10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 2, 2009 19:37:48 GMT -5
Is it possible to mix in some small pieces of snowflake obsidian in an apache tears tumble? I know that you're supposed to tumble "tears" solo. My "tears" are really larger obsidian nodules than what's probably than the normal size for tears. They have a lot of chips and I'm basically looking for a short cut to get them rounded up a little quicker. I also know that its typically a bad idea to try and hurry the tumbling process... but I guess I'm considering it anyway.
Thanks,
Scott
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Post by johnjsgems on Apr 2, 2009 22:32:28 GMT -5
It's all volcanic glass so should work together. Good luck. Obsidian isn't the easiest material to tumble.
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Post by Condor on Apr 3, 2009 7:32:53 GMT -5
They both the same. Obsidian. So you should not have much of a problem tumbling them. I like to tumble them using the rotary followed by the vibe. Works well that way, but even with the rotary alone, it will work just the same.
Condor
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 3, 2009 11:17:18 GMT -5
Thanks. I'll give it a shot...
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Post by LCARS on Apr 4, 2009 1:25:49 GMT -5
Don't be scared of obsidian, it's not that hard to tumble in a rotary and get good results, you just have to take into consideration it's specific "needs".  I think where some poeple might be going wrong with it is trying to do it in with a "mixed" load. It's tempting to put a little of everything you've been collecting into the barrel at one time so you can have a nice variety of rocks but the harder rocks in the mix beat the heck out of the softer ones not to mention the different shaping and smoothing times needed. If you mix obsidian with agate for instance, your obsidian will be oblivion before the rind is even ground off the agate.  Tumbled by itself obsidian/desert glass/apache tears etc is all part of the same "family" of simillar material so as long as you tumble your obsidian with other amorphous silicas (a.k.a. glass) and take some basic measures to accomodate the material and adjust your tumbling recipe accordingly, you can get spectacular results even with the most reputedly stubborn stones to tumble. |
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 5, 2009 0:13:36 GMT -5
I was able to pull out maybe a 1/2 pound of obsidian that is done with the course grind stage. I keep checking because I don't want the small pieces to get too small. I added in more snowflake obsidian to balance out the volume in the tumbler. I have over 40 pounds of obsidian to play with so this may turn into the never ending tumble...
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Post by LCARS on Apr 5, 2009 12:58:39 GMT -5
It's not unusual to have to tumble a couple loads of coarse before you have enough volume of assorted sized material that is shaped enough to move on to the fine grit stage.
Patience Grasshopper. ;D
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 6, 2009 18:37:26 GMT -5
LOL "grasshopper"
This is why I need to learn the science of polish. I need the formula. X # of scratches at Y level of magnification indicates an Z micron polishing compound. X * Y = Z.
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 7, 2009 16:56:16 GMT -5
I pulled out another quarter pound of obsidian that's finished with course grit last night. Another problem with this tumbling method is the obsidian slivers you get fishing around in a 6 lb drum for finished pieces.
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lparker
fully equipped rock polisher
Still doing too much for being retired!
Member since March 2008
Posts: 1,202
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Post by lparker on Apr 11, 2009 19:27:01 GMT -5
I get a better shine with obsidian by flaking it for arrowheads...talk about slivers.......
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Post by MyNewHobby on Apr 11, 2009 21:13:35 GMT -5
Even though I still cannot find my behind with both hands when it comes to tumbling ....
I have/had heard that Apache Tears are fragile and should not be tumbled with anything else.
I have some raw Apache and very hesitant to tumble (mind I have more goodies that I can deal with) them with anything else.
Help me out here ....
As always .... my humble thanks
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Apr 12, 2009 9:04:57 GMT -5
The apache tears are coming out fine in my multi-flavor obsidian tumble. So based on my very limited personal experience you should be okay. However, if you have more patience than I do your probably better off safe than sorry. I have a ton of obsidian I'm trying to make a dent in so I'm pushing the envelope tumbling it all together in my biggest tumbler (6#).
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on May 2, 2009 10:31:58 GMT -5
For my obsidian tumbles I went from 60/90 SiC to 500 AlOx to optical cerium oxide. I am not happy with the results. First, even though I practically topped off the barrel with plastic pellets about 10 rocks ended up with tiny chips. Second, I think the shine looks milky. See for yourself: Regular old black obsidian  Snowflake obsidian - I think this came out better than the other types which may be part of the problem. Maybe its a shade harder than the rest?  Mahogany and mahogany gold sheen. Some of the gold sheen has really nice flash when wet. In this picture it looks like I polished them with a Hershey bar.  I have some of the next grade of cerium oxide. Should I try that or do I need to pony up for some tin oxide? I'm out of 60/90 SiC now so I need to order supplies anyway. |
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Post by creativeminded on May 4, 2009 7:26:20 GMT -5
I have tumbled batches of put obsidian mixed with apache tears. I only let them run a week in each stage. From the looks of your stones I think what you did is jumped to quickly from 60/90 to 500 and then to polish. I get great shines when I put in a 120/220 stage, 1000 stage and a Tripoli stage. Here is one of my obsidian batches.  Tami |
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on May 4, 2009 7:45:43 GMT -5
Those stones look awesome. I didn't want to go with 120/220 SiC because I didn't want the stones to get any smaller. I can't argue with your results. I don't have any 1000 grit though. I have 60/90 SiC, 120/220 SiC, 500 AlOx, Tripoli, AlOx polish, and two grades of Cerium Oxide. Does anyone have another effective Obsidian recipe that doesn't use 1000 grit?
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ejs
spending too much on rocks
Member since July 2008
Posts: 478
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Post by ejs on May 4, 2009 9:30:07 GMT -5
I don't think you have to worry about the 120/200 making your rocks much smaller. In my experience, 120/200 SC mostly smooths (rather than reduces) the rocks. You will get some reduction, but not enough that you'll regret it in the end (I think).
I would think that a path of 60/90 -> 120/200 SC -> 500 AO --> pre-polish -> polish should work for you.
If I were you, I'd take those stones that you are unhappy with and go back to the 120/200 stage and run them again. I like 7 days in 120/200, 10 days in pre-, and 14 days in polish, but I spend more time on most. Try going back to 120/200 and spending a week in each stage. Go for it!
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
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Post by 10thumbs on Jul 9, 2009 15:05:53 GMT -5
Just an update: I re-ran my obsidian from scratch. The babyflake and mahogany obsidian came out nice. The nodules and tears all ended up with white edges (spalling?). So in my personal experience I would not recommend mixing the tears with other types of obsidian. I am rerunning the tears/nodules now (3rd times the charm) starting from the 120/220 stage as the shapes are already nice except for the white edges.
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Post by Bikerrandy on Jul 9, 2009 22:35:52 GMT -5
One thing that seems to help with the white edges is plastic pellets. I use many of these when tumbling stuff like obsidian, sodalite, tigereye and other softer stones. I use a pound of them in a ten pound batch of rocks.
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Post by Jack ( Yorkshire) on Jul 10, 2009 2:48:00 GMT -5
Hi 10thumbs, Why not run them another week (Rotary) in the 500 SC as grit breaks down it should be around 1000Grit in a weeks time anyway Don't skip stages it will show up in the end polish Im sure others will add their comments if im wrong I have tumbled Obsidian with my other rocks and done quite well see this link with other rocks along with Black Obsidian and Maghony Obsidian Tom (conrock) sent me from USA 2 year's ago img.photobucket.com/albums/v357/john-edward/E-VibeApril2.jpgThese were finished off in a vibe (Conrocks Recepie) from stage 2 Grits used 220G, 500G ,1000G ,Tripoli, Rapid 61. Hope this helps Jack Yorkshire UK |
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10thumbs
spending too much on rocks
I want to be reincarnated as a dog.
Member since March 2009
Posts: 480
|
Post by 10thumbs on Jul 10, 2009 7:15:42 GMT -5
Perhaps it was the baby flake/snow flake obsidian that was bullying the tears in the tumble. I've been putting plastic pellets in every stage of my obsidian tumbles as it drastically reduces the chipping. One little chip and it's a demotion back to 120/220.
I know that SiC fractures into smaller sharp pieces. I thought that characteristic was unique to SiC. Is AO supposed to do the same thing? Or are you using 500 SiC?
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