DocMcCoy
off to a rocking start
Member since January 2021
Posts: 4
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Post by DocMcCoy on Jan 15, 2021 14:49:54 GMT -5
Hello everyone, I just got into rock tumbling and have two batches going right now in the rough stage. I like to understand the underlying principles of things and then use that knowledge to guide experimentation. Today's contemplation is on using small ceramics in the rough stage vs no ceramics. For context, I have the harbor freight dual 3# rotary tumbler.
The question I'd like to answer is: How do the stones vary when rough tumbled with and without filler. My thinking is that no filler will focus on the edges initially and eventually get to the concave portions of the stones in a few weeks. When using filler, I think the concave portions will start to get smoothed earlier on potentially yielding smooth concave portions of the stone with the edges more intact. What is y'all's experience in stone shape vs +/- media in the rough stage?
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 15, 2021 15:04:43 GMT -5
I prefer to use lots of little rocks, called "Smalls" to fill out a Stage 1 tumble. More different sizes and usually free.
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Post by HankRocks on Jan 15, 2021 18:24:09 GMT -5
I prefer to use lots of little rocks, called "Smalls" to fill out a Stage 1 tumble. More different sizes and usually free. ....key word there being "free"!
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reeniebeany
starting to spend too much on rocks
Rotary Only
Member since January 2020
Posts: 125
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Post by reeniebeany on Jan 15, 2021 18:38:38 GMT -5
Is there any intrinsic difference between using Pea Gravel vs. ceramic media? We got a load of pea gravel for drainage stuff. The batch we got had stuff mostly smaller than a pea, a good portion is one step off coarse sand, but it is all rounded, not sharp. I screened some out some of the bigger stuff to try. I also collect small stuff from the yard and driveway gravel, and have some of the mixed pebbles from the Dollar store.
Is there a standard ratio of sizes we should aim for? 1/3 tiny 1/3 small 1/3 fashion rocks? Do you use the same combo of sizes in both rotary and vibratory?
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Post by rmf on Jan 15, 2021 21:06:15 GMT -5
I think if you crack the rock with a hammer you will get 15% small (-1/2") and you get an assortment of sizes. If you need more smalls add pea gravel which I would assume is quartz, agate, jasper or chert/Flint. It is $6 for 40pound bag vs ceramics which cost more. you probably do not want to get over 33% fines but what ever works based on what you are tumbling. I like about 25% but your mileage may vary
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 15, 2021 21:18:21 GMT -5
----------------- When using filler, I think the concave portions will start to get smoothed earlier on potentially yielding smooth concave portions of the stone with the edges more intact. -----------------
Yes , adding Smalls to your Stage 1 will improve all your Tumbles by helping to smooth out the recessed areas.
----------------- Is there any intrinsic difference between using Pea Gravel vs. ceramic media? We got a load of pea gravel for drainage stuff. The batch we got had stuff mostly smaller than a pea, a good portion is one step off coarse sand, but it is all rounded, not sharp. I screened some out some of the bigger stuff to try. I also collect small stuff from the yard and driveway gravel, and have some of the mixed pebbles from the Dollar store. -----------------
Any kind of small sized stone, the harder the better, will help to improve to overall shape of your rocks. In Stage 1 you don't need to worry about anything you add Round or sharp just needs to be very hard material. I use all kinds of rocks to be Smalls including Reject Rocks, Glass, Marbles, leftover chips from breaking up larger rocks. I have a small river nearby that has the greatest little pebble banks that I fill a bucket with. I even add recovered dried slurry to my stage 1 tumbles.
----------------- Is there a standard ratio of sizes we should aim for? 1/3 tiny 1/3 small 1/3 fashion rocks? -----------------
All the sizes you can add that are smaller than your Target Stones. I'm normally adding about 1/4 Smalls and 3/4 Target Stones.
----------------- Do you use the same combo of sizes in both rotary and vibratory? -----------------
I only have a Rotary so I can't answer this.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 15, 2021 21:21:09 GMT -5
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jlcochran42
starting to shine!
Member since July 2020
Posts: 29
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Post by jlcochran42 on Jan 15, 2021 23:00:03 GMT -5
I prefer to use lots of little rocks, called "Smalls" to fill out a Stage 1 tumble. More different sizes and usually free. I just threw a lot of misfits into a barrel with smalls to see what I get out of it.
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reeniebeany
starting to spend too much on rocks
Rotary Only
Member since January 2020
Posts: 125
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Post by reeniebeany on Jan 16, 2021 16:35:35 GMT -5
I think if you crack the rock with a hammer you will get 15% small (-1/2") and you get an assortment of sizes. If you need more smalls add pea gravel which I would assume is quartz, agate, jasper or chert/Flint. It is $6 for 40pound bag vs ceramics which cost more. you probably do not want to get over 33% fines but what ever works based on what you are tumbling. I like about 25% but your mileage may vary We got 8 tons of the pea gravel so it is essentially free in the amount I am going to use. I also have a few tons of 5/8" minus to pull from. I usually put rounded smalls in with round target rocks and crunchy smalls in with the bigger crunchy rocks that are picked out of the 2" crushed clear stone we are using for driveways and stuff. I haven't cracked any rocks yet, but I might try that with some of the ones that are nice color but poor shapes. Do irregular, crunchy shaped rocks need more smalls than already rounded river type rocks?
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Post by rmf on Jan 16, 2021 16:49:18 GMT -5
Yeah! 8 tons of pea gravel Barely enough for any tumbler:)
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Jan 17, 2021 9:39:11 GMT -5
Doc - Welcome to the party! It is a great bunch of folks I must tell you. Here is a link to a book about rock tumbling. It will answer all your questions about everything rock tumbling. You can get a paper version or a version to download on your computer. I give a copy to my grandkids when they start getting into tumbling and it has helped them greatly. rocktumbler.com/book.shtmlI use media made just for rock tumbling is ceramic, SiC, in a mix of small and medium sizes. I use it in every stage. Here is some info about it. rocktumbler.com/media.shtml
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Post by greig on Jan 17, 2021 23:40:21 GMT -5
I try to avoid ceramic media in stage 1 & 2 because I am cheap. Those grits wear down the ceramics pretty quick. Instead, I add enough rock so this isn't required. ie. for most types of rock, the media is to top up your barrel to 1/2-3/4 full, (assuming you have different sizes of rock already in your tumble). I only add media in these stages if the rock is finicky (eg. feldspar - chips easy).
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DocMcCoy
off to a rocking start
Member since January 2021
Posts: 4
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Post by DocMcCoy on Jan 18, 2021 22:19:13 GMT -5
Thanks for all of y'all's input. I got a 5 gal bucket of 3/8" granite for my small filler rock. I'll see how smooth and small those get while in the rough stage and may make dedicated batches of granite for each grit (since I have 40# of it now).
I'll also get the book next month when the fun money resets.
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Post by Toad on Jan 19, 2021 11:54:41 GMT -5
I use quartz pea gravel from Walmart. Hard enough that it doesn’t disappear fast. The rest of the tumbler is filled with a few big but mostly medium chunks.
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dshanpnw
freely admits to licking rocks
Member since December 2020
Posts: 884
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Post by dshanpnw on Jan 24, 2021 15:13:59 GMT -5
Hello DocMcCoy and everyone, I try to fill the barrel with a mix of sizes, small to large, large being about 1 1/2 inches. I'm thinking having different shapes and sizes the edges work their way into every nook and cranny almost the same as other fillers. I just stick with ceramic media for now if I use media. It's what I read about using before I started. Ceramic media or other media would help to cushion the softer more precious materials like Greig stated.
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polaszko
having dreams about rocks
Member since August 2020
Posts: 58
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Post by polaszko on Jan 25, 2021 8:40:46 GMT -5
I'm joining discussion with granite. As greig I prefer cheap and effective solutions. Simply - if you hammer jasper, flint or anything to pieces you'll get cracked stones. It isn't big issue, because they are small at the end, but still avoiding cracking is my priority. I use hammered granite, cutted rubber (from car tube), and plastic beeds. Tumbling is slower, because grit is used to carve granite and plastic, but rocks carve more evenly and I avoid cracking.
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DocMcCoy
off to a rocking start
Member since January 2021
Posts: 4
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Post by DocMcCoy on Jan 25, 2021 10:21:27 GMT -5
I'm joining discussion with granite. As greig I prefer cheap and effective solutions. Simply - if you hammer jasper, flint or anything to pieces you'll get cracked stones. It isn't big issue, because they are small at the end, but still avoiding cracking is my priority. I use hammered granite, cutted rubber (from car tube), and plastic beeds. Tumbling is slower, because grit is used to carve granite and plastic, but rocks carve more evenly and I avoid cracking. Thanks for the info. So with the filler in the barrel, you notice the rocks maintain their shape more and are ground down more evenly?
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polaszko
having dreams about rocks
Member since August 2020
Posts: 58
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Post by polaszko on Jan 28, 2021 4:34:22 GMT -5
I'm joining discussion with granite. As greig I prefer cheap and effective solutions. Simply - if you hammer jasper, flint or anything to pieces you'll get cracked stones. It isn't big issue, because they are small at the end, but still avoiding cracking is my priority. I use hammered granite, cutted rubber (from car tube), and plastic beeds. Tumbling is slower, because grit is used to carve granite and plastic, but rocks carve more evenly and I avoid cracking. Thanks for the info. So with the filler in the barrel, you notice the rocks maintain their shape more and are ground down more evenly? Yeah - sometimes rocks have concave surfaces. That surfaces will carve better with small rocks - if you don't want to hammer nice rocks like jaspers or agates you should use filler.
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felinefred68
off to a rocking start
Member since January 2021
Posts: 4
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Post by felinefred68 on Jan 28, 2021 10:40:36 GMT -5
I am on only my second set of rocks being tumbled and I added the ceramic pellets to them. The rocks are all small baby-fist sized and 5 of them. I have a NatGeo pro tumbler. Anyway, the second cycle I kept getting an error message. I took the ceramic pellets out, decreased the water, and it is running smoothly now.
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