jamesp
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Post by jamesp on Dec 5, 2014 10:49:23 GMT -5
pre-grindind a load for the rotary tumbler from Andy bsky4463. Real nice Montana rhyolite he self collected. It is a tight grained rhyolite. I heat treated it, which reduced the graininess further. Was thinking about using glass media in the vibe for finish steps.
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bsky4463
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Post by bsky4463 on Dec 5, 2014 11:02:47 GMT -5
Interested in the graininess reduction....way cool. This material is pretty hard - guessing mohs 6ish. I have a small batch in the rotary for rough grind and will move to vibe this weekend. I am using my normal ag/jasp recipe and using ceramics for filler. Cheers
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tkvancil
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Post by tkvancil on Dec 5, 2014 11:49:06 GMT -5
Yuppers, rhyolite is right around mohs 6. It should do just fine in a vibe with or without any tricks. Don't know about your Viking but my Thumlers is gentler than it looks. Put a finger in while the rocks are rolling and I was surprised at how "soft and smooth" it felt.
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jamesp
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Post by jamesp on Dec 5, 2014 13:00:21 GMT -5
Thanks Andy/Ken. Mohs 6 sounds right to me. I am pre-grinding it and it is a tough material. Hardness vs toughness can be different properties. I don't think it knows a fracture.
Andy- I would say the heat darkened it a bit. Definitely glassier. Real nice stuff. The knappers say rhyolite has varying amounts of silica. The higher percentage silica material is easy to work and grain reduction from heat does better with higher silica content. May help with the polish too. Tumbling about the whole MFRB. Some reduced w/trim saw, some chipped. Fun to cut and chip by band direction Ken- Finger seems to get a mild massage in the Viking. I will say the rocks are quite warmer than the surroundings. Could be the motor below. And a smell of grit or rocks radiates. Crazy process.
Thanks, sounds like a laid back tumble, am happy.
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Post by rockpickerforever on Dec 5, 2014 13:22:14 GMT -5
I feel a bout of experimenting and a bunch of pics coming on...
Eagerly anticipating.
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jamesp
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Post by jamesp on Dec 5, 2014 14:23:29 GMT -5
I feel a bout of experimenting and a bunch of pics coming on... Eagerly anticipating. Dear rockpickerforever Jean: I am pleased to announce I may be getting the mixed obsidian batch you so kindly sent me close to a polish. The portion in the vibe. After being rotary tumbled 4 whole times state to finish. it looks like things are looking up finally. Most of them are being retumbled to remove the bruises from the other 4 runs. Please issue 'A' for effort. They started out giant, and now they are small,LOL. I know have a rich volcanic ash loam covering about 2 acres. Years later geologist will be looking for a volcano close by-the first in Georgia. Sincerely Jamesp PS Ken and Andy said rhyolite is easy. This I am thankful for.
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Post by rockpickerforever on Dec 5, 2014 15:56:02 GMT -5
I am sure the long-tumbling obsidian will be to die for. I am waiting to see the wonder stone (rhyolit) from Andy.
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bsky4463
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Post by bsky4463 on Dec 5, 2014 16:06:06 GMT -5
I am sure the long-tumbling obsidian will be to die for. I am waiting to see the wonder stone (rhyolit) from Andy. Anticipation makes the heart grow fonder... This is jamesp 's party...I am just along for the ride. Cheers
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jamesp
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Member since October 2012
Posts: 36,159
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Post by jamesp on Dec 5, 2014 16:09:48 GMT -5
I am sure the long-tumbling obsidian will be to die for. I am waiting to see the wonder stone (rhyolit) from Andy. Anticipation makes the heart grow fonder... This is jamesp 's party...I am just along for the ride. Cheers Aiming to make it good for all. All is great material, monkey is on James' back.
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bsky4463
fully equipped rock polisher
Member since September 2013
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Post by bsky4463 on Dec 5, 2014 16:15:20 GMT -5
Escaping through the rhyloite fields, I came across an empty space It trembled and exploded, left a bus stop in its place The bus came by and I got on, that's when it all began There was Cowboy jamesp at the wheel of the bus to never ever land .....more Grateful Dead (the other one) lyric adaptations...cheers
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Post by captbob on Dec 5, 2014 17:14:15 GMT -5
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jamesp
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Member since October 2012
Posts: 36,159
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Post by jamesp on Dec 5, 2014 18:33:11 GMT -5
Escaping through the rhyloite fields, I came across an empty space It trembled and exploded, left a bus stop in its place The bus came by and I got on, that's when it all began There was Cowboy jamesp at the wheel of the bus to never ever land .....more Grateful Dead (the other one) lyric adaptations...cheers Jammin w/the Dead eh Andy ? Song's a trip. Wished I was mentioned in one of their songs. Great imagination.
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jamesp
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Member since October 2012
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Post by jamesp on Dec 5, 2014 18:42:30 GMT -5
That is the same rhyolite. I have none polished. hopefully in about 6 weeks.
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Post by rockpickerforever on Dec 5, 2014 19:06:31 GMT -5
I am sure the long-tumbling obsidian will be to die for. I am waiting to see the wonder stone (rhyolit) from Andy. Anticipation makes the heart grow fonder... This is jamesp 's party...I am just along for the ride. Cheers I believe it is absence that makes the heart grow fonder, lol. Anticipation just makes you wait fot it! Just ask Carly Simon. Ketchup, anyone? It's a lot like tumbling rocks!
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Post by connrock on Dec 6, 2014 6:55:10 GMT -5
Some rhyolite will undercut,,,,just sayin! LOL connrock
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jamesp
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Post by jamesp on Dec 6, 2014 6:58:26 GMT -5
Should finish pre-grinding the rhyolite today and get it rolling. Most of it is 1.5-2 inches, so on the big side. Will use crushed 60 grit SiC grinding wheels for smalls. Five inch wheels, one inch wide, from an industrial junkyard for $20/5 gallon bucket full. 30/60 SiC for loose grit. About 12 pounds rhyolite in 16 pound barrel. Turn at 32 RPM. This is almost half the load. Incandescent light(reds not that red): Flash(reds distorted again):
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jamesp
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Member since October 2012
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Post by jamesp on Dec 6, 2014 7:17:47 GMT -5
Some rhyolite will undercut,,,,just sayin! LOL connrock When chipping this i noticed the purple areas would cause a wave or valley in the smooth fracture faces. No doubt a difference of some sort. Devious behavior in the purple zone connrock. I have used crushed AO 60 grit wheels in removing the limey chert off of coral. They reduce to mud in a couple of weeks. This time I found nasty little 60 grit SiC grinding wheels. So I bought about 70 pounds of them for $40. Curious to see what will happen when I crush them to smalls for this load. Still about 100 pounds of them left at the junk yard. I can get them for $50. Price is right anyway. Wondering if they will speed things up as filler. PS Talk about slow, that dang obsidian in the vibe. Running 4th day in AO 500 and slowly gets shinier each day. Agate would have been about done. Obsidian is real slow taking a shine.
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Post by connrock on Dec 7, 2014 6:19:25 GMT -5
I'll be interested in seeing what happens with the crushed sic grinding wheels as smalls. How small is small? I still think the obsidian should have been run longer in rough to let the grit break down and create a much smoother surface before the 500 runs. The 500 grit doesn't really remove much material and I think the reason it's taking so long in the vibe is due to that rough surface. Good luck,,, connrock
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jamesp
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Post by jamesp on Dec 7, 2014 7:32:48 GMT -5
I'll be interested in seeing what happens with the crushed sic grinding wheels as smalls. How small is small? I still think the obsidian should have been run longer in rough to let the grit break down and create a much smoother surface before the 500 runs. The 500 grit doesn't really remove much material and I think the reason it's taking so long in the vibe is due to that rough surface. Good luck,,, connrock I forgot, the AO grinding wheels break down to grit in 2/3 barrel spinning fast with the coral in the rough step in a few days. These SiC wheels cracked with the hammer easier than the AO wheels Tom. So they may be loose grit in a few days. i only added 1/2 the normal dose of SiC 30/60 because of the added grit from the wheels. So an over dose of grit may be present. Running low on coarse grit, so I will try using the wheels for coarse grit. I used the broken pieces of AO wheels to grind the lime layer off the coral. Some of the lime/chert layer was 1/2 inch thick. So that thick layer had to be removed before I got to the agatized coral inside. The AO did not grind the coral worth a darn, but it sure ate away at the lime coating. I would fill the barrel 3/4 full, by morning it would be less than 1/2 full, barrel full of white lime mud. The tub on the left is whole corals 2-3 inches in size. That would be a normal load for a 1-2 day tumble. the tray on the right was after a couple of days running. they were loud Once the coating was removed I heat treat the coral to bring out the color, then chip it up for tumbling. Same yellow/orange coral above after being heated and chipped for tumbling: Looks like this tumbled, wet after roughing. The heat changes it's color a bunch:
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Post by connrock on Dec 8, 2014 6:36:59 GMT -5
Look at the finish on "wet after roughing" coral compared to the roughed obsidian! The coral is MUCH smoother then the obsidian. connrock
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