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Post by petrifiedwoodaddict on May 26, 2016 11:52:43 GMT -5
How large of a stone can be tumbled?
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Post by Garage Rocker on May 26, 2016 13:13:10 GMT -5
Depends on the size of the tumbler. Let us know and I'm sure you'll get some opinions.
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Fossilman
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Member since January 2009
Posts: 20,711
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Post by Fossilman on May 26, 2016 17:03:12 GMT -5
My next project will be bigger stones... Listening with much interest!!
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meviva
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Member since July 2013
Posts: 1,474
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Post by meviva on May 26, 2016 17:49:45 GMT -5
I have never done it but I would think as long as it fits into the tumbler and has room to tumble it can be done. You would need to surround it with smaller rocks or ceramics to get it polished. Even if you had few larger rocks in the barrel you would still need the smaller ones to fill in the gaps. At least that's what I would do.
Andrea
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Sabre52
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Me and my gal, Rosie
Member since August 2005
Posts: 20,487
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Post by Sabre52 on May 26, 2016 19:55:22 GMT -5
Andrea has it right. I've done 4-6 oz stones in my 12 pound barrels and finished them in my ten pound vibe rig. Best to use only a few big'uns with lots of smaller stuff because otherwise, the large stones will knock together and get little micro fractures. The small stones also favor better surface to surface contact so you get a better finish on the large tumbles....Mel
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jamesp
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Member since October 2012
Posts: 36,562
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Post by jamesp on May 27, 2016 7:13:22 GMT -5
Andrea has it right. I've done 4-6 oz stones in my 12 pound barrels and finished them in my ten pound vibe rig. Best to use only a few big'uns with lots of smaller stuff because otherwise, the large stones will knock together and get little micro fractures. The small stones also favor better surface to surface contact so you get a better finish on the large tumbles....Mel Tumbling larger rocks together in a rotary has been the challenge for me. I have a 30 RPM and a 55 RPM coarse grind arrangement both with 6 inch diameter barrels. Run clear crystalline quartz say 4-5 ounces with a good mixed load and you WILL have frosted edges at 55 RPM.(my experience). Run them anyway at 55 to shape them. Then put them in the 30 RPM with good mixed load at 75-80% fill and thick slurry to grind off the frosting. agate on the other hand can be shaped at 55 RPM. It is a function of the rock structure when tumbling big rocks. The hardness and toughness of the rocks you are tumbling that comes into play when running large rocks together. As does the speed of barrel+diameter of barrel+thickness of slurry+mix of sizes+fullness of the barrel. The vibe works fine if you do what you and Andrea mention. 6-7 ten ounce stones, say 4 pounds total, with 10 pounds of pea sized media is best I can do with a 14 pound vibe. For coarse grinding 10 rocks 8-12 ounces in 15 pound 6 inch diameter barrel: 30 rpm maximum barrel 75-80% full agate, pet wood, jasper an equal blend of rock sizes from 3/4" to 2" surrounding the 10 large rocks thickish slurry best I have used the above recipe quite a few times and never had the slightest bruise on the most pointed edges of the big rocks. Excellent prep for the vibe. Finishing big rocks in a rotary is real tricky. Unless you have only one big rock, then it is easy. The #1 problem with big rocks is them banging against each other in a rotary. 10 ounce tumbles are a trophy. Only for a safe deposit box.
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Post by parfive on May 27, 2016 12:16:21 GMT -5
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jamesp
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Member since October 2012
Posts: 36,562
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Post by jamesp on May 27, 2016 14:18:25 GMT -5
Gotta see this tumble, wow.
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grayfingers
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Post by grayfingers on May 27, 2016 14:54:16 GMT -5
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jamesp
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Member since October 2012
Posts: 36,562
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Post by jamesp on May 27, 2016 17:48:41 GMT -5
Nice work grayfingers, no bruises on the sharper edges.
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Post by petrifiedwoodaddict on May 27, 2016 19:06:13 GMT -5
Can only see the first picture of that stone, would love to see how it turned out.
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meviva
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Member since July 2013
Posts: 1,474
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Post by meviva on May 27, 2016 19:23:56 GMT -5
Can only see the first picture of that stone, would love to see how it turned out. The finished stone is on page 2 of the thread.
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jamesp
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Member since October 2012
Posts: 36,562
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Post by jamesp on May 27, 2016 19:39:38 GMT -5
These rolled together, then finished in vibe last week. 14,10,10,9 ounces in vibe, 4 pounds big rocks, 10 pounds small media Coral, looks like this before tumbling The orange/brown coral
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