jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Jan 20, 2020 15:36:37 GMT -5
Yes, if you look at them they break jamespFigured it brittle. I have been screening a 50 pound bag of 3/8" and smaller SiC. Stealing 10 and 60 grit. About all that is left is the 3/8" chunks. Time to figure out some kind of crusher make the 3/8" chunks smaller. Thinking about welding a 4x4x1 inch steel chunk big side down on the end of a 4' steel pipe and some elbow grease for a crusher. Maybe use a fire pit bowl mortar/pestle set up. I used to dread dumping SiC in the barrel as discussed above. Since getting that cheap SiC I don't care. Carbolon SC made by Washington Mills.
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whyofquartz
spending too much on rocks
So, Africa is smaller than I expected...
Member since December 2019
Posts: 316
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Post by whyofquartz on Jan 21, 2020 19:01:32 GMT -5
I need to get/build a bigger tumbler so I can play along at home. I also need to find a way to polish my Africa stone without diminishing it's unique characteristics. maybe a vibe tumbler running 220 on up?
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Post by HankRocks on Jan 30, 2020 19:09:55 GMT -5
1st Clean Out 1-30-2020 - 11 days Schedule here at home pushed this to 11 days instead of the normal 10 days. The large Crystal was definitely worn down a bit, still a ways to go Single point - start - 4.107 lbs (1863 grams) - first clean out - 3.97 lbs(1800 grams) for a about 3.4% loss (not a very good picture- was in a hurry) IMG_1006 by Findrocks, on Flickr As expected the added smaller broken crystals filler took a real grinding, starting at about 8 lbs and weighing at just over 6 lbs for almost a 25% loss! The combination of being crystal quartz and having the over sized hammer in there did the trick. Some of the quartz was ready to move on so I pulled 3 pounds out and had to add about 5 more fresh quartz. As you can see in the picture, all of the sharp broken edges and the face edges are gone. The hammer dished out a lot more than it took. IMG_1004 by Findrocks, on Flickr The Pea Gravel started at about 4 lbs and ended at about 2.75 pounds for an almost 31%loss. One big contributing factor here is that some of the Pea Gravel I use is very soft and goes to slurry very fast. Overall I think for the 2nd run I will drain off a bit of the slurry and add more filler during each of the 2 re-charges. I have noticed with tumbling quartz, the slurry seems lighter, not as dense as agate slurry. That doesn't make sense to me. Also noticed that when dry-caking a quartz slurry, the slurry takes a lot longer to settle out than agate slurry. Henry
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Benathema
has rocks in the head
God chased me down and made sure I knew He was real June 20, 2022. I've been on a Divine Mission.
Member since November 2019
Posts: 703
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Post by Benathema on Jan 30, 2020 19:16:32 GMT -5
NIIIIICE! Yea the little guys take a pounding... that's why I was kind of tripping about keeping barrels fed in the other thread. This is going to be cool. Thanks for weighing this. I know you're running a larger barrel. I find it interesting to see how the mass loss tracks with time. It's had me thinking about the overall shape of large rocks and what different surface area to mass ratios might do to change how much material is removed... given a particular hardness, of course. Looking forward to seeing more of this!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Jan 31, 2020 12:27:27 GMT -5
Fast results for 11 days Henry.
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Post by HankRocks on Feb 10, 2020 21:32:46 GMT -5
2nd Clean Out 2-10-2020 - 11 days
Kept the cycle at 11 days instead of the normal 10 days. The slurry was heavier at the end of this run. The large Crystal was definitely worn down a bit, still a ways to go .
Single point - start - 3.97 lbs (1800 grams) - 2nd clean out - 3.86 lbs(1750 grams) for a about 2.77% loss . This is % is less than the loss during the 1st run. Not sure why, it may be that the filler quartz was a bit more rough than in the first run. There also could have been a couple of small fractured flakes got knocked off in the first run.
The run continues to be a grinding mill for the filler quartz. Started with 8 pounds, added 1 pound at the 2nd re-charge. It was down to 6.5 pounds at clean out for a 27.7% loss. I pulled out another 3 pounds ready for next stage.
I think I am going to shorten the run to 10 days, the thickness of the slurry at clean out and no grit remaining tells me I can reduce the days after 3rd re-charge. Also noticed that the big crystal does not seem to be grinding as much on the top end. That is probably the case because the crystal cannot turn in the barrel and all of the heavy force is on the sides of it with more in-direct force on the top.
Sorry no pictures as I had to empty and get rock weight and barrel re-loaded before several errands today. I will have them next time.
Henry
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Post by RocksInNJ on Feb 11, 2020 1:23:58 GMT -5
Thanks for the update Hank and no worries about the pics. We all get busy at times. Looking forward to next weeks report.
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Fossilman
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Member since January 2009
Posts: 20,666
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Post by Fossilman on Feb 11, 2020 10:57:48 GMT -5
Great recipe and idea...… I usually tumble larger material with small material also, it helps out with the finished appearance!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 13, 2020 5:17:53 GMT -5
Henry, ever think about opening up at 3 days and check silicon carbide. I believe you will find the silicon carbide worn slap out after only 3.
I dump the whole load slurry and all in a white plastic tub and run water over it. Let the water overflow till the water clears up some. SiC will sink to bottom being so heavy. Remove rocks with tub full so any SiC stuck to rocks will wash off and sink. Pour water off and see how much silicon carbide is left. Guessing you won't find 2 teaspoons of silicon carbide. Whatever SiC is left can be put back in the barrel.
It will give you a good idea of clean out intervals. When a I ran smaller 1.5 pound rocks my SiC 30 or SiC 10 was gone in 2 to 3 days in a 6" barrel at 38 rpm.
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Post by HankRocks on Feb 13, 2020 5:43:54 GMT -5
Jim, I am doing 2 re-charges during the run, 1st at 3 days and 2nd at 6 days. It seems I may have mis-spoke as the time between the the 2nd re-charge and the clean out was 5 days on the first two runs. I usually go 4 days on my normal runs of Agate and Wood. Figure the extra time gets those rocks which are ready to move on to 600 a bit more grinding with the reduced size grit.
Also have observed that the Ark Crystal runs seem to break down the SiC a bit slower than Agate. At the first 3 day re-charge for the crystal there has been just a bit of grit in the barrel. None that I see at the 2nd re-charge. It makes sense as the filler rocks are getting smoother and have more surface to surface contact. I suppose if I really wanted to speed this process up I would use pre-tumbled(smoothed) agate. It's more SiC resistant and would grind the big guy quicker.
Just keep on learning here. Henry
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 13, 2020 7:23:40 GMT -5
That recharge rate is what has worked for me too Henry. Awesome. Not to be in a hurry, it is just wasting time and energy rolling rocks with no abrasives.
Funny you mention the difference between crystalline quartz and agate. I used glass once with a big rock. That was a joke. Big rock barely changed, and the glass shrunk in no time. The slowest hardest rock I ever tumbled is the coral from Florida. Gotta be like Mohs 7.5. Add Montana agate and coastal chert and Texas chert to that list. I use the common coral with the big rocks since it is so slow to wear. Tumble rounded. Plus it rarely has fractures or divots in it.
The last question in the equation is the shape of the smaller rocks. I like 1 to 1.5" corals for the smalls. But not sure if rounder or flatter shapes are optimum for grinding efficiency. Opinions ?
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Post by HankRocks on Feb 15, 2020 8:57:15 GMT -5
That recharge rate is what has worked for me too Henry. Awesome. Not to be in a hurry, it is just wasting time and energy rolling rocks with no abrasives. Funny you mention the difference between crystalline quartz and agate. I used glass once with a big rock. That was a joke. Big rock barely changed, and the glass shrunk in no time. The slowest hardest rock I ever tumbled is the coral from Florida. Gotta be like Mohs 7.5. Add Montana agate and coastal chert and Texas chert to that list. I use the common coral with the big rocks since it is so slow to wear. Tumble rounded. Plus it rarely has fractures or divots in it. The last question in the equation is the shape of the smaller rocks. I like 1 to 1.5" corals for the smalls. But not sure if rounder or flatter shapes are optimum for grinding efficiency. Opinions ? Been pondering the shape of the smalls a bit, round? or flat? I would say the rounder the better, get more of a continuous rolling contact between rocks. I suppose it also depends on what it is you are trying to do, grind the big rock or grind the smalls. In my case I keep pulling out the smalls and replacing with new rougher smalls so I am grinding both. I have over 6 pounds of nicely smoothed rock ready for next stage with 3 to 4 pounds coming with the next clean out. I think I am definitely going to do almost all future coarse runs with a large rock in the batch. Not near as large as the big crystal I am running now, maybe on the order of .5 to 1.5 pounds. I have 20-25 nice Rio's that will fill the bill perfectly. Also began taking some of the nicer Petrified Wood pieces in that size range and cutting a flat base on them before tumbling. That way when finished polishing they should be nice display specimens. If the large rocks are in the .5 to .75 pound range will probably run a couple in there figuring that the big to big contacts will be low and not create too much of an issue. That also depends on the rocks, on some the "dings" are more visible and others less so. All this supports my theory that there are very few "hard rules" in rock tumbling, a lot more general guidelines which can be "bend to fit". Henry
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jamesp
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Member since October 2012
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Post by jamesp on Feb 15, 2020 12:20:51 GMT -5
If I have the time to recharge every 2- 3 days I always run the .75 to 1.5 pound big rock every time HankRocks. If all the others are 1 to 2 inch tumbles. Experience is over 25 big rocks 1 to 2 pounds run with smaller stones. This is a fact: If you tumble all 3/4" say 15 to 20 gram agates by themselves it can take 3 months(12 weeks) to round them off *well. Add the 1 pound rock and they will be rounded *well in 1/2 the time(6 weeks). Add a 1.5+ pound rock and it can drop to 1/3(4 weeks). Drop down to 100% say 5 to 10 gram agates and it must take over 6 months to round them *well. Probably longer. Add the 2 pounder and they get done in 6 weeks. That is 4 times faster. 100% BB sized almandine garnets looked the same after 2 months running with no bigger rocks. Wasted time. The big rock difference is night/day. Always having to add 1 to 2 inch rocks because they shrink with the big rock bearing down. And faster recharges. And no instructions mention a big rock. So much for "hard rules" !
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 15, 2020 12:57:16 GMT -5
Most Rio's and coral could be run several .6 to .7 pound big rocks together without hardly any edge frosting if barrel was kept 80% and 38 rpm. Even when barrel was run 80% instead of 65%(without big rock) full I got the super fast grind with the 1 to 1.5 pounder added. Quiet/gentle too.
This was a great set up: 7 pound barrels with 6 inch ID. 60 rpm 80% fill 1 to 1.5 inch agates 1.25 to 1.75 pound roundish to oval big rock Medium clay slurry SiC 10 or 30 2 day recharges, 7 day complete clean out, 3 days on last recharge if running SiC 30. The SiC 10 I would reuse the leftovers.
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Benathema
has rocks in the head
God chased me down and made sure I knew He was real June 20, 2022. I've been on a Divine Mission.
Member since November 2019
Posts: 703
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Post by Benathema on Feb 15, 2020 14:26:43 GMT -5
Just from my little bit of experience, having the big stone in there is mind-blowing. I'm burning through my rough stash so fast I can barely keep up with the appetite of these barrels.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 16, 2020 12:24:36 GMT -5
Just from my little bit of experience, having the big stone in there is mind-blowing. I'm burning through my rough stash so fast I can barely keep up with the appetite of these barrels. Been saying it for years. If you want to get a lot of tumbles tumbled, add a big rock ! It increases the point load grinding forces instead of equally distributed light weight forces. Another way to increase grinding forces is by tumbling long stones like obsidian needles creating a situation similar to a rolling log jam with constantly shifting high leverage fulcrum points. obsidian needles RocksInNJ: "At every site where I have found more than random needles, there seems to be a general matrix with needle sizes ranging from hair-like to honkers of up to thirty inches; but please, feel free to come up with a theory of your own. Perhaps they were left by aliens or are some kind of weird communist plot."
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Post by knave on Feb 16, 2020 12:33:52 GMT -5
My very first tumble had a large quartz in it. We were pleasantly surprised by the fast results. What all this 6 week stuff? Dumb luck. Nice to know it’s a fact.
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Post by RocksInNJ on Feb 16, 2020 16:15:34 GMT -5
Just from my little bit of experience, having the big stone in there is mind-blowing. I'm burning through my rough stash so fast I can barely keep up with the appetite of these barrels. Been saying it for years. If you want to get a lot of tumbles tumbled, add a big rock ! It increases the point load grinding forces instead of equally distributed light weight forces. Another way to increase grinding forces is by tumbling long stones like obsidian needles creating a situation similar to a rolling log jam with constantly shifting high leverage fulcrum points. obsidian needles RocksInNJ : "At every site where I have found more than random needles, there seems to be a general matrix with needle sizes ranging from hair-like to honkers of up to thirty inches; but please, feel free to come up with a theory of your own. Perhaps they were left by aliens or are some kind of weird communist plot." What? No alien probe cracks? Surely you’re slacking. Sounds like a communist torture plot to me.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 16, 2020 20:26:38 GMT -5
My very first tumble had a large quartz in it. We were pleasantly surprised by the fast results. What all this 6 week stuff? Dumb luck. Nice to know it’s a fact. The Mohs 7 agates and woods will take a lot of abuse. The coral down this way could be tumbled together with mostly darn heavy 2 inch chunks with only about 25% smalls mixed in. Pretty much got fast grind times running a high percent these bigger tumbles. The coral is especially resistant to bruises. But had to run thickener sugar or add pea gravel to 85% fill in step 3 and 4 in rotary to avoid very slight frost spots.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Feb 16, 2020 20:28:35 GMT -5
Apparently aliens skid landed on obsidian needles at times. Had to pick them out of their arses RocksInNJ lol.
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