Your textured jewelry that I saw on the web would work well with
mass finishing. What you have discovered is that tumbling doesn't
just mean dump stuff in a jiggly box and get nice results.
First, the tumbler you have is intended for rock tumbling. The
instructions for rock polishing include having four pounds of rocks
and water and abrasive in the machine. So the first clue is that you
need 4 pounds of stuff. Second, the media needs to turn, not just
jiggle. The problem with using steel in a rock tumbler is that the
steel is so dense that the vibration of the tumbler won't make the
This answer probably won't make you happy - but you need equipment
that will work for jewelry. Your jewelry needs to move freely inside
the tumbler, and the media in the tumbler needs to roll. I just
tested a similar tumbler for finishing and it was unsatisfactory for
steel or abrasive media. It did work with dry media for tarnish
I've written a small book on the subject - Tumble Finishing for
Handmade Jewelry" Most of the Orchid sponsors sell it. It would save
you boatloads of learning time.
And a magnetic tumbler is a very poor choice for your heavy jewelry.
It works best on quite small pieces. I've created massive trash with
a magnetic tumbler when trying to finish sterling silver with fine
silver bezels. I use a magnetic tumbler to finish hand made ear wires
and very small fiddly items.
Lots to learn - but I wouldn't trade my tumbler collection for three
studio assistants. If you use the machines properly, you don't lose
detail and you get consistent results.