I’ve seen so many questions about this technique on the Internet that I had to share what I’ve learned from my experiments.
I prefer vibratory tumblers to rolling tumblers because they’re quieter and work more quickly. Plus, they are less likely to distort the shape of the beads. When my beloved Vibratech tumbler (no longer made) gave out earlier this year, I researched vibratory tumblers and liked what I read about the Raytech brand. You can read more about Raytech tumblers here.
As you probably know, vibratory tumblers can be expensive, but Raytech makes a hobby-sized model that won’t break the bank. I chose the Raytech TV-5 Complete Vibratory Tumbler Kit from erocktumbling.com because they had the best price and it comes with a spare bowl and bolt.
I tumble my baked beads with Bon Ami cleanser and water. I got the idea from a post on Glass Attic. I don’t just finish my beads this way; this is the only sanding they get. Of course, if you have a real bumpy bead, you probably need to whip out the sandpaper, but I’ve found that the Bon Ami tumbling method works on hand-formed beads, extruded beads, beads made with bead rollers and it puts a nice finish on most shapes, including disc and lentil, and carved faux beads. I always drill after I tumble.
I wait until I have a bowlful of beads and I put them in the container (which looks like a bunt pan) with about half a can of the cleanser. I pour in enough water to make a slip-like substance that coats the beads. What smooths the beads is the abrasive action of the Bon Ami and the beads vibrating (rolling actually) into one another. If you have too much water, there’s not enough abrasive action. Too little water, and the beads become embedded in cleanser muck and won’t move.
The Raytech TV-5 is low tech. You turn it on and off by plugging and unplugging it. I sit mine on a cement floor in the basement. It has a clear plastic top that screws on with a rubber and metal bolt. It’s important to screw the bolt on tightly for two reasons: First, the tighter it is, the quieter the tumbler runs. Secondly, the water will evaporate more slowly allowing you to leave the tumbler on for 12-24 hours at a stretch.
I check my beads every 12 hours or so, unplugging the tumbler first, taking out a bead, rinsing all the cleanser off, feeling the surface and noting the shape. If I decide to continue tumbling, I might add water if the bowl contents are too dry or a bit more cleanser if the bowl contents are too wet.
Whether the beads get another tumble depends on how smooth they are. There is no exact recipe; each batch is different and things like bead shape and humidity (which affects how fast the water will evaporate) influence the process. You have to experiment and see what works for you.
When the beads are as smooth as I like, I dump the contents of the bowl into a dishpan filled with water and dislodge as much of the cleanser as I can. Then I put the beads in a big mesh strainer and rinse off more cleanser. I put them back in the bowl (which I have cleaned) and tumble them for a day in water and a few drops of dishwashing liquid. The cleanser will get into small cracks (usually in faux beads) and this process removes most of it. Sometimes I finish cleaning any cracks with a toothbrush, but I’m not obsessive about it. This is supposed to be a work saving technique after all.
It is very important to dry the beads and get as much of the white haze off of them as you reasonably can before buffing. I buff the beads with a high-speed buffer and a muslin wheel. The result is the nice shiny finish.
The left picture shows an experiment: untumbled baked beads (front) and other shapes made from the same clay that were tumbled and polished on a high-speed buffer. The beads on the right were tumbled and buffed.
Why use Bon Ami instead of tumbling grit? You can pour your waste water down the drain for one thing. And the grit is made for stones. The Bon Ami might take longer, but you won’t have to check as often and you are less likely to ruin your beads. If you have any doubts about the capability of Bon Ami cleanser and water to remove baked clay from beads, look at the picture below. The two beads were identical and the one on the right spent a few days in the tumbler.