sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 5, 2018 19:26:33 GMT -5
I have two Lortone rotary tumblers, a 3A and 33B. Now and then, when dumping out the barrel, there will be a clump of thick gritty slurry and rocks stuck together at the bottom. It has happened on both tumblers. They are 3# barrels and I use 4 tablespoons of grit and fill the tumbler with water to the top rocks. It only happens once in a while though and I don't know why it happens.
Why does this happen..?
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Post by aDave on Dec 5, 2018 20:19:55 GMT -5
How long have you waited before dumping out the grit/slurry after shutting off the tumbler? If you have pulled the barrel and then rested it upright for any amount of time, all of the solids will settle to the bottom and cake some of your rocks.
That said, if you're finding you have an excessive amount of grit left over, your tumbling has not been efficient enough to break down the grit. It's a two way street - you need to find a balance between how much grit you have and the right rock mixture to make all of the grit "go away."
You might have to change your ratios of smalls versus large rough so the grit can be broken down properly. I'm using a larger tumbler than you, but all grit is pretty much gone when I've done my weekly cleanouts. That tells me I am getting the max out of the grit, and the balance of large to small material is good enough to break that stuff down.
As an aside, if you are speaking about the coarse grind, don't use anything more coarse that 60/90 in your tumbler. 46/70 won't be broken down properly as there isn't enough weight in the barrel to do so.
ETA: I'll lastly add that a barrel that holds more weight will be more efficient with the grinding process. I don't own a tumbler as small as yours, but there really isn't alot of weight in your barrels to help break down grit. FWIW, I started my tumbling routines with a 4 lb barrel. As soon as I stepped up to 6 lb barrels, I noticed a significant increase in how grit affected the rocks.
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 5, 2018 23:32:57 GMT -5
How long have you waited before dumping out the grit/slurry after shutting off the tumbler? If you have pulled the barrel and then rested it upright for any amount of time, all of the solids will settle to the bottom and cake some of your rocks. That said, if you're finding you have an excessive amount of grit left over, your tumbling has not been efficient enough to break down the grit. It's a two way street - you need to find a balance between how much grit you have and the right rock mixture to make all of the grit "go away." You might have to change your ratios of smalls versus large rough so the grit can be broken down properly. I'm using a larger tumbler than you, but all grit is pretty much gone when I've done my weekly cleanouts. That tells me I am getting the max out of the grit, and the balance of large to small material is good enough to break that stuff down. As an aside, if you are speaking about the coarse grind, don't use anything more coarse that 60/90 in your tumbler. 46/70 won't be broken down properly as there isn't enough weight in the barrel to do so. ETA: I'll lastly add that a barrel that holds more weight will be more efficient with the grinding process. I don't own a tumbler as small as yours, but there really isn't alot of weight in your barrels to help break down grit. FWIW, I started my tumbling routines with a 4 lb barrel. As soon as I stepped up to 6 lb barrels, I noticed a significant increase in how grit affected the rocks. Thanks Dave.We take the barrel off the tumbler and dump it right away so it isn't sitting any amount of time. You're right, when that happens the grit hasn't broke down well. I do have different size rocks combined with ceramic media in them. One thing I thought of was I believe the last two barrels that this happened, they were pretty full barrels, maybe 85% full. I'm wondering if this could be the reason it didn't get broken down.
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Post by aDave on Dec 5, 2018 23:49:52 GMT -5
Thanks Dave.We take the barrel off the tumbler and dump it right away so it isn't sitting any amount of time. You're right, when that happens the grit hasn't broke down well. I do have different size rocks combined with ceramic media in them. One thing I thought of was I believe the last two barrels that this happened, they were pretty full barrels, maybe 85% full. I'm wondering if this could be the reason it didn't get broken down. Could have been too full which might have inhibited the tumbling action. Tough call, but based upon what you mentioned, that would be my first guess. You might want to try cutting back on the volume a bit - perhaps 2/3rds to 3/4. If your barrel is packed too tightly, tumbling won't occur. I think cutting back will cure your problem. I'd be surprised if it doesn't.
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Post by grumpybill on Dec 6, 2018 7:00:06 GMT -5
I give the barrels a good shake, end to end, every day or two during the run.
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Fossilman
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Member since January 2009
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Post by Fossilman on Dec 6, 2018 11:13:18 GMT -5
I say to much grit and not enough water....
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Post by johnjsgems on Dec 6, 2018 11:33:18 GMT -5
Yes, 3/4 full and 3 tbs. grit.
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 6, 2018 17:45:30 GMT -5
Thanks for all the help guys. I'm going to put it to use next change and check it out. I think I have a handle on it now, we'll see.
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kskid
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Member since July 2014
Posts: 98
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Post by kskid on Dec 6, 2018 22:27:24 GMT -5
I say to much grit and not enough water.... I agree with fossilman. One other thought though, since it only happens occasionally. I mix a variety of found rocks all together. Every once in a while a very soft rock will sneak it's way into a barrel. As the soft rock is ground away, it significantly thickens the slurry - sometimes even into a paste if I don't hear it in time. If you just eyeball hardness (like me), this may be a factor.
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 21, 2018 11:53:20 GMT -5
..
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Post by manofglass on Dec 21, 2018 12:36:43 GMT -5
To much cat litter
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 21, 2018 15:15:34 GMT -5
It's aggravating. It happened again with two tumblers. I'm no seasoned expert but I've been at this a year with good results in the past. It's something that just started happening. Lortone, 3# tumbler, No kitty litter, 3/4 full tumbler, all agates, different sizes, three tbs #60 grit, water filled to bottom of the rocks on top of tumbler, one day in tumbler. I checked 24 hours after first starting. Everything was clumped at the bottom.
Yesterday it happened again in a different barrel with a mix of ceramic media, free form flat cabs, 3 tbs #2 grit. In 24 hours they were clumped. Now this barrel was a mix of rocks with different hardness so it could be that. I really am doubtful though because it was only 24 hours in, not much time for a softer stone to foul the mixture. Another thing is that it happened in the barrel that contained nothing but agate.
I don't get it.....
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Post by grumpybill on Dec 21, 2018 19:38:23 GMT -5
Are the tumblers sitting level?
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 22, 2018 13:24:25 GMT -5
Are the tumblers sitting level? I thought they were Bill because they're on a shelf but to be sure I went out and checked. It's level so that's not it. Good thinking though.
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Post by aDave on Dec 22, 2018 21:08:20 GMT -5
It's aggravating. It happened again with two tumblers. I'm no seasoned expert but I've been at this a year with good results in the past. It's something that just started happening. Lortone, 3# tumbler, No kitty litter, 3/4 full tumbler, all agates, different sizes, three tbs #60 grit, water filled to bottom of the rocks on top of tumbler, one day in tumbler. I checked 24 hours after first starting. Everything was clumped at the bottom. Yesterday it happened again in a different barrel with a mix of ceramic media, free form flat cabs, 3 tbs #2 grit. In 24 hours they were clumped. Now this barrel was a mix of rocks with different hardness so it could be that. I really am doubtful though because it was only 24 hours in, not much time for a softer stone to foul the mixture. Another thing is that it happened in the barrel that contained nothing but agate. I don't get it..... I'm going to take a wild guess on this. Don't know how long this will be, so please bear with it, and I'll apologize in advance for length. It wasn't until your most recent post that I saw you discovered caking after 24 hours. I gathered you discovered this when checking the barrel after that time period. To a small degree, I'm not surprised at what you're finding in such a short time period. To go further, I'm thinking caking would be less prevalent if the barrel was stopped or checked much further down the road. I'll try to explain my thought process. First, let me say, I think you're right on track with what you've written about your tumbling regimen. I've got no concerns at all about what you're doing. Grit size is correct, barrel fill is correct, and water level is where it should be. I think you're OK here. That's just my humble opinion. Where I think the issue might be is your "early" check of your tumble (24 hours) which is seemingly telling you that you have a "caking" problem. My thoughts are this: You started your coarse grind, and 24 hours later you pulled the barrel to see what is going on. At that point, IMHO, it makes no difference in how fast you can get the barrel open, but the fact that it sits flat after such a short period of starting your grind, you have alot of solids (grit and sediment) that can immediately settle to the bottom of your barrel. After 24 hours, you will still have a bunch of unused grit, and you will have some sediment from the grinding of the rocks. I'd tend to think this might add to what you think is a caking problem. I don't know why you're checking after 24 hours. If you have been tumbling stuff that you are comfortable with no overpressure, then there's really no reason to open up the barrel at all. I usually throw my rocks into coarse stage, and I am not opening the barrel until I'm ready to do a cleanout. Blowouts are not a concern of mine. I'd humbly recommend this: If you start up your coarse grind, and you hear rocks tumbling, let them go for a number of days before checking them. Moreover, if you have a particular comfort level, don't check them until you are ready to do a cleanout and inspection. The key is listening to your tumbler. If you start it up, and rocks sound like they're rolling, then you shouldn't have a caking issue. I'm beginning to think that your caking problem is simply related to you pulling the barrel after 24 hours. When you do so, all of the solids immediately settle, thus making your cake problem. If you are not comfortable in letting stuff go for a week without checking, start with just a few days. Frankly, I'm thinking you're not allowing enough time for grit breakdown which would alleviate what you're seeing after a 24 hour check. Hope this makes some sense. Short story...let your barrel go longer before you check it.
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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 Dec 22, 2018 22:07:49 GMT -5
I agree. Let the tumbler work. For hard stones, in stage 1, the course stage, I use the 3/4 rock load with water to just below the top layer of rocks, about 1 to 1.5 tbs of 60-90 grit per pound of rocks, balanced load with some balanced ceramic media. I run this for 10 days and then dump the load. Everything is well coated with slurry and no visible grit. I wash everything off, toss out the old slurry, and separate the rocks that tell me they are ready to go to step 2 from those that need another round of step 1 with new grit. I have never experienced caking. I think three quarters is the fullest you should go in filling your barrel for good tumbling action. I can tell from the sound of my tumbler that the rocks are tumbling and I don't open the barrel until the end of the 10 day cycle. Lastly, be patient and pay attention to what the rocks are showing you before proceeding to the next stage.
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kskid
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Member since July 2014
Posts: 98
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Post by kskid on Dec 22, 2018 23:16:11 GMT -5
When you say, "everything was clumped at the bottom..." does that mean when you removed the lid everything, the entire content, was a big wad of rock and wet clay stuck inside the barrel
or
you removed the lid, poured out the liquid & loose rock, and found a clump of everything still stuck to the inside bottom of the barrel?
Not being a wise guy; just clarifying the clues.
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Wooferhound
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Lortone QT66 and 3A
Member since December 2016
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Post by Wooferhound on Dec 23, 2018 4:16:08 GMT -5
I wouldn't use any Ceramic Media in a stage 1 Tumble.
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sactorick
having dreams about rocks
gemfield
Member since October 2017
Posts: 67
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Post by sactorick on Dec 23, 2018 8:10:46 GMT -5
When you say, " everything was clumped at the bottom..." does that mean when you removed the lid everything, the entire content, was a big wad of rock and wet clay stuck inside the barrel or you removed the lid, poured out the liquid & loose rock, and found a clump of everything still stuck to the inside bottom of the barrel? Not being a wise guy; just clarifying the clues. Thanks guys, I appreciate the input. aDave and gatorflash, thank you for the well thought out responses to this. The reason I checked the last two barrels 24 hours after I put them in was because I had experienced this clumping effect after running the tumbler for a week and I wanted to make sure it wasn't happening again. I normally load them up and run for 7 days before checking. Also the last time I made sure the barrel didn't sit flat after I loaded it. It went straight on the tumbler to start and right to checking it out when I took it off. Another thing, you can hear the rocks tumbling inside because when this happens, it's the bottom inch to inch and a half that's clumped. The mixture that isn't clumped is watery as the grit is all caked at the bottom with smaller rocks and media. It's perplexing as it doesn't happen all the time and I'm following basic tumbling instructions or standards. kskid... The caking is at the bottom inch to inch and a half. The top rocks are tumbling in a watery mix as the grit is caked at the bottom with small rocks and/or ceramic media. wolferhound.... I agree. I started one batch in grit#2 as they were flat preformed cabs and I added much ceramic media so the flat cabs wouldn't stick together. It was mostly ceramic and grit at the bottom of that one. The other barrel was agates of different sizes. I put that in grit #1 with NO ceramic. I never use ceramic or plastic in step one either. I'll use some aquarium gravel I get at walmart if I need it. I appreciate the help. I don't feel I'm straying too far and it's not like this happens every time. I also don't think it could be the grit. It must be something I'm doing....... Thanks!
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pizzano
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Member since February 2018
Posts: 1,390
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Post by pizzano on Dec 23, 2018 11:25:15 GMT -5
I just spotted this thread........sorry for the late response.......!
After reading each response and the responses to responses, no one has asked what type of stones are being tumbled......?
The OP has mentioned he has mixed hardness and the use of ceramics.....now even ceramic residual mixed within the grit mud settlings after 24hrs.......quite odd...!
The only time I've ever seen a "mud" build-up settle at the bottom of the 3lb rotary barrels (after such a short period of time) has been when stone types of mohs 4 or less hardness were mixed with harder mohs 6/7 types.......experienced this with material I had collected from Opal Mnt. not realizing exactly what I had collected and tried to keep safe the softer common opal that was imbedded within the harder matrix. It worked, but the "mud" slurry it developed became a problem and had to be thinned out quite often......this was during the 60/90 sic cycles...........I've never had ceramics breakdown that rapidly (24hr period) regardless of the type of stone they have been mixed with during 60/90 cycles.......?
It only takes a few a few softer stones (size plays a part as well) mixed with 60/90 sic along with mohs 7/8 agates or jaspers, to quickly develop a "mud" from residual break-down of the softer stones.......that's why it is recommended to rotary tumble like hardness stones together. Otherwise, unless intended, an unwanted "slurry" can develop, inhibiting the effectiveness of the grit and stone rotating action.......this can be a good thing if monitored and thinned out frequently, but in the OP's case, it appears to be unwanted.
Just my nickels worth of observation here........!
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