Hi Kai-Ti, A vibratory tumbler is generally more versatile than a
rotary tumbler, in that the vibratory can run a variety of different
medias for both cutting and polishing (such as ceramic and plastic
abrasives, walnut shells for polishing, steel shot, etc.). It can
run all these medias effectively and in a reasonable time frame.
This is because the entire tub of media tumbles (or vibrates) so
that all the media is acting on all the parts all the time.
On the other hand rotary (or barrel) tumblers work by turning a mass
of media and parts around and around in a barrel. Basically, the
action occurs only in the top layer of media as it slides down with
each turn of the barrel. Still, in my opinion, a rotary is the best
tumbler for running steel shot. The weight of the shot combined
with the rotary motion makes for great burnishing especially of
silver (and it also work hardens the surface of the jewelry).
Rotary tumbling is not as effective for lightweight medias such as
walnut shells. Walnut shells might take 16-24 hours (overnight) to
achieve a high polish in a vibratory tumbler, but more than twice
that long in a rotary tumbler to get the same finish.
(Disc finishers, by the way, offer the same versatility in terms of
media types as the vibratory tumbler but disc finishers have MUCH
faster processing times. They’re great for production and when time
is a factor in your finishing. Magnetic tumblers are also fast but
they are specifically designed to run one type of media (tiny steel
shot pins) for getting into highly detailed areas or undercuts or
into settings. In fact, all the areas that are difficult to polish
by hand, magnetic tumblers can polish to a high shine and very
So if you looking to do some cut-down steps as well as polish, you
probably want to look at Vibratory Tumblers (or Disc Finishers). If
you’re looking only to polish, then a Rotary Tumbler is a good
The size of your parts (and the number you want to run at one time)
determine the size of the tumbler you choose. The tumbler bowl or
barrel has to be big enough to let the part tumble around freely in
it – so, for a cup, you’d need a pretty large tumbler! A rotary
tumbler might be the best bet for something this large since a
relatively small unit could accommodate one cup. However if you want
to tumble several cups at once, you’ll need a very large barrel.
The idea is you don’t want to have too many parts in the tumbler or
they will bump into and scratch each other defeating the purpose of
Generally speaking about a 10 to 1 ratio of media to parts by volume
is desirable. However that ratio will vary somewhat depending on the
media you use.
Steel shot is a great media for burnishing sterling and silver but
many many people like it for gold and other yellow metals.
Personally I prefer walnut shells (treated with red rouge) for
polishing gold and yellow metals. I think it gives a warmer finish
– but that’s just my personal opinion.
Many suppliers will run samples for you at no charge. You might
want to check that out prior to purchasing a tumbler – it can save
you a lot of time and experimentation as well as money.
I hope this has been of help.
Gesswein Co. Inc. USA
Bridgeport CT 06605
Tel: 1-800-544-2043 x287