denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 6, 2021 13:57:26 GMT -5
Hello, I just started rock tumbling this year. With my small Nat Geo tumbler, my rocks always came out shiny. Now I'm using the bigger Nat Geo tumbler--3 pounds--and my rocks are not shiny or polished at all. I let them run for 10 days on Speed 1. Am I doing something wrong? Or does the small tumbler just work better? What can I do to consistently get highly polished rocks? Thank you
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heathervee
having dreams about rocks
Member since August 2021
Posts: 57
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Post by heathervee on Nov 6, 2021 15:11:33 GMT -5
Make sure your tumbler is 3/4 filled, including rock and fill media. And how much polish are you using? Are you using the nat geo polish?
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 6, 2021 15:47:56 GMT -5
Yes, using the Nat Geo polish, 1 scoop for every 1/2 pound. If the rocks don't make it 3/4 full, what do I use to fill it?
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Post by knave on Nov 6, 2021 16:02:10 GMT -5
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heathervee
having dreams about rocks
Member since August 2021
Posts: 57
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Post by heathervee on Nov 6, 2021 16:22:48 GMT -5
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heathervee
having dreams about rocks
Member since August 2021
Posts: 57
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Post by heathervee on Nov 6, 2021 16:26:23 GMT -5
Also, maybe try a cleaning stage before and after your final polish stage. I do a run in grated ivory soap and clean water between every stage to make sure all the grit is gone.
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 6, 2021 16:36:49 GMT -5
knave, the scoop comes with the grit. It's between a tsp. and a tbl. spoon heathervee Thank you!
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heathervee
having dreams about rocks
Member since August 2021
Posts: 57
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Post by heathervee on Nov 6, 2021 16:48:42 GMT -5
denversue, I don't think you're using enough polish. Get a cheap metal measuring spoon set to use just for grit
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Post by knave on Nov 6, 2021 16:54:37 GMT -5
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hypodactylus
spending too much on rocks
Member since July 2021
Posts: 467
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Post by hypodactylus on Nov 7, 2021 16:47:33 GMT -5
There are so many things that can affect the outcome of your polish. Until you get some successful experience, I would stick to the following: - Tumble Agate or Jasper
- Tumble one kind of rock at a time
- Repeat stage one (with new grit each week) until the rocks are completely smooth
- Make sure the barrel is filled 70 - 75% with rock/media for each stage
- Use ceramic media starting with stage 2
- Use a real polish for the final stage (4000 grit or higher) - Not the NatGeo 'polish' (which is just a pre-polish)
I recommend you watch this video:
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 7, 2021 17:20:58 GMT -5
Thank you!
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heathervee
having dreams about rocks
Member since August 2021
Posts: 57
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Post by heathervee on Nov 7, 2021 17:31:24 GMT -5
denversue, I think you will really like agates. They are SO pretty and colorful. And sometimes you get one that is also an geode which is a lovely surprise! Plus they are hard to mess up, so great for us newbies!
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 7, 2021 17:42:24 GMT -5
Once I get the filler and some better polish, can I tumble rocks that have been sitting around for months, that didn't get shiny the first time?
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Post by knave on Nov 7, 2021 18:05:49 GMT -5
Once I get the filler and some better polish, can I tumble rocks that have been sitting around for months, that didn't get shiny the first time? Absolutely you can
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 7, 2021 19:06:46 GMT -5
thank you
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RedWingTumbler
having dreams about rocks
Member since April 2021
Posts: 65
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Post by RedWingTumbler on Nov 7, 2021 21:18:19 GMT -5
I have two of the Nat. Geo. 3-lb tumblers (and a third that I recently replaced the motor on, which now runs slower than the other two). My general stage 1 recipe (for Mohs 7 rocks) is to fill the barrel 3/4 full, water below the top level of rocks (this amounts to just over halfway up the barrel), 6 tablespoons of 60/90 grit, 3 teaspoons of Old Miser grit carrier kingsleynorth.com/old-miser-lapidary-grit-carrier.html, and run for 7 days at speed 3. I repeat this as many times as necessary, pulling out smooth rocks & adding more rough each week. I've gotten really picky about this & only let the smoothest rocks proceed to the next stage. Absolutely no sharp edges or pitting. When you rub the wet rock between your fingers, there should be absolutely no rough spots. When I have enough rocks ready for stage 2, I fill the barrel 3/4 full & add about 10% ceramics (compared to the volume of rocks) - this may get me to 80% full, but I don't worry about that. I'll shake the barrel a bit to get the ceramics to settle between the rocks. Water to below the top layer of rocks. Add 6 tablespoons of 120/220 grit & 3 teaspoons of Old Miser. Run for 7 days at speed 1 (all steps from here on are at speed 1). Pull out the smoothest rocks for stage 3 & put any that are not as smooth back in for stage 2. Any broken rocks go back into stage 1. If I don't have enough stage 2 rocks for a full barrel, I will often run some more batches in stage 1 until I do. In a pinch, I will add more ceramics to the stage 2 rocks to keep the barrel 3/4 full. For stage 3, I fill the barrel 3/4 full, including 10-20% ceramics (or lots of little rocks that are ready for stage 3). Water to below the top layer of rocks. Add 4 tablespoons of 500 grit (I use AO for this stage). Run for 7 days. Any broken rocks go back into stage 1. So far, I have noticed that almost all of the rocks I've tumbled only need a week in stage 3. I still check every rock to see that they feel very smooth - almost as smooth as polished rocks. For stage 4, I like to have the barrel about 80% full with rocks & ceramics. Any ceramics that I add for stages 3 & 4 should have already been tumbled to at least stage 2 or 3. I'm not too picky about this, since I often just grab a handful from a container of pre-tumbled ceramics. Just don't use any new ceramics past stage 1 or 2. Water to below the top layer of rocks (maybe even a little bit lower). Add 3 or 4 tablespoons of polish (I alternate between Aluminum Oxide & Cerium Oxide). Run for 7 to 9 days at speed 1. Any rocks that still don't come out perfectly shiny get set aside for the next polish batch, in which I will usually use a different kind of polish (AO or Cerium). For all of the stages, after I've closed the barrel, I turn it around a few times in my hands to get the water & grit to mix before I set it on the tumbler base. For softer & more fragile rocks, I add ceramics in stage 1 (maybe up to 50%).
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 7, 2021 22:13:55 GMT -5
Thank you. Why don't you use the grits that Nat Geo sells? I bought a big box of ther grit for Stages 1 through 4 and I use a half scoop for every half pound of rocks, like they say to do. I hate to waste them! Today I just bought a new Lortone tumbler and some "good polish" called tin oxide from The Rock Shed. Do you think that will work well? I looked for cerium oxide because someone else mentioned it, but I could not find it.
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RedWingTumbler
having dreams about rocks
Member since April 2021
Posts: 65
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Post by RedWingTumbler on Nov 7, 2021 23:35:46 GMT -5
Thank you. Why don't you use the grits that Nat Geo sells? I bought a big box of ther grit for Stages 1 through 4 and I use a half scoop for every half pound of rocks, like they say to do. I hate to waste them! Today I just bought a new Lortone tumbler and some "good polish" called tin oxide from The Rock Shed. Do you think that will work well? I looked for cerium oxide because someone else mentioned it, but I could not find it. The Nat. Geo. grits for stages 1 & 2 are fine. Their stage 3 grit (I think) is problematical, as it is 500 grit silicon carbide. I buy my grit either from the Rock Shed, or Kingsley North. For stage 3, I get the 500 grit aluminum oxide. As I understand it, particles of silicon carbide are angular, while aluminum oxide particles are round. To my way of thinking, round is better for polishing than angular. The stage 4 grit that comes with their tumblers (& I assume, the grit that they sell) is 1000 grit silicon carbide. The polish that I get from the Rock Shed is aluminum oxide powder that is something like 14,000 grit (it isn't specified, but this is the approximate particle size for AO polish). The cerium oxide polish that I get from Kingsley North is around 9000-13000 grit. You will normally see particle size for polishes measured in microns. 1 micron = 14,000 grit. The cerium oxide that I get is 1.5 to 2.5 microns. No matter how you measure it, 1000 grit silicon carbide seems completely unsuited for final stage polishing. Sometimes I use 1000 grit aluminum oxide as a pre-polish, but that is always followed by at least a week in actual polish. Tin oxide should work just fine.
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Post by susand24224 on Nov 8, 2021 0:32:30 GMT -5
Lots of things to say here, and more information would be helpful. If I ask something you've already answered, please forgive me--I skimmed through the thread maybe too quickly.
First, what are you tumbling? What is your mix of rocks? How hard are they? how varied are the sizes? Are they smooth or do they have holes/cracks, etc.?
Next, when you say you let them go for ten days, I assume you are talking about the polish stage (?) Are there any signs of polishing at all?
On filler: some people love plastic pellets, I personally detest them. They float around and escape, they trap grit, and you can't use the same pellets that you used in 90 grit in 120 grit, or 500, or polish. I much prefer ceramics, which someone mentioned. They are available in multiple sizes, which is crucial if you have some large rocks and not very many small ones. They are grit "carriers" and help grit and polish get into the indentations of larger rocks. Plus, you don't have to chase them around with a fish net in water to capture them, you just pick them out and they last quite awhile.
I have never used Nat. Geo. grit and/or polish, so can't comment on quality or amounts, or if it differs. In general, I use one tablespoon per pound when using a rotary. I haven't found much difference in quality in the silicon carbide grits from different places, but there is a world of difference in aluminum oxides. The Rockshed's is okay, but there are other aluminum oxides, such as Rapid Polish, that are much better. I like it better than cerium or tin oxide. With some rocks (most notably when I was using a rotary tumbler with obsidian and Apache Tears) you have to polish quite a bit longer--I've gone up to three weeks in polish.
The advice given to wash between each stage I 100% agree with. I do it every time, and I have a dedicated barrel for polish with both my vibe and the rotaries. I now only use the rotaries for 60/90 and very delicate rocks (either prone to fracturing or soft things like fluorite), but when I only had rotaries, the washing was a must.
On thing I should mention is to kind of ignore the directions that came with your tumblers. The person who wrote the instructions is not looking at your rocks, they are writing "in general." Look each rock over and make your own decision of whether it is ready for the next stage. I have little plastic drawers that rocks go in. Generally when I do a 60/90 run for a week in my largest tumbler, I'm lucky if one third of the rocks are ready for 120/220. The ones that are ready for the next stage go into the little plastic drawer where they stay until I have enough ready to start the vibe (or rotary) for the next stage. This means you have to have extra rough of suitable size and hardness to keep the 60/90 stage full enough, but with a little creativity this is easy--dollar stores sell little bags of rounded rocks, most large hardware stores sell some type of landscaping rock that is suitable for this, bust up a few pieces of quartz, or I'll send you a small flat rate box full of saw scraps, mostly agate if you'll pay the postage.
One other thing--I don't remember where I bought them, but I have several little leather covered paddles that you can put a bit of polish on and rub on the rocks to see if they will polish. This gives you a clue as to whether rocks should be in polish stage at all.
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denversue
starting to spend too much on rocks
Member since October 2021
Posts: 160
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Post by denversue on Nov 8, 2021 7:57:12 GMT -5
Wow, thanks for all the information! I am on my phone right now and will have to go to my computer to answer your questions.
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