Steve
has rocks in the head
Member since June 2005
Posts: 506
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Post by Steve on Jul 29, 2012 21:36:51 GMT -5
These are from a batch of obsidian that I finished a few days ago. These were done completely in a vibe. I think next time I'll round them off in a rotary first. I laid a piece of white cloth over a full spectrum "Happy Light" laid flat. Then set the obsidian on this to try to get some back lighting.
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Post by paulshiroma on Jul 29, 2012 21:54:16 GMT -5
Looks great, Steve! Those look like they took a solid shine. Paul
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Post by Bikerrandy on Jul 30, 2012 19:46:00 GMT -5
Those are smooth!! Awesome job
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hand2mouthmining
spending too much on rocks
Purveyors of California Gem Rock
Member since September 2011
Posts: 495
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Post by hand2mouthmining on Aug 14, 2012 14:45:10 GMT -5
Mmmmm ... Yummy O'Sidian!
Since one of the big complaints we hear about tumbling obsidian is "It won't polish up!", we'd really appreciate your polishing stage secret ... It ROCKS!
Best regards, Kris & Al Hand-2-Mouth Mining
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riverrock
fully equipped rock polisher
Member since April 2010
Posts: 1,395
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Post by riverrock on Aug 15, 2012 7:46:04 GMT -5
Those look very shiny. I got some from Fish i think i am going to try Krystee's tutorial .
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m83striker
starting to shine!
Member since July 2012
Posts: 36
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Post by m83striker on Aug 15, 2012 15:17:07 GMT -5
I've got about another week for my first batch of Mahogany obsidian and I can only hope that it turns out as smooth as yours. They look amazing!!
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Aug 15, 2012 15:59:17 GMT -5
I had a batch in polish, now for three weeks.
A) it looks worse than it did at 800 B) some pieces are polished on the flats C) for some reason I keep getting a dried plug of polish and plastic beads at the mouth of my PVC barrel.
I am going to let these sit until I can get a vibe and follow krystee's recipe better.
That is unless OP will share his tumbling technique in detail! Please!!
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Steve
has rocks in the head
Member since June 2005
Posts: 506
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Post by Steve on Aug 15, 2012 20:19:57 GMT -5
It took several failed experiments before I was able to tumble obsidian. It would polish on the flats and frost on the edges. One solution to to make sure there are no edges which is why tears often come out quite nice.
The frost is being caused by micro fractures and chips. One way to stop this is to polish in a vibe and to fill the vibe to capacity and keep it there.
On the Lot-O this means stuffing it full and keeping extra almost polished pieces available to stuff into the Lot-O as space opens up during the first few minutes of running. I've gotten really nice results polishing obsidian sphere preform trimmings this way. These trimmings are triangular with lots of edge.
In the ultra vibe just fill to the very top of the inside pillar. If you polish in a rotary, fill it more than usual and use a lot of filler for buffering - I use plastic pellets. You need to make sure that the obsidian is sliding and not colliding.
Frosting on the edges of obsidian is the sign that the action is too violent. Generally when you have frosting you will also see larger chipping.
I did the above batch in an ultra vibe-10. I had some other already not quite polished obsidian that I added to the batch at each stage to keep the volume at full capacity. You may be able to get the same result with ceramic, I've not tried this myself.
In a rotary I've been told that sawdust (very fine sawdust that would fall through a screen - typical screen door screen) really helps with obsidian - I've seen the results and they were fantastic. Haven't yet tried this myself.
Shotgunner - if you leave obsidian in polish for too long you get worse results. The longer you run it, the more likely you'll get frosting, which cannot be removed in the polish stage. Unlike other rocks, timing is actually important with obsidian. Not long enough you don't get a good polsih --- let it run too long and you'll ruin the polish you had.
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hand2mouthmining
spending too much on rocks
Purveyors of California Gem Rock
Member since September 2011
Posts: 495
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Post by hand2mouthmining on Aug 16, 2012 13:16:51 GMT -5
Thanks for the tips, Steve!
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Aug 16, 2012 15:26:43 GMT -5
thanks Steve. My tumbler is very fast so I filled it nearly 100% with obsidians and plastic pellets hoping to minimize the "fall" and the chipping.
I think I will wait for the vibratory because the MJR is too violent.
Thanks for the advise.
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Aug 17, 2012 8:32:00 GMT -5
Nice Ob. Seems like every batch of it I do comes out different in some way.Some good,some not so good.
snuffy
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Post by Toad on Aug 17, 2012 15:27:51 GMT -5
Fantastic work.
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