braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 29, 2017 18:34:06 GMT -5
First off I'm all rotary....A-R12 Thumler for rough and 3 LB Lortones and Thumlers for stages 2 (220), 3 (prepolish), and 4 (polish). The rocks in the photo are #2 ready but some of them look like they could go directly to the polish stage?? I'm wondering if that happens with some of you guys and gals? I took this photo for reference/comparison's sake as I'm sticking (for now) to my routine which is: rough tumble (no new grit added weekly but maintain slurry from previous rough tumbles to milkshake consistency) in A-R12 and weekly remove perfect or near perfect (perfect being smooth all round to touch and shaped nice). Then 2 weeks each of stages 2, 3,and 4 all with plastic tile spacer media to top up their own 3lb barrels. I'll take another photo of these same rocks after 2 weeks of #2 to see if the near perfect rocks (small pits you can hardly see but can feel) get smoothed out...kind of an experiment I guess. But I'm wondering if I'm being too fussy what leaves the rough stage though and maybe I'm wasting time? Not really worried about the time but more efficient makes sense. Anyways I'm sure others have been there done that so I'm open to any and all advice...
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 29, 2017 19:07:44 GMT -5
What are you using for your Stage 1 grit ?
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 29, 2017 19:21:07 GMT -5
I'm using slurry from previous rough tumbles but not adding any new... so whatever grit is left in the previous slurry is all...
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 29, 2017 19:24:03 GMT -5
Aluminum Oxide or Silicon Carbide
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Post by TheRock on Sept 29, 2017 22:25:20 GMT -5
That Flat Round Grey one Bottom Middle looks like it needs its corners Rounded a Bit other than that I would give you an A instead of an A+ for finish 1st Stage very good work. How long they tumble for? And what was your recipe? First stage grit and did you use any kitty litter? Thanks ~Duke
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 29, 2017 22:52:29 GMT -5
I only got the A-R12 a few months ago and since then I do all my rough tumbling in it...no kitty litter only the slurry I've saved from previous rough tumbles so the only grit that's in there is the "coarse" grit that still is or was in there. I assume it's broken down to something finer than "coarse" by now. How long did they tumble for? Don't know...somewhere between a week and a few months. As I said above I check weekly and remove what I think is ready for #2 till I got enough to do the #2 tumble. That's what's in the photo. I replace removed rocks with new rough and add Borax weekly...
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Post by captbob on Sept 29, 2017 23:16:14 GMT -5
That's pretty interesting results for using no grit other than the initial grit you started with. You might just put those grit makers out of business. What was the grit you started with? (what #) Can you still feel grit when you rub the slurry between your thumb and fingers or is it spent? 30 or maybe even 46/70 might not be breaking down in that soft sided barrel. I have 2 of those tumblers and only use then for the polish stage - or very "soft" rocks.
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 30, 2017 0:17:47 GMT -5
I started with "46/70" (from the label) and when I used it up got some "coarse" (from the label) which came from Thumler according to where I got it from, so the slurry is a mix of both... and no the slurry is smooth city (just checked). I've felt the slurry when there was grit in there so I'm sure there is none now. If there's any in there its not coarse enough to feel. My first batch in my Lortone 3A ( a year ago) did the same thing...came out shinier than they were supposed to?? and when I put them through 220 and then pre-polish they were dull which really threw newbie me for a loop...after asking in here what was going on I put them in polish and they came out acceptable. So all of the above plus I've read along the way somewhere that some have tumbled without using grit lead me to try a rough tumble with no grit (or at least no new grit) and the photo is the result. So I guess I'm trying to determine how all this fits in with conventional tumbling wisdom.
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Post by youp50 on Sept 30, 2017 7:57:50 GMT -5
It does not fit with "conventional" wisdom.
Conventional wisdom is being upgraded by nonconvetional thinking.
I think I am stuck in conventional methods. Weekly clean out, I do add clay to the mix after clean out. I also ad grit mid week.
Silicon carbide does break into smaller pieces during the tumbling process. There have been posts about grit breakdown vs time. I have not question the result, it seems to be consistent with my observations. That's why I ad grit mid week.
If you have decent shape and form rocks, put them in the polish.
I would venture a guess that the stones you have did not need much coarse grind time. Letting it run on would have the stones breaking down the grit and moving into finer grit stages "automatically".
Rock on and forget conventional wisdom. A few people here do just that and most all of us benefit from it.
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Sept 30, 2017 8:46:15 GMT -5
I do know that there are folks out there that go from rough grind direct to polish. They will let the rough charge roll for an extended time, one month or more. By that time the silicon carbide grit has broken down to a very fine mesh. Since 600 SIC can be used as a pre-polish, anything broken down that far or farther, would create an acceptable surface for a polish.
So the slurries you are reusing still have grit in them, albeit finer than the original mesh. The fact that it cannot be felt doesn't mean its not there. In my experience somewhere around the 300 mesh area it's hard to tell by feel or otherwise that it is there. I once weighed a batch through the finish stages. Even in the 600 grit there was some measureable loss of mass.
I would hazard a guess that you will get diminishing returns with the reused slurries. A fresh batch of jagged crushed rough would likely do little rounding.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,666
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Post by Fossilman on Sept 30, 2017 9:45:25 GMT -5
I also use my old grit slurry (Stage 1),but add one tablespoon of grit to the mix...I would roll them through each stag,but not as long as rough..
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 30, 2017 11:06:18 GMT -5
I also use my old grit slurry (Stage 1),but add one tablespoon of grit to the mix...I would roll them through each stag,but not as long as rough.. What tumbler are you using for stage 1?
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Post by TheRock on Sept 30, 2017 11:37:12 GMT -5
Very Interesting and something to ponder for a newb like me. I think Im gonna crack the barrels today and add some "TRUE GRIT" Cheers ~Duke
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Mark K
Cave Dweller
Member since April 2012
Posts: 2,528
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Post by Mark K on Sept 30, 2017 13:07:33 GMT -5
I put some AZ pet wood in a tumbler this past winter with a little polish and let it go for a few weeks. It came out polished and still shaped like it went in. Kind of neat, but I like the more conventional method better. I use one of those stupidly expensive yellow tumblers from off of Ebay with the PVC barrel to tumble stage one. The barrel wore out years ago, so I load 3lb barrels and use it for them. It rolls faster than a thumler, so it processes much faster. Generally, I have the barrels rolling for 2 days and they are ready to go to the next stage. I do lots and lots of stage one and then when I run out of stuff to run, I use the vibe for the rest of the stages.
By the way, don't buy those yellow tumblers from Ebay, the guy is a real asshole and his warranty is junk. You can't comply with the requirements to keep the warranty. The bearings are very poor quality and it is made to be a real PitA to adapt it to take good ones.
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Luminin
spending too much on rocks
Member since August 2017
Posts: 400
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Post by Luminin on Sept 30, 2017 16:56:34 GMT -5
This is really interesting. fossilman, I've seen you mention reusing slurry before, can I ask for one of those great videos that you do to see how? Guessing you don't dump your barrels over a window screen like I do and just let the slurry run into the grass. lol
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 30, 2017 18:44:37 GMT -5
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Luminin
spending too much on rocks
Member since August 2017
Posts: 400
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Post by Luminin on Sept 30, 2017 21:59:10 GMT -5
That's excellent Wooferhound! So many benefits to that!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Oct 2, 2017 7:12:41 GMT -5
Some fine looking granites there braat. Lots of aluminum oxide in those granites you tumbled. Most felspar is full of aluminum oxide particles. Granted felspar is softer than quartz but it still has aluminum oxide particles. Aluminum is the 3rd most common element in the earths crust. Much of it in felspar. Granite is composed of mostly quartz and felspar. Weathering granite makes felspar rich clay. Felspar rich clay is often 20-30% aluminum oxide. So your slurry probably has a higher dose of aluminum oxide than the recommended dose of a tumbling recipe. Crude albeit, but it's there. And has the ability to put a matte polish on your rocks after the short lived brittle silicon carbide has broken down. Side note: Ceramic media also has a high percentage aluminum oxide. Denser high quality media typically has higher Al2O3 content. Not all is created equally. Harbor Freight ceramic media. The cheap stuff. 40% aluminum oxide: Name 5 lbs. Medium Ceramic Abrasive Polishing Tumbler Media SKU 60547 Brand Central Machinery® Abrasive material 49.6% silicon dioxide (SiO2); 40% aluminum oxide (Al2O3); 5.5% potassium oxide (K2O); 2% sodium oxide (Na2O); 0.4% iron oxide (Fe2O3); 2.5% calcium oxide (CaO) Application Polishing And Light Deburring Back to naturally occurring aluminum oxide: Maybe another way of looking at it is looking at the composition of the earth's crust. Note 15% is Al2O3, aluminum oxide. If you live in a predominately granite area your clay is likely 25 to 30% aluminum oxide. Since I live in the leading kitty litter producing state (Georgia) I will say that your kitty litter is likely high in Al2O3 if materials came from here. Fuller's earth is used and it has a high content of kaolin which in turn has a high percent Al2O3(both from weathered/eroded felspar). Not saying you will get a perfect polish using raw clay or kitty litter. There are other ingredients that will likely impede a great polish.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Oct 2, 2017 12:11:07 GMT -5
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Oct 2, 2017 22:12:55 GMT -5
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