Unusual examples of tumbling?

[Stephen Tashiro]

I've read that people who make jewelery have small tumblers that they fill with rocks and abrasives. They leave these small machines turning for hours and the rocks get polished very smooth.

I've seen a cement mixer that got very clean after it was run for a few hours with some pieces of 2x4 and pecan shells in it. (The sound of the machine running was rather loud.)

Are there any other interesting examples of tumbling being used to polish or grind up material? I'd like have some sort of small machine that would pulverize old pieces of concrete and concrete block into particles that could be re-mixed into crude concrete construction like concrete poured around fence posts. (However, I don't know if I'd want to listen to such a machine for hours and hours.)

[Eric DeSilva]

I use a Lortone tumbler for polishing silver jewelry. It looks a bit like a rock tumbler, but it is filled with little stainless steel pins. Clean post-soldering junk off silver like no one's business tho'.

However, I would think tumbling would be a rather inefficient (as well as loud) means of making concrete into powder.

[Brian Elfert]

I would think you would be better off going to a local place that recycles old concrete than trying to build your own.

[Belinda Barfield]

This machine works for all types of natural stone, and may work for concrete. It's used for crushing stone for recycling.

https://ecom.granquartz.com/VIA9/viaUserDoc.jsp?searchText=0831&secondPass=0

[David G Baker]

Stephen,
I don't think it would be cost effective to tumble concrete to turn it into powder on a small scale. The energy consumed would more than likely cost a lot more than purchasing new concrete for your personal consumption. Many concrete suppliers do have pulverized concrete on hand and sell it at a reasonable price.
I used crushed concrete on pads where I park my farm equipment. The crushed concrete keeps the water and mud away from the base of the equipment.

[Horton Brasses]

Tumbling is widely used in many industrial settings. The machines and media run a huge gamut. A rotary tumbler might be good for concrete-with something like steel shot for a media, but I really don't know.

We use cob in vibratory tumblers for drying and cleaning, various sizes of porcelain stone (in different vibratory tumblers-some with soap and water, some without) for surface finishing, and walnut shell for fine surface finishing.

Your best bet would be to call a company that does abrasives and see what they say about your specific applications. there should be someon in your local yellow pages, but if not we use these guys for most of tumbling supplies: www.acaabrasives.com -they are reasonably knowledgeable and have helped us find some solutions over the years.

[Russ Filtz]

I'd like have some sort of small machine that would pulverize old pieces of concrete and concrete block into particles that could be re-mixed into crude concrete construction like concrete poured around fence posts. (However, I don't know if I'd want to listen to such a machine for hours and hours.)

Are you talking about trying to crush concrete into powder and REUSE it as new concrete mix? Won't work. The cured concrete has gone through a chemical reaction (hydration). You would need to re-kiln this powder to re-calcinate the cement.

http://matse1.mse.uiuc.edu/concrete/5.gif

Crushed concrete can be utilized for other things, such as general fill or base material for roads, etc. Best to keep it out of groundwater though as things can get leached out and turn it spongy (I'm guessing any limestone aggregate).

[Stephen Tashiro]

My thought would be to used the fragments of old concrete blocks in the same way that one uses aggregate. So I would be using new cement and sand in the mixture. Concrete fragments wouldn't be as strong as typical gravel but I think it would be adequate to anchor a small fence post. And it would help me get rid of the old concrete blocks in my backyard!

[Leigh Costello]

Totally unrelated stonework-wise, but when I used to help out on the neighbor's dairy/pig farm, we tumbled the corn to shell it, ground the corn or cracked it, and then ground the cobs to add to other feeds. We used old water heater tanks that were rigged up with welded baffles, hooked up the pto and clatter clatter thump clatter and out came the shelled corn. Noisy but very effective. Thinking about it now just makes my head ache!

[John Coloccia]

Here's some unusual tumbling
http://www.youtube.com/watch?v=TipiCj90Wb4&feature=related