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Post by HankRocks on Oct 24, 2017 18:15:37 GMT -5
Does anyone have an idea of the breakdown rate for AO? I realize it is dependent on the type and shape of rocks being tumbled. Thanks
Henry
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Post by Garage Rocker on Oct 24, 2017 18:56:10 GMT -5
Nah, James, I know you're trying to figure out how to use that aggressive machine you've got with delicate material. The Lot O wouldn't be fun for a mad scientist, anyway. The work you're doing may well just teach us all how to get a shine on soft rocks that are still problematic. Yep, and the experiments are a hobby. I bought three little tubs for the Vibrasonic. Same tubs that fit on the Mini-Sonic. Must fabricate a conversion mount. That way I can run 3 experiments at a time. Sounds like some fabrication fun. Look forward to seeing it.
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jamesp
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Post by jamesp on Oct 25, 2017 5:40:03 GMT -5
Yep, and the experiments are a hobby. I bought three little tubs for the Vibrasonic. Same tubs that fit on the Mini-Sonic. Must fabricate a conversion mount. That way I can run 3 experiments at a time. Sounds like some fabrication fun. Look forward to seeing it. Thanks Randy. It would be copying an already made $200 bracket that is on the market. Nothing newly invented. Now a 5000 to 6000 vibration per minute vibratory tumbler would be new and gnarly. Just to perform tumbling operations in it would be a rush. Would you ever consider a hot rod tumbler ? Hey, they have riding lawn mowers that do 60 MPH. Unfortunately no production model would ever be made to run that speed because of the production company's product liability. And their good engineers can not take a swing at it and do a good job on it. So a project for a shade tree guy.
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jamesp
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Post by jamesp on Oct 25, 2017 5:56:53 GMT -5
Does anyone have an idea of the breakdown rate for AO? I realize it is dependent on the type and shape of rocks being tumbled. Thanks Henry Aluminum oxide and Sic and most other tumbling abrasives are ceramics. Garnet is a naturally occurring material that usually has 25% AO in it. Many tumbling medias are made out of 97+% aluminum oxide. So slow to wear. Answer is AO is slow. But it depends how it is made too. Fused for instance. Made in many forms. I just call mine Rock Shed AO if bought there. It seems consistently used here. I've used 3 different colored AO 80's. Not sure how different they are from each other but they all 3 do the job the same. SiC is harder than AO but way more brittle. In most cases it breaks down faster. So hardness and toughness are 2 different properties to consider. Consider a softer Mohs 6 abrasive pumice is friable because it is porous. Much easier to break down. Diamond may not break at all in a tumbler. Good for coarse grind. Terrible for making a finish.
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Post by grumpybill on Oct 25, 2017 6:35:49 GMT -5
When I saw this chart last night, I was surprised to see the difference between Alumina and Aluminum Oxide. linkThis might explain why my last batch didn't polish well. I used some powder labeled "Alumina - Polish" that had come with one of the used tumblers I'd bought.
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Post by HankRocks on Oct 25, 2017 6:39:17 GMT -5
Was just curious how far the 80 AO would break down in 8 to 10 days. After 7 days there was a dull shine on a batch of mostly preforms which seem to always take longer to reach polish because of the flat surfaces.
Was going to re-visit Obsidian and Apache Tears and use the Rotary instead of the UV-18 which seems a bit to violent, for the final Polish. A 80% filled rotary with a thick polish slurry might be better for me. Will also try to buy a mini-sonic double 4 pounder from a old friend. Seems like I read somewhere that the mini-sonic was a bit gentler than the UV-18. Will probably not start this for a month or so am following your tests with some interests.
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jamesp
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Post by jamesp on Oct 25, 2017 10:16:36 GMT -5
Was just curious how far the 80 AO would break down in 8 to 10 days. After 7 days there was a dull shine on a batch of mostly preforms which seem to always take longer to reach polish because of the flat surfaces. Was going to re-visit Obsidian and Apache Tears and use the Rotary instead of the UV-18 which seems a bit to violent, for the final Polish. A 80% filled rotary with a thick polish slurry might be better for me. Will also try to buy a mini-sonic double 4 pounder from a old friend. Seems like I read somewhere that the mini-sonic was a bit gentler than the UV-18. Will probably not start this for a month or so am following your tests with some interests. In my Vibrasonic AO 80 is darn near polish in 2 days. I only use 2 tablespoons for 14 pounds of rock and 2 tablespoons of Borax. 2 days running Mohs 7 rocks. If you were running Mohs 3 rocks then it would take a very long time to break down the AO 80. No matter how violent your vibe. Yea, the point I wanted to make was that all vibes are not created equal Henry. To make folks aware that the Lot-O is a fine machine for sensitive rocks. But by the same token, it may take say 4 to 6 days to break down AO 80 running Mohs 7 rocks. And seems to be the case. Lot of the older vibes were really designed for hard agates. Where to go from there ? I just gave up on soft and did Mohs 7. Slurry may be the best solution for these old vibes to run soft rocks. And yes, the final polish is when you find bruises and frost in most cases. Darn, too late then.
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jamesp
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Post by jamesp on Oct 25, 2017 10:25:41 GMT -5
When I saw this chart last night, I was surprised to see the difference between Alumina and Aluminum Oxide. linkThis might explain why my last batch didn't polish well. I used some powder labeled "Alumina - Polish" that had come with one of the used tumblers I'd bought. What is tricky about Mr. Mohs is it is only a scratch test. Felspar has a structure that will scratch. But it is made up of a lot of hard particles. Plowing thru the particles with a sharp object is easy. But looking at it on a particle level is very different. Similar to scratching a ball of aluminum oxide glued together with Elmer's glue. Alumina polish, have not looked at that one Bill. I like the hardness chart. Lots of abrasives listed. Why alumina is Mohs 3 is a mystery. Must research that one.
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