jamesp
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Post by jamesp on Jun 21, 2016 6:13:12 GMT -5
I intentionally pulled some stones out of the rotary early with fresh SiC 30 finish. Ran them in the vibe with (cheap sand blasting)Aluminum Oxide 80 from that afternoon to next morning(18 hours). Rocks had what looked to be an AO 1000 polish, maybe better. This ~1000 finish did not improve after 48 and 72 hours in the vibe. Next step is Rock Shed AO 14,000 polish for 24 hours. New recipe SiC 30 grit 8-12 weeks adding fresh SiC every 3 days in rotary at 30 RPM, 6 inch barrel, clay thickened slurry. Well rounded rocks. Aluminum oxide 80 for 24 hours 1 cup sugar/1 cup water for 14 pounds of rock in vibe Aluminum oxide 14,000 for 24 hours with damp Borax for 24 hours in vibe. Coral after 18 hours in AO 80 in vibe. a pre polish at this level about always ends up with a wet shine after 24 hours using polish w/Borax:
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jamesp
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Post by jamesp on Jun 21, 2016 6:38:56 GMT -5
The biggest grit that I could find is 3.5. It averages .22 inches across. Say 5mm. 30 grit is basically 1/10 that size at .022 inches. 80 grit is .007 inches, about 1/3 the size of 30 grit. Guessing that even 5 mm aluminum oxide will not break down but form a polished bead in a vibe and impart a fine pre polish in a day or two. It would end up being 4mm ceramic media is my guess after wearing smooth. Being that most of our ceramic media is basically giant aluminum oxide grit particles. On the other hand, 5mm SiC/3,5 grit would do what it is designed to do, shatter into smaller very sharp particles. Source(Washington Mills is the manufacturer of most of our tumbling abrasives): www.washingtonmills.com/guides/grit-sizes-ansi/particle-size-conversion-chart-ansi/P.S. ASTM Sieve = grit size
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jamesp
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Post by jamesp on Jun 21, 2016 6:47:15 GMT -5
The stupid alternative was doing what I was doing; run the last 30 grit run for two weeks in the rotary to break down the SiC 30 to about 500 grit. Then go to AO 500 in the vibe for 3 days.
Using the AO 80 in the vibe cut 10-12 days off of that process. But added a day in polish with Borax.
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Post by Garage Rocker on Jun 21, 2016 7:27:33 GMT -5
I like your spirit of experimentation. Interesting results.
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jamesp
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Post by jamesp on Jun 21, 2016 7:41:01 GMT -5
I like your spirit of experimentation. Interesting results. That was an easy one garage. Just happened to have some old AO 80 from way back to try. I was really trying to remove some bruises on some delicate quartz from the rotary. Knowing AO, that it does not break down as much as rounds and polishes, results not surprising other that the speed at which it rounded and polished. A consideration for those with vibratory barrel wear issues. Yes, it is 80 grit but only for a very short period was it sharp. I think SiC 120/220 SiC 220 SiC 500 wears vibe bowls out a crap load faster due to 1-4 day runs and the razor sharp particles.
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napoleonrags
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Post by napoleonrags on Jun 21, 2016 9:20:14 GMT -5
I like your spirit of experimentation. Interesting results. Agreed.
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jamesp
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Post by jamesp on Jun 21, 2016 9:25:24 GMT -5
Saga continues. Playing AO Devil's Advocate. Would have shaved 3 days off of 5 days doing AO 80 for 1 day and AO 14,000 for 1 day. 4th day in vibe with AO 80. Dang near a wet shine. A plain 1 day Borax burnish would get er done. day 4, AO 80 A big thanks to Mrs. Jean rockpickerforever for the 4 pound block of gem palm of which was reduced with the greatest of care. Just like a soft shell turtle, had 7 different meats. Wish we could find such in 100# qty's. Stone cold shiny: And a slice of Florida redneck coral. Has a clear corona at very edge, thin white layer, thick black layer, and then the yellow guts
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jamesp
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Post by jamesp on Jun 21, 2016 9:32:02 GMT -5
I like your spirit of experimentation. Interesting results. Agreed. Selfish motives also. Trying to find shortest point A to B. Remember your dating career lol ?
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napoleonrags
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Post by napoleonrags on Jun 21, 2016 9:33:53 GMT -5
That was an easy one garage. Just happened to have some old AO 80 from way back to try. I was really trying to remove some bruises on some delicate quartz from the rotary. Knowing AO, that it does not break down as much as rounds and polishes, results not surprising other that the speed at which it rounded and polished. A consideration for those with vibratory barrel wear issues. Yes, it is 80 grit but only for a very short period was it sharp. I think SiC 120/220 SiC 220 SiC 500 wears vibe bowls out a crap load faster due to 1-4 day runs and the razor sharp particles. A few things: We use what we have. I stopped using 500 grit because I ran out. I have probably 5 pounds of 220 SIC, so I'll use it until it's gone. I've been running one Lot-O bowl for over a year with 220. It will be interesting to see how long it lasts. How did the quart turn out in comparison? So, now you no longer do the two-step? It's more of a waltz...that should be softer on that delicate, Southern Belle, quartz. Keep on waltzin' and rollin' Colin
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napoleonrags
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Post by napoleonrags on Jun 21, 2016 9:39:02 GMT -5
Selfish motives also. Trying to find shortest point A to B. Remember your dating career lol ? Well said.
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Post by captbob on Jun 21, 2016 9:53:56 GMT -5
Fresh 30 grit every 3 days?! What do you figure it's broken down to in 3 days?
Wondering (thinking) that your hard PVC barrel is a huge aid in breaking down such a coarse grit quickly. Wondering (doubting) that it would break down so fast in a rubber or rubber lined barrel.
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jamesp
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Post by jamesp on Jun 21, 2016 10:34:53 GMT -5
Fresh 30 grit every 3 days?! What do you figure it's broken down to in 3 days? Wondering (thinking) that your hard PVC barrel is a huge aid in breaking down such a coarse grit quickly. Wondering (doubting) that it would break down so fast in a rubber or rubber lined barrel. Same thing in the 12 Lortone Bob. 30 gone in 2 days. 3rd day just to make sure. No doubts. the 30 grit looks like giant salt particles, easy to see. Unlike 80. 30 grit after 8 hours @ 30 RPM in 6 inch PVC. Separated in water on vibe. One cup SiC 30 I carefully scavenged the grit after 8 hours. Or the white plate display, same, after 8 hours(left), virgin on right.
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jamesp
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Post by jamesp on Jun 21, 2016 10:39:35 GMT -5
Folly to run SiC 80. Folly to run SiC coarse longer than 3 days without adding more.
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Post by captbob on Jun 21, 2016 10:47:50 GMT -5
Very interesting James. I got a 50 lb LFRB of 30 from Kingsley a couple weeks back. They actually got the entire 50 lbs in said box! Never used 30 grit before, bought and looking forward to trying based on your experiences using such.
Now, I just need to find the time to play with rocks! Maybe next month...
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jamesp
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Post by jamesp on Jun 21, 2016 10:51:20 GMT -5
You will be surprised captbob at how fast that SiC gets smashed to nothing. Reopening every 3 days sucks. But rocks get rounded quick.
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Post by captbob on Jun 21, 2016 10:58:19 GMT -5
Gonna make me one of them super grinders with like 8 (whatever) ganged saw blades before I get the tumblers rolling again. Have plenty of machines sitting around that I can use for such, again need to make the time. Very high on my list though. Figure having/using one will take months off the coarse grit run.
back to it...
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herchenx
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Post by herchenx on Jun 21, 2016 12:21:02 GMT -5
Man, Jim you nailed those, awesome!
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Post by rockpickerforever on Jun 21, 2016 15:55:15 GMT -5
James, I know that it is just a reflection of the overhead light, but this one looks like a mussel on the half-shell. with a giant, mutant pearl inside, lol. More pics, please. I know you had more than one. It was some nice material, will always be on the lookout for more of it. Will have to be from estate sales and such, probably not a lot of it left in the wilds.
You did a super nice job of it. I know, it took forever.
I have some hard stones in the Scott-Murray tumbler right now. For the first time, I am also following this (30 grit added every third day or so) recipe. Some days, I did not add, if I felt the grit was still sharp and doing its job (grinding rocks!). I did actually let it go for about a week, and the grit was broken down to I'd say at least 220, maybe finer. But since the rocks need more grinding/shaping, I added back some of the slurry (with sharp grit) that I had removed earlier.
When I feel the rocks have been rounded enough, I will let it go a good week without opening the barrel, as I can see that any still sharp/coarse grit stuck around the lid will scratch everything up should it get dislodged. (It is a 15 lb hex barrel, like the Thumlers B model.) Started this run exactly a month ago, have not done a full cleanout yet. Only adjustments to slurry, addition of grit.
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jamesp
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Post by jamesp on Jun 21, 2016 19:06:34 GMT -5
Gonna make me one of them super grinders with like 8 (whatever) ganged saw blades before I get the tumblers rolling again. Have plenty of machines sitting around that I can use for such, again need to make the time. Very high on my list though. Figure having/using one will take months off the coarse grit run. back to it... I remember a mandrel you had. Guessing that will be your ganged blade machine. I think you will like to have the fast grinding action. Must say that the few times I spent a bit of time making shapes for the tumbler were rewarding. grind so much metal that I am short on patience grinding rock shapes.
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jamesp
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Post by jamesp on Jun 21, 2016 19:14:47 GMT -5
rockpickerforever, those are just a few I grabbed before the were sent to final polish w/Borax. I will be doing detailed photos on that palm. Palm like that is just not easy to find. Sounds like you got a system going with the ScottMurray. That last run- take the cap off and wash all trapped grit out of the corners a few days into it. should get rid of the big particles that could scratch. One time I had some scratches. Rarely though. Grind away Jean. You started with the sophisticated cab work and coming down the ladder to tumbling. Liking the imagination. Quahog clams have purple pearls.
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