axid200
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Post by axid200 on Jun 10, 2018 10:31:52 GMT -5
I'm wondering if anyone could give me some troubleshooting advice. I've searched trying to find this topic to see if it's been discussed before with no luck... I'm still learning and try not to be a bother with questions but I've hit a wall. Like most, I use a rotary and vibe tumbler in tandem. I have a lortone qt-66 rotary which is the double 6lb barrel model. I've had a batch in one barrel that just finished it's fourth week. It's mainly a mix of Montana moss agate and lake Superior agate with a few other random pieces all similar MOHs. This issue I've had the past several weeks is when I go to change the grit after 7 days I dump the barrel to find the bottom is just a clump of grit - like the water and grit never mixed and it just settled at the bottom. Here is what I am doing and what i've tried so far to help prevent that from happening: 2/3 to 3/4 full Water to bottom of top layer of rocks 60/90 grit 7 days tumbling, no stopping I've adjusted to add fill to make sure the level was correct. I've tried both adding grit first then water and water first then grit. As soon as the water/grit are in it goes back on the tumbler. I clean rocks each week. I layer small/fill, medium, then large when filling the barrel. For the week just starting today I tried no fill but instead using new rocks to bring level up. I also am now using 46/70 grit instead of the 60/90. I should also note that the other barrel is tumbling and has not had the same issue with the grit/water mixing and seems to be functioning normal. Any clear errors or red flags you see with my process? Thank you in advance for any advice you may have to offer
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Post by aDave on Jun 10, 2018 12:56:48 GMT -5
Hi axid200. Welcome to the forum. It would seem that there is no issue to your approach in terms of how you're filling your barrel with water and the amount of rocks. How much grit are you using? My first reaction (guess) is wondering how your mix of stone sizes are in the "problem" barrel. If stuff is too similarly sized, grinding may not be as efficient (in terms of hitting all surfaces) which, in turn, does not use up all the grit. You mentioned you "layer" different rock sizes; interesting concept, but I don't know if that's having negative impact or not. I happen to randomly put all of my rocks in the barrel when I load it. Perhaps try that? I'd also stick with adding grit after the rocks and water are added. I'm not so concerned you're finding grit at the bottom, as unused grit will settle as soon as you place the barrel upright. I'm simply looking at your problem of grit not being used up. I am also wondering what RPMs your barrels are turning at. I'm not sure that's an issue, as you mentioned one barrel seems to do OK. My QT66 is at about 30-31 RPMs, FWIW. Hope that helps a bit.
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axid200
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Member since May 2018
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Post by axid200 on Jun 10, 2018 13:03:35 GMT -5
Hi axid200. Welcome to the forum. It would seem that there is no issue to your approach in terms of how you're filling your barrel with water and the amount of rocks. How much grit are you using? My first reaction (guess) is wondering how your mix of stone sizes are in the "problem" barrel. If stuff is too similarly sized, grinding may not be as efficient (in terms of hitting all surfaces) which, in turn, does not use up all the grit. You mentioned you "layer" different rock sizes; interesting concept, but I don't know if that's having negative impact or not. I happen to randomly put all of my rocks in the barrel when I load it. Perhaps try that? I'd also stick with adding grit after the rocks and water are added. I'm not so concerned you're finding grit at the bottom, as unused grit will settle as soon as you place the barrel upright. I'm simply looking at your problem of grit not being used up. I am also wondering what RPMs your barrels are turning at. I'm not sure that's an issue, as you mentioned one barrel seems to do OK. My QT66 is at about 30-31 RPMs, FWIW. Hope that helps a bit. Hi aDave and thank you for your response! I am using 10 tablespoons- is that too much? My mix is teeny tiny up to about 2". I will check the RPMs and let you know. That's a good idea too. Wondering though if it's the amount of grit. Although up until this batch I haven't had any issues. That being said, I've only been running it for 3 months Thanks!
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Post by aDave on Jun 10, 2018 13:20:24 GMT -5
Hi aDave and thank you for your response! I am using 10 tablespoons- is that too much? My mix is teeny tiny up to about 2". I will check the RPMs and let you know. That's a good idea too. Wondering though if it's the amount of grit. Although up until this batch I haven't had any issues. That being said, I've only been running it for 3 months Thanks! I'm using about the same amount of grit in mine. I wouldn't necessarily call your mix tiny (2"), but if you have too much of your larger pieces and not enough smaller pieces to fill the gaps, you could end up with that grinding inefficiency I mentioned. I'm really inclined to think this is the issue with this barrel. You said you've never had this happen before, and things in this batch could be "off" just enough to cause the issue you're seeing. Unfortunately, this stuff, as you know is often trial and error. Absent learning your barrel RPM, I say to just tweak your load to see what happens. Interestingly, jamesp would often use a rock in his load that he referred to as "Thor's hammer." It was one rock that was a bit larger than everything else (say, a 3" rock in your 2" mix), just to help with the grind. I've tagged him here in the event he has more input.
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axid200
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Member since May 2018
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Post by axid200 on Jun 10, 2018 13:27:41 GMT -5
Hi aDave and thank you for your response! I am using 10 tablespoons- is that too much? My mix is teeny tiny up to about 2". I will check the RPMs and let you know. That's a good idea too. Wondering though if it's the amount of grit. Although up until this batch I haven't had any issues. That being said, I've only been running it for 3 months Thanks! I'm using about the same amount of grit in mine. I wouldn't necessarily call your mix tiny (2"), but if you have too much of your larger pieces and not enough smaller pieces to fill the gaps, you could end up with that grinding inefficiency I mentioned. I'm really inclined to think this is the issue with this barrel. You said you've never had this happen before, and things in this batch could be "off" just enough to cause the issue you're seeing. Unfortunately, this stuff, as you know is often trial and error. Absent learning your barrel RPM, I say to just tweak your load to see what happens. Interestingly, jamesp would often use a rock in his load that he referred to as "Thor's hammer." It was one rock that was a bit larger than everything else (say, a 3" rock in your 2" mix), just to help with the grind. I've tagged him here in the event he has more input. Oh sorry, I meant the mix is from very small (like less than 1/2") to up to about 2". I tried to be sure to use small mix rocks, and fill if needed, in every batch and of course some medium pieces. But definitely this batch has more larger pieces (maybe 6-8 2" pieces of Montana agate) then I've ever tumbled. Maybe that is it?
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axid200
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Member since May 2018
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Post by axid200 on Jun 10, 2018 13:41:14 GMT -5
Hi aDave and thank you for your response! I am using 10 tablespoons- is that too much? My mix is teeny tiny up to about 2". I will check the RPMs and let you know. That's a good idea too. Wondering though if it's the amount of grit. Although up until this batch I haven't had any issues. That being said, I've only been running it for 3 months Thanks! I'm using about the same amount of grit in mine. I wouldn't necessarily call your mix tiny (2"), but if you have too much of your larger pieces and not enough smaller pieces to fill the gaps, you could end up with that grinding inefficiency I mentioned. I'm really inclined to think this is the issue with this barrel. You said you've never had this happen before, and things in this batch could be "off" just enough to cause the issue you're seeing. Unfortunately, this stuff, as you know is often trial and error. Absent learning your barrel RPM, I say to just tweak your load to see what happens. Interestingly, jamesp would often use a rock in his load that he referred to as "Thor's hammer." It was one rock that was a bit larger than everything else (say, a 3" rock in your 2" mix), just to help with the grind. I've tagged him here in the event he has more input. I did an RPM check and I'm at 30RPM too
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Post by aDave on Jun 10, 2018 13:56:03 GMT -5
Oh sorry, I meant the mix is from very small (like less than 1/2") to up to about 2". I tried to be sure to use small mix rocks, and fill if needed, in every batch and of course some medium pieces. But definitely this batch has more larger pieces (maybe 6-8 2" pieces of Montana agate) then I've ever tumbled. Maybe that is it? You might want to think about pulling a few of those Montanas, IMHO. Again, it's just a guess, but maybe there are just too many of the larger pieces to get an efficient grind. It sounds like your mix of sizes is pretty good, but since this is the first time you've gone to that many big pieces, I'd look to deal with those first.
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axid200
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Post by axid200 on Jun 10, 2018 13:57:49 GMT -5
Oh sorry, I meant the mix is from very small (like less than 1/2") to up to about 2". I tried to be sure to use small mix rocks, and fill if needed, in every batch and of course some medium pieces. But definitely this batch has more larger pieces (maybe 6-8 2" pieces of Montana agate) then I've ever tumbled. Maybe that is it? You might want to think about pulling a few of those Montanas, IMHO. Again, it's just a guess, but maybe there are just too many of the larger pieces to get an efficient grind. It sounds like your mix of sizes is pretty good, but since this is the first time you've gone to that many big pieces, I'd look to deal with those first. Thanks! Honestly at this point it couldn't hurt and I'm running out of things I haven't tried. Lol!
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Post by aDave on Jun 10, 2018 14:05:19 GMT -5
axid200, please let us know how it works out. And thanks, you've reminded me that it's cleanout day. But, that's a good thing...I finish a polish stage today.
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jamesp
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Post by jamesp on Jun 10, 2018 14:14:50 GMT -5
I would add some slurry thickener like kitty litter or clay. Maybe 1 or 2 cups in a 6 pound barrel. It will thicken the water and help it carry/circulate the grit. Think 'suspended particles'. And heavier fluid, like people floating in the salt rich heavy water of Salt Lake. Like a rock floating on mercury.
60/90 does well in straight water. 46/70 begins to not circulate/mix in some cases with straight water 30 grit pretty much needs a slurry thickener 16 grit does need a slurry thickener
clay, clay based kitty litter, even potter's clay if wetted will work.
"For the week just starting today I tried no fill but instead using new rocks to bring level up. I also am now using 46/70 grit instead of the 60/90."
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Post by Jugglerguy on Jun 10, 2018 14:35:08 GMT -5
I would add some slurry thickener like kitty litter or clay. Maybe 1 or 2 cups in a 6 pound barrel. It will thicken the water and help it carry/circulate the grit. Think 'suspended particles'. And heavier fluid, like people floating in the salt rich heavy water of Salt Lake. Like a rock floating on mercury. 60/90 does well in straight water. 46/70 begins to not circulate/mix in some cases with straight water 30 grit pretty much needs a slurry thickener 16 grit does need a slurry thickener clay, clay based kitty litter, even potter's clay if wetted will work. "For the week just starting today I tried no fill but instead using new rocks to bring level up. I also am now using 46/70 grit instead of the 60/90." jamesp, I know that you use clay thickener and I don't, but I think you may have made a mistake in your suggestion. I have tried kitty litter on several occasions, and the reason I don't like it is because it makes the slurry too thick and it takes too long to rinse the rocks. You just suggested 1-2 CUPS of clay per six pound barrel. When I've tried kitty litter, I used about two TABLESPOONS and thought it made the slurry too thick. Surely, you don't mean two CUPS, but rather two TABLESPOONS, right? Two cups would nearly fill the barrel with clay.
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jamesp
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Post by jamesp on Jun 10, 2018 15:17:26 GMT -5
I would add some slurry thickener like kitty litter or clay. Maybe 1 or 2 cups in a 6 pound barrel. It will thicken the water and help it carry/circulate the grit. Think 'suspended particles'. And heavier fluid, like people floating in the salt rich heavy water of Salt Lake. Like a rock floating on mercury. 60/90 does well in straight water. 46/70 begins to not circulate/mix in some cases with straight water 30 grit pretty much needs a slurry thickener 16 grit does need a slurry thickener clay, clay based kitty litter, even potter's clay if wetted will work. "For the week just starting today I tried no fill but instead using new rocks to bring level up. I also am now using 46/70 grit instead of the 60/90." jamesp, I know that you use clay thickener and I don't, but I think you may have made a mistake in your suggestion. I have tried kitty litter on several occasions, and the reason I don't like it is because it makes the slurry too thick and it takes too long to rinse the rocks. You just suggested 1-2 CUPS of clay per six pound barrel. When I've tried kitty litter, I used about two TABLESPOONS and thought it made the slurry too thick. Surely, you don't mean two CUPS, but rather two TABLESPOONS, right? Two cups would nearly fill the barrel with clay. Thanks Rob. 2 cups should be a real over dose. I actually meant 2 scoops but my scoop is 2 tablespoons. My clay is half sand so 1 or 2 of these scoops works fine. Some kitty litter is 100% clay and does thicken a lot and 1 to 2 tablespoons may do the job.
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jamesp
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Post by jamesp on Jun 11, 2018 6:38:13 GMT -5
I often tumble 1.5" and 2" rocks with no smalls. Because I may not want small tumbles. The smalls do help circulate the grit and prevent such a fast wash down of the grit with all larger rocks. But I must use slurry thickener to circulate 30 and 46 grit(or larger of course) when running a batch of all larger rocks.
Referring to this statement - "For the week just starting today I tried no fill but instead using new rocks to bring level up."
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axid200
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Post by axid200 on Jun 11, 2018 6:39:24 GMT -5
I often tumble 1.5" and 2" rocks with no smalls. Because I may not want small tumbles. The smalls do help circulate the grit and prevent such a fast wash down of the grit with all larger rocks. But I must use slurry thickener to circulate 30 and 46 grit(or larger of course) when running a batch of all larger rocks. Referring to this statement - "For the week just starting today I tried no fill but instead using new rocks to bring level up." Sorry, I meant no pellets as fill. I just added more smaller and medium rocks
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axid200
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Post by axid200 on Jun 11, 2018 6:41:51 GMT -5
jamesp I will definitely try adding kitty litter next though. I had four seperate weeks at 60/90 that left a lot of unused grit on the bottom of the barrel. I just started 46/70 yesterday. What kind of kitty litter ? Are there certain ingredients I should be looking for? I'm headed out of town for a conference today but will pick some up when I am back. Thank you for your help!
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jamesp
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Post by jamesp on Jun 11, 2018 7:28:19 GMT -5
OK axid200, I use Georgia red clay. When it is dry and fluffy like talcum powder I use 1 to 2 cups, if wet and dense I use ~4 tablespoons. So, different clays act different ways. Covington Lapidary sells a California clay called Old Miser for this same issue being questioned on your thread. The folks on the forum seem to be having luck with kitty litter(fired clay). Usually the cheap kitty litter is fired clay, the expensive stuff is some kind of "smell good synthetic". Use cheap fired clay kitty litter, not the fancy smell good stuff. No guarantee that you are buying clay based, but it is the white/beige/grey stuff from back in the old days and the most common kitty litter. You may have to experiment with how much you add. I want you to end up with a medium milkshake consistency. You have to let your rotary run say 15 minutes and then check the consistency. Add to thicken, pour slurry off and add clean water to thin. It is just like making a roux, add flour/oil till the right consistency happens. Good luck.
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tkvancil
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Post by tkvancil on Jun 11, 2018 8:14:28 GMT -5
axid200 My two cents .... You mentioned pellets and rocks smaller than one half inch. IF those are plastic pellets they will slow down/cushion the load. IF you have too many too small rocks they can "hog the grit" also slowing down the grind. Plastic pellets do have a use in coarse grinding delicate rocks but generally are not useful with most mohs 7 material. Small rocks should be only one quarter of the load give or take a little. The larger rocks are likely not the problem. Over loading a barrel will cause grit to be left over. I always found my 6# barrels did best when closer to 2/3 rather than 3/4. Too full and there is not enough room for tumbling action. I always found the sixes hard to judge when filling due to the low profile. You can certainly try a thickener if you like, personally I don't like them. One more thing to account and adjust for IMHO. The bottom of top layer guideline for water never worked well for me. In a 6# barrel one cup of water is well below the top layer but is usually enough. You can also cut back to 8 tbs. of 46/70. I did an experiment some years ago and found that 8 is enough. It gets used up and removes a nearly identical amount of material as does 10. Hope some of this can be helpful.
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Post by gmitch067 on Jun 11, 2018 11:24:38 GMT -5
When I notice coarse grit accumulating at the bottom of my QT66/12 loads I add more kitty litter and extend my grind out to 10-12 days. For a 6 lb barrel I use about 1/2 cup kitty litter... unless I happen to be tumbling feldspar material... then I cut back a little. The debris ground off of feldspar material creates it's own natural slurry and could be the reason that some loads have less wasted grit than others. I use 46/70 grit in my coarse grind... The slurry thickener (kitty litter) is needed to keep the heavy grit in suspension (thanks jamesp !) The process and stone sizes you are using sounds good to me axid200 . Glenn
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jamesp
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Post by jamesp on Jun 11, 2018 11:33:50 GMT -5
When I notice coarse grit accumulating at the bottom of my QT66/12 loads I add more kitty litter and extend my grind out to 10-12 days. For a 6 lb barrel I use about 1/2 cup kitty litter... unless I happen to be tumbling feldspar material... then I cut back a little. I use 46/70 grit in my coarse grind... The slurry thickener (kitty litter) is needed to keep the heavy grit in suspension (thanks jamesp!) The process and stone sizes you are using sounds good to me axid200. Glenn I live in slurry country lol, Georgia clay has been an additive to suspensions from ink to mining operations for many years. If you want tumble delicate or big you best have a slurry strategy. When tumbling glass I use 3 different slurries. One or two in rotary and one in each different vibes. The problem with clay is it is variable. I have succeeded at tumbling fluorite(once) but never could find the correct slurry mix again.
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jamesp
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Post by jamesp on Jun 11, 2018 12:13:42 GMT -5
axid200 My two cents .... You mentioned pellets and rocks smaller than one half inch. IF those are plastic pellets they will slow down/cushion the load. IF you have too many too small rocks they can "hog the grit" also slowing down the grind. Plastic pellets do have a use in coarse grinding delicate rocks but generally are not useful with most mohs 7 material. Small rocks should be only one quarter of the load give or take a little. The larger rocks are likely not the problem. Over loading a barrel will cause grit to be left over. I always found my 6# barrels did best when closer to 2/3 rather than 3/4. Too full and there is not enough room for tumbling action. I always found the sixes hard to judge when filling due to the low profile. You can certainly try a thickener if you like, personally I don't like them. One more thing to account and adjust for IMHO. The bottom of top layer guideline for water never worked well for me. In a 6# barrel one cup of water is well below the top layer but is usually enough. You can also cut back to 8 tbs. of 46/70. I did an experiment some years ago and found that 8 is enough. It gets used up and removes a nearly identical amount of material as does 10. Hope some of this can be helpful. I built some short stubby barrels and never did like getting the rock level or water level correct in them. I ended up shelving them and glad I did. Better to have the barrel at least 1.5 times longer than the diameter for easier measuring.
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