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Slurry
May 2, 2016 21:00:50 GMT -5
Post by spiceman on May 2, 2016 21:00:50 GMT -5
Still learning...maybe forever. OK, on the slurry. It seems that if I tumble hard rocks I.e. Agates, Quartz.... I get very little if any slurry. In that case does slurry come from the tumble rocks? If so, the little pieces of flint I find is a bad choice of tumble rocks? They are about as big as a pencil eraser and smooth? Then on stage 2 the slurry is less and the same with stage 3&4? Where does the slurry come from? So many questions because sometimes my slurry is good and others it very little or nothing. Any help is good for me. Thank you.
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Post by Jugglerguy on May 2, 2016 21:13:22 GMT -5
Slurry is rock dust, water, grit and anything else you added with your rocks. I find that soft rocks produce a thick slurry because they wear away easily. When I tumble Petoskey stones (MOHs 3), I get pudding like slurry in three days. Agates produces a thinner slurry as you noted because it takes longer to grind away because it's so much harder. I don't worry about it. If the grit is used up, then it did its job. I'd only worry if there was a bunch of grit left in the tumbler after a week.
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Intheswamp
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Member since September 2015
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Post by Intheswamp on May 3, 2016 6:47:52 GMT -5
Follow Rob's lead...he's spot on.
Remember, too, that the 1st (coarse) stage is the most aggressive stage that uses some rock-eating, sharp grit that is going to grind off a lot of rock...fast. The coarse grit is for forming and shaping the rock smooth. So, you should see the most slurry during the the coarse stage. As you do clean-outs and same-size grit replacements during the coarse stage you will probably see a thinner slurry develop (especially after the very 1st tumble)...I think this is due to the first grind taking off the "peeling" of the rock...the old, weather-beaten outside of the rock that has been possibly weakened by nature. Naturally the "peeling" would apply mostly to natural river/creek rocks rather than crushed rock which will have fresh sides to them. But, in the case of crushed rock you will have sharper, more fragile corners and edges that will get knocked off and ground down to dust fairly quickly, so even crushed rock should generate a faster slurry during the first tumble or so.
As you advance to smaller grits they become less aggressive in regards to grinding the rocks. The progressively smaller grits are used to remove scratches that the previous size grits left on the rocks...this is basically what we call "polishing" The finer grits grind off very, very small amounts of rock compared to the coarse grit...thus creating a much smaller amount of slurry during these more fine stages.
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Deleted
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Post by Deleted on May 3, 2016 15:53:52 GMT -5
jamesp sees value in starting with slurry. He adds clay. Different clays perform differently. I'll let him add more. I plan to add kitty litter for instant slurry. Hopefully it's a type of clay that is beneficial.
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jamesp
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Post by jamesp on May 3, 2016 16:17:54 GMT -5
jamesp sees value in starting with slurry. He adds clay. Different clays perform differently. I'll let him add more. I plan to add kitty litter for instant slurry. Hopefully it's a type of clay that is beneficial. Yes. I use milk shake consistency at start and all the way through coarse grind. Adding Georgia red clay from the start. Reasons: Helps pick up and circulate heavy 30 SiC grit, too avoid slurry cake. Protects delicate tumbles and larger rocks from crashing. I seem to get more rubbing and wear when rocks are somewhat stuck together. www.littleredstore.com/making-perfect-slurries.html
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Post by Jugglerguy on May 3, 2016 16:55:01 GMT -5
jamesp sees value in starting with slurry. He adds clay. Different clays perform differently. I'll let him add more. I plan to add kitty litter for instant slurry. Hopefully it's a type of clay that is beneficial. Yes. I use milk shake consistency at start and all the way through coarse grind. Adding Georgia red clay from the start. Reasons: Helps pick up and circulate heavy 30 SiC grit, too avoid slurry cake. Protects delicate tumbles and larger rocks from crashing. I seem to get more rubbing and wear when rocks are somewhat stuck together. www.littleredstore.com/making-perfect-slurries.html James, this is where you and I do things differently. I'm not sure who is right. I do not add anything to create a thick slurry. Any thickness is developed by rock wearing away during the week. I would love to speed up my rough grind stage, but I'm not yet convinced that adding thickeners will accomplish that. tkvancil's experiment isn't exactly the same as adding clay or other thickeners, but it shows that starting with fresh water and grit is either slightly better or at least no worse than recharging. I read just the rotary section of your link which says nothing about adding thickeners. It does say that the end slurry should be about the same thickness as thin pancake batter. Many of my slurries are not quite that thick. jamesp, you are using 30 grit, while I'm using 46/70 and I used to use 60/90. I wonder if that makes a difference. The one place that I do agree with you is that a thick slurry from the beginning must give more cushion to delicate rocks. However, most rocks are not all that delicate. I just wonder how it can cushion and at the same time grind better.
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jamesp
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Member since October 2012
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Post by jamesp on May 3, 2016 18:04:54 GMT -5
Yes. I use milk shake consistency at start and all the way through coarse grind. Adding Georgia red clay from the start. Reasons: Helps pick up and circulate heavy 30 SiC grit, too avoid slurry cake. Protects delicate tumbles and larger rocks from crashing. I seem to get more rubbing and wear when rocks are somewhat stuck together. www.littleredstore.com/making-perfect-slurries.html James, this is where you and I do things differently. I'm not sure who is right. I do not add anything to create a thick slurry. Any thickness is developed by rock wearing away during the week. I would love to speed up my rough grind stage, but I'm not yet convinced that adding thickeners will accomplish that. tkvancil's experiment isn't exactly the same as adding clay or other thickeners, but it shows that starting with fresh water and grit is either slightly better or at least no worse than recharging. I read just the rotary section of your link which says nothing about adding thickeners. It does say that the end slurry should be about the same thickness as thin pancake batter. Many of my slurries are not quite that thick. jamesp, you are using 30 grit, while I'm using 46/70 and I used to use 60/90. I wonder if that makes a difference. The one place that I do agree with you is that a thick slurry from the beginning must give more cushion to delicate rocks. However, most rocks are not all that delicate. I just wonder how it can cushion and at the same time grind better. stonemaster499 was the one that talked me into using 30 grit and jumpstarting it with thickener. He owned a commercial tumbling operation in Madagascar. The link mentions a thick slurry after 7 days. Curious if more grinding happens the first half or the second half of those 7 days. I have run 30 grit in clean water and had 30 grit after 5 days with no slurry. It was washing down. Certain that is not good. Usually have no 30 grit after day 4 doing milkshake consistency at start. 30 grit plenty big enough to see and feel. Added thickener is precisely measured. Too thick is not good either. PVC barrels are loud and the thicker slurry makes a real rubbing sound instead of a clanking sound. I figure quicker grit breakdown means better grinding. Lots of ways to skin the cat. Especially in tumbling hobby. I know rotary tumbler companies suggest 60/90 or 80 grit. Perhaps they are concerned about average Joe adding thickeners needed to circulate a 30 grit, or straight 46.
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Slurry
May 4, 2016 10:39:27 GMT -5
Post by spiceman on May 4, 2016 10:39:27 GMT -5
Good to get responses, so far I have learned lots about the slurry. Each and everyone will be tried and find the one that works for me. Maybe the think tto the problem Maybe using parts of all the postings to come up with the best results. Please don't stop replying because everyones idea is great, even if it is same as another posting.
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