hardening occurs though. Also, what are the chances the pieces
would get damaged from tumbling or vibrating with all that steel?
I’ve seen porcelain media available, is it any good?
Some people have recomended using steel shot in a rotary tumbler
or vibratory machine. I imagine that the steel shot would work
harden the silver a bit (this could be good in certain cases), how
much work hardening occurs though. Also, what are the chances the
pieces would get damaged from tumbling or vibrating with all that
steel? I've seen porcelain media available, is it any good?
I’ve been using a small vibratory tumbler with about 5 pounds of
assorted shapes of stainless steel shot for over 15 years. So far
I’ve not found any damage to anything metal or stone that went into
the tumbler.
If I were going to get a new tumbler, I’d get the same thing again.
I’d stay away from the rotary tumblers. 1st off they’re slower than
the vibratory, it takes a vibratory about 1/2 hour for a good finish,
longer won’t hurt, but isn’t necessary. 2nd, There’s no lid to leak
or belts to replace. They’re just a whole lot easier & more reliable
than rotary tumblers.
Metal does come out a little harder than it went in, but the change
in hardness isn’t that great.
The ceramic, I use to abrade with. Even in the finest forms, it has
never performed as well as the steel shot for me in polishing. I use
the vibratory machine for both materials.
If I were going to get a new tumbler, I'd get the same thing
again. I'd stay away from the rotary tumblers. 1st off they're
slower than the vibratory, it takes a vibratory about 1/2 hour for
a good finish, longer won't hurt, but isn't necessary. 2nd, There's
no lid to leak or belts to replace. They're just a whole lot easier
& more reliable than rotary tumblers.
I’d like to respectfully disagree with Dave Arens - when using
steel, there is no difference in the time between vibratory and
rotary machines. When using abrasive media, the vibratory is about
three times faster. I find that I get a very good finish with steel
in a rotary tumbler in thirty minutes.
Porcelain media comes in two flavors - abrasive and smooth for
polishing. Usually the abrasive media is little cylinders and has a
rating for what kind of finish you can achieve. This stuff is used
just like any other abrasive media.
The polishing media comes in little spheres. There are two very
important guidelines to polishing with it. First, you really need
more than one size of sphere. The second guideline is critical to
getting a good polish. The new media must be conditioned for a
substantial period. To condition porcelain spheres, load your closed
system vibratory tumbler with your polishing media, add five to ten
percent by volume of silver pieces. I typically use fused or cast
pieces. Add water and run for five days. Check periodically to make
sure that the tumbler hasn’t gone dry. I use about one fourth volume
of water of the tumbler capacity. For example if you have a five
quart tumbler, you need about a quart of water.
When your five days of conditioning is done, you will discover the
most wretched dirty mess. You will curse me. Separate the metal from
the media. Wash the media in soapy water. Use your ultrasonic on the
metal to get the gunk out of the crevices. The media will be kind of
grey and forever after will polish beautifully. It is substantially
cheaper than stainless steel and IMHO works far better than steel in
a vibratory tumbler. You certainly could condition with gold, but
silver works just fine for conditioning and it doesn’t matter what
metal you run after conditioning the media.
Vibratory and rotary tumblers both have a place in mass finishing.
I’ve had this particular rotary tumbler for 12 years, maybe more, and
it has worked flawlessly. It’s fairly large because I often tumble a
batch of anticclastic cuff bracelets in it. If you do big stuff, your
tumbler, whether rotary or vibratory, needs to have enough space for
your work to tumble freely.