Robert - skipping the smoothing part will result in icky results
from the steel.
First you run your shaped bracelets in abrasive media, like you have
before. Then clean then well and run with burnishing compound and
steel for up to an hour.
Running them flat will have then nest in the steel, abrade each
other and generally get in the way of good finish. Running longer
than an hour will degrade the finish. Trying to harden them in the
shot only affects a micron layer of the surface. As you shape the
bracelets, prior to any tumbling, work harden them then.
A rock tumbler is ok for using shot - but: be sure the inside of the
barrel has “flats” not just round inside. Check the quality of the
rubber. What ever size of barrel, it should be filled at least 40%
with shot and your work. If you try to run too much work, it will
impinge on each other. The bracelets need to be able to move freely
inside the barrel.
The good news, the shot doesn’t wear out. Yes the abrasive wears
down, but it is sure cheaper than hand working the pieces.
I have finished literally hundreds of bracelets in my tumblers this
way, with sparkling results.
And - you might want to look at a newer model of rotary tumbler -
the acrylic barrels are much easier to close and open, don’t leak and
let you see what’s happening. This is the model I use -
Note that it requires a minimum of 5 pounds of shot and will run up
to 12 pounds of shot. Similar machines are available from most
jewelry supply houses. I especially like the variable speed and the
option to reverse direction automatically during the run.
Judy Hoch, G.G.