jamesp
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Post by jamesp on Dec 1, 2014 7:50:48 GMT -5
The rotary experiments frosted the larger pieces of obsidian. So I have 7 pounds of it in the vibe with AO 220 grit. With 7 pounds of glass filler. After 2 days the 220 was pulverized to cream, so I added more 220 with out cleaning out. The new 220 particles were obvious, like spots in the cream of the old 220 slurry.
The first 220 run did not remove enough material to remove the frost damage(mostly on the edges). But seemed to have removed the shallower frost damage. Guessing that the second addition of 220 will not remove all the frost damage either.
So to remedy the frost damage on the remaining 18 pounds of obsidian I am running them in the 30 pound rotary barrel. 18 pounds of obsidian, 12 pounds glass filler, AO 46 grit, and at slow 12 RPM, barrel 7/8 full. (The prior runs in the rotary with 46 and 220 never frosted with the 35-40% glass media) From there to the vibe w/AO 220 and 50% glass media. And vibe to hopefully final polish.
Conclusions-1) frost damage is deep, and requires a coarse grit run to remove it. 2) when people suggest media for obsidian, listen 3) consider a vibratory tumbler for this finicky PITA rock 4) Be prepared to eat humble pie for deviating from tried and tested ways and machines Thank you connrock, captbob, Drummond Island Rocks, tk and a few others for the hints, suggestions and 'I told you so's'
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Post by connrock on Dec 2, 2014 8:17:08 GMT -5
I would think that the 46 grit should be run for 2 weeks to let the grit break down cuz 46 grit will leave a pretty rough finish on obsidian??? Good luck,,, connrock
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jamesp
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Post by jamesp on Dec 2, 2014 8:45:33 GMT -5
I would think that the 46 grit should be run for 2 weeks to let the grit break down cuz 46 grit will leave a pretty rough finish on obsidian??? Good luck,,, connrock yep. If only 120 was in the cupboard. If the vibe was empty I would have run them in 46 and smashed that 46 quick !! It was a big load @ 18 pounds so I chunked them in the rotary. 2 weeks sounds right to me too. Plus I am a loser at polishing obsidian. I better master a load polished in the vibe first ha. The load of obsidian in the vibe is cranking along at beat down 220 right now. Please do a polish dance for me connrock. The poor batch of obsidian probably wants a dance too. Check out the tumbler i am building in home made. Thinking about lining it with diamond. opinions
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Post by broseph82 on Dec 2, 2014 9:08:17 GMT -5
I'm going to treat my slag glass as obsidian in my rotary so keeps us updated. I'm absorbing as much info and trials of just about everyone here
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Post by captbob on Dec 2, 2014 9:25:10 GMT -5
<------ Polish Dance Why do you have 220 in AO instead of SiC ? I think I recall your 500 being AO as well? You go from 46 SiC to 220 AO in every batch? Me thinks you need 120/220 SiC
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jamesp
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Post by jamesp on Dec 3, 2014 7:18:58 GMT -5
I'm going to treat my slag glass as obsidian in my rotary so keeps us updated. I'm absorbing as much info and trials of just about everyone here Jimi, glass and obsidian is about the same. Good call treating them the same. The guys that can put the shine on those need to be congratulated. I wish you luck. Looks like the vibe makes it easier, the rotary has been a challenge for me anyway. Glass is like Mohs 5.5, but the difficulty is the way it pits and fractures on the skin. Glass/obsidian dances to it's own drummer, yes it is soft, but it is also hypersensitive to sharp grit and impacts. Laughing, I think this load of obsidian has been run 5 times, still no polish. Got a test load in the vibe, it is making headway, best attempt so for. But the rotary attempts whipped me. My best attempt(scratched and dull):
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jamesp
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Post by jamesp on Dec 3, 2014 7:51:19 GMT -5
<------ Polish Dance Why do you have 220 in AO instead of SiC ? I think I recall your 500 being AO as well? You go from 46 SiC to 220 AO in every batch? Me thinks you need 120/220 SiC I agree 100% captbob. FACT. The AO 46 run in the rotary may be for vengeance. ha. Not really. I do want to skin off the impact bruises completely off. So the coarse grit. At this point I can not tell if I am bruising it again. And I do not have any 120 grit. If I did, I wold have used it, SiC or AO. Preferably the SiC. So, I may take the obsidian in the 46 in the rotary and put it in the vibe with 46 and see if the vibe will break the 46 down to 120 to 220 and so on. Hoping that the vibe will solve all problems with it's 'grit breakdown' capability. The load of obsidian in the vibe: So far, it has run two times, two days each time, in AO 220. After each 2 day run the AO 220 was broken down to nothing. Attempting to grind away the bruises from the trials with the vibe, doubling up on 220 runs. Today I will clean out and start it on AO 500. The 2 runs in 220 seem to be a vast improvement-seems...SEEMS.... I will say, those 2 inch obsidian nuggets are pure hell. They are the biggest problem. They have about all the bruises. The little stuff is a lot easier to work with, about bruise free. Had I had a rotary full of 1 inch pieces life would have been a whole lot easier. Not to make excuses, but they are bruisers.
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Post by orrum on Dec 3, 2014 8:15:10 GMT -5
Hey James they advise not to run anything below 220 in a vibe. Apparently it eats the vibe up also if you use coarser grit.
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jamesp
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Post by jamesp on Dec 3, 2014 9:13:03 GMT -5
Hey James they advise not to run anything below 220 in a vibe. Apparently it eats the vibe up also if you use coarser grit. Ah, orrum, my party is spoiled. How can you say such. LOL. You have jogged my memory, I have heard this. So, I looked at the instructions, and they say 80 SIC is fine, or suggested for coarse. That Viking has a thick belly full of some kind of galactic rubber in it. Apparently designed for coarse grit. Thanks for the heads up. Where are you orrum ? View of thick rubber:
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Post by orrum on Dec 3, 2014 18:15:53 GMT -5
I am in Quartzsite Az. Taking gem and lapidary plus silversmith lessons until the end of Feb. Living for free in the desert, just another rubber tire tramp!
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jamesp
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Post by jamesp on Dec 3, 2014 18:39:54 GMT -5
I am in Quartzsite Az. Taking gem and lapidary plus silversmith lessons until the end of Feb. Living for free in the desert, just another rubber tire tramp! Good for you orrum. i envy. learn bunches so you can post photos. Sounds like a trip of a lifetime. Getting homesick ?
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Post by captbob on Dec 3, 2014 19:26:59 GMT -5
hold on... the 46 is AO also??
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jamesp
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Post by jamesp on Dec 3, 2014 19:37:01 GMT -5
hold on... the 46 is AO also?? yes, why do you ask ? I moved the vibe obsidian to AO 500 today. Should start to see polish soon. It still has pock marks in it though.
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Post by captbob on Dec 3, 2014 19:59:55 GMT -5
Just the different way it breaks down as compared to SiC grit. Both will break down to smaller sizes as they get used up, but SiC more like fractures keeping it's sharp edges, while AO gets more rounded as it breaks down.
I have never used AO under 500 as it just doesn't make sense to me if I'm trying to grind rocks. SiC is more aggressive. I usually even use SiC 500 instead of the AO 500 I have and just run it awhile so it is much finer than 500 by the end of it's run.
Have you used SiC grits and switched to AO for a specific reason?
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jamesp
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Post by jamesp on Dec 3, 2014 20:27:24 GMT -5
Found a 5 gallon bucket of AO 220 for $20 at a junkyard, and the grit salesman's gave me a bunch of AO 400 and AO 500. My SiC 220 and SiC 500 ran out so i started using the AO 220 and 500 instead. Never noticed a difference. Same result/same amount of time.(A week in the rotary, each grit). That was with agate. I guess it is not that demanding to remove the scotches from the last grit step, so the AO is OK. But coarse rounding agates demands SiC.
Then came the obsidian saga, and the AO 46 wears it fast. But will not touch agate. And the AO 220 sure seemed to remove the scars from the AO 46 on the obsidian. It even made it smaller, AO 220 removed a lot of material on the obsidian. After 10 days in AO 220 the obsidian was running in mud.
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jamesp
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Post by jamesp on Dec 5, 2014 18:59:18 GMT -5
Hopefully a thick enough layer has been removed to get rid of the frost damage in AO 46 for 6 days, Went to AO 220 today. The 220 cuts it fast too. Transferred the unspent AO 46 to another tumble. Looks like the obsidian is not the fast tumble I pursued. Part of it is in AO 500 in the vibe. So it grinds fast, it vibes slow. 3 days in 500 and seeing a shine. Then a couple days in AO 1000 and AO 14,000. and 50,000 if needed. About 45% glass filler: Heavy frosting on edges gone Whole batch, again
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Post by connrock on Dec 6, 2014 6:59:05 GMT -5
I think the reason for the obsidian taking a long time in the vibe in 220 is because it has such a rough finish on it after the 46 in the rotary.Six days is a pretty short run! connrock
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jamesp
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Post by jamesp on Dec 6, 2014 10:06:56 GMT -5
I think the reason for the obsidian taking a long time in the vibe in 220 is because it has such a rough finish on it after the 46 in the rotary.Six days is a pretty short run! connrock That is a long story, this portion of the obsidian in the vibe was at AO 500 in the rotary. Sorry about the confusion. I did run the 500 obsidian in the vibe twice in 220 to try to remove the bruises. The other portion of 500 obsidian was in the rotary with AO 46 obsidian ran 6 days, and is now in the rotary with AO 220. The two vibe runs @ 220 did not remove all the old bruises. So the larger portion is being rerun in 46 and 220 in the rotary to get rid of the bruises. Then to the vibe. I obviously bruised it deeply. Deeper than I thought. Moral to the story-Don't bruise your obsidian !! Man was I spoiled. Agate ain't nuthin compared to obsidian. One headache after the other. I grabbed the wrong bull to experiment with. James does not care, I has learned a lot
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quartz
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Post by quartz on Dec 6, 2014 22:18:55 GMT -5
Wouldn't say you grabbed the wrong bull to experiment with, you grabbed a real tough old bull that taught you, and the rest of us, a whole bunch. Thanks for sharing your experiment with so much detail.
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jamesp
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Post by jamesp on Dec 6, 2014 23:57:44 GMT -5
Wouldn't say you grabbed the wrong bull to experiment with, you grabbed a real tough old bull that taught you, and the rest of us, a whole bunch. Thanks for sharing your experiment with so much detail. Thanks Larry. not the first whoopin. who's next ?
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