I bought 200 lbs of little beads, 2nd hand, thinking they might be porcelain media. Media in this sense are masses of small, hard, identical pieces used in tumbling or vibratory finishing of metals. Porcelain beads are the preferred hard media for vibratory finishing of brass. Our vib finishing machine is a "Mr. Deburr" that needs over 100 lbs. of hard media to cycle correctly, and at say $5 a pound, retail porcelain has always been too costly. That's why I'm hoping these off-white, dull (matte appearance) 4mm diameter balls are porcelain, not ceramic or other material. The seller was not original owner and had no idea beyond "media." Anyone know? Would a photo help?
I'm not into metal tumbling but I do use media in my large rock tumbler; so what I'd say is porcelain media works better when it is smooth. Something I'd try is tumbling fine silica carbide grit with the media, you might be able to polish the porcelain.
I'm not really familiar with what these should look like other than what shows on Google. Maybe a photo would help someone, I'm assuming they have no holes. If it helps I can give you a little test we'd use in archaeology. So, ceramic is a broad term covering things made of clay. Porcelain is a type of ceramic made of particular types of clay that can be fired at extremely high temperature that sort of fuses the material making it mostly impervious to water. Earthenware types are fired at lower temps and are more porous. (And of course lots of in-betweens) Anyway, if you touch the unglazed part of a piece of porcelain to your tongue it shouldn't "stick". If you touch an unglazed part of earthenware to your tongue it will "stick", in that you can feel the suction. Don't know if that helps or not.
Thanks, did that tongue test and boy are they bitter tasting! Really reeked of almond smell too! Well I'll take that picture after I find out why I'm getting lightheaded and my hands are turning black. Uhhhoooo...
I hope you washed them. If they were used in a tumbler it could be very harmful to ingest or inhale any of the powder from stone or metal. http://sciencing.com/harmful-effects-powdered-mica-8551607.html
Jes' kiddin! And they didn't pass the porcelain tongue test, I'd have to say they were a bit on the "sticky" side, but a little hard to tell with something that small.
There must be data out there on tumbling media. If you can find a rated hardness for porcelain media and test yours against it, that might be the easiest test. Mass would be another indicator. ******* from Wikipedia: On the Mohs scale, a streak plate (unglazed porcelain) has a hardness of 7.0.
Spring -- WHY do I always read your entries?!! Perhaps I thought you had taken up jewelry-making...? However, this time, although I was not aware of the meaning of "media" in this context, I actually did know what you were talking about. Love the Agatha Christie touch!
Thanks for info; good ideas on the physics-based testing, I can look up hardness of some common stuff and see if the spheres scratch it, I'm as always looking for the quickest easy answer. I could peruse porcelain-bead vendors and see if any even offer them in 4mm, I didn't notice any last trip there but wasn't focused on that. For all I know the 4mm's could have been the beads-de-jour when these were first sold perhaps decades ago.
Turns out 4mm are still sold, but looking at this pic of 5mm real porcelain beads, they are smoother and shinier than mine.
WHAP! That's the sound of today's forehead-slap, triggered by the realization that my investigation of this "media" contained a giant gap, to wit, my failure to thoroughly inspect the 55-gal. Drum containing this stuff. The steel covers of these things are usually secured with a circular band tightened by a bolt, after struggling with that the day I got it, I set the cover aside, upside-down. Today I went to replace the cover and finally noticed the very- faded label "used desiccant." Used desiccant is completely worthless unless it is the Rechargeable type, and as to that IHNI. It sure isn't "media" I can use for vibratory cleaning though. So all I can say is "Duh" and some other things I don't want to post here. I'll see if the Vendor will refund and let me dump the stuff locally-normally they require return but the cost to ship it back might exceed the refund, anyway I'm not too concerned either way, I took a risk in buying it and lost; life goes on!
What the label says and what's in the drum aren't necessarily one and the same thing. Are you convinced that it is desiccant?
. Yes unfortunately, crushes as easily as spherical cereal pieces I can't name-Kix, Trix? Solid polishing media is stone-hard and harder. Will see if it can be recharged and if not, it goes. Dealer gave me $50. Store credit which I accepted. We have enough ceramic media to last a couple years in our vibratory cleaner, and we'll just continue to use the rotary tumbler with crushed walnut shells and liquid polish for cleaning brass cartridge cases. I'd pay $1 a pound for bulk porcelain beads, but not the $3 plus everyone seems to want.
