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Post by Mel on Oct 4, 2021 16:41:39 GMT -5
What's the best large capacity tumbler?
Looking to polish up some lemon (or bigger) sized rocks, but I need something capable of handling them. QT12 isn't cutting it.
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Post by manofglass on Oct 5, 2021 10:24:27 GMT -5
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hypodactylus
spending too much on rocks
Member since July 2021
Posts: 434
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Post by hypodactylus on Oct 5, 2021 11:49:38 GMT -5
What's wrong with the QT12? Mine seems to be able to handle rocks of that size.
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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 Oct 5, 2021 17:43:42 GMT -5
Like a bunch all at once, or just a few at a time?
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hypodactylus
spending too much on rocks
Member since July 2021
Posts: 434
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Post by hypodactylus on Oct 6, 2021 10:30:12 GMT -5
Like a bunch all at once, or just a few at a time? You can do a few larger rocks at a time in the QT12, mixed with other size rocks. If you want to do many extra large rocks at a time; you will need a bigger tumbler.
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Oct 6, 2021 15:12:40 GMT -5
I'm a Lortone gal for rotary tumblers, and I love my 40 lb barrel for doing the larger stuff. In fact, unless I'm working with soft or fragile rough, the 40 lb barrel is my default to start any batch. I have tumbled rocks up to the size of a large orange, and am planning my biggest one yet - close to a grapefruit. Once you start doing larger rocks, however, you'll need a LOT of smaller rocks and buffering media (I use large quartz aquarium gravel) so that they don't just smash against each other and bruise themselves. Only one large rock goes into such a batch, and the whole batch becomes mostly about getting that special rock polished. FYI - I'm not finding the 40 lb Lortone currently available, and they are a bit pricy, but I love the quality of Lortone, so that's still my recommendation. You might be able to pick up a used one, or wait until they're available again. Best wishes and happy tumbling.
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Post by Bob on Oct 6, 2021 15:58:48 GMT -5
What's wrong with the QT12? Mine seems to be able to handle rocks of that size. Totally agree, even though I also have larger barrels. I sometimes have 3-4 rocks of that size in the 12lb barrel.
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Post by Mel on Oct 15, 2021 17:58:29 GMT -5
What's wrong with the QT12? Mine seems to be able to handle rocks of that size. My mistake; those lemon sized ones are my *smallest* lately. I'd like to polish some I have that are about as a big as a mini football. My QT12 will take them, but I was finding they get would often get wedged sideways so I gave up.
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Post by Bob on Oct 16, 2021 13:21:27 GMT -5
I tumble a lot of large rocks. My experience has taught me this. Take the minimum interior distance, which is flat to flat inside of a barrel that is longer than it is wide. In a barrel that is wider than it is long, like the Lortone 6lb, it's the top to bottom distance inside that is shortest. Let's say the distance is 10". Obviously the rock has to be smaller than 10" or it won't tumble.
But how much clearance is really needed? 1/4"? 1/2" 1"? If I tumble rocks in that are 9.5" or more in a 10" place, I sometimes get jams, but otherwise it works. I think that's because my filler is typically 1/2" max quartz river gravel, and so at least one of those needs to pass with the rock to clear successfully, but I really don't know for sure because I can't see in there.
I have a large piece of granite that is football shaped. It will fit in my 40lb barrel with about 5/8" clearance. My theory is that the ends of it won't get ground much unless filler can get around them equally easy as it can everywhere else. It's been through about 4 weeks of rough grind. Sure enough, the sides are done, but the ends are getting smoothed only maybe half or less as fast. So I can do nothing to prevent this particular size/shape rock in that particular barrel from decreasing in diameter relative to it's length.
So in a way, I guess I am using a formula. (Max rock length) < (barrel min distance) + (length of rocks used as filler material)
However, that's in instances of where I've got one monster in the barrel and I can't risk anything else other than filler rocks to tumble with it or else I expect jams will occur.
A few days ago, I did a new 20lb barrel load similar to what I've done in the past. It has 3-4 pretty big ones in there, around apple-size. Then misc. jaspers and agates of all sizes up to lemon, and then some small filler too. So one might think all these big ones could jam up together somehow in there, because two of them together are more than the minimum distance in the barrel, but I don't think it ever happens because I've done these kinds of loads before and all go fine.
Somewhere I read once that special considerations only need to be used really when there is a rock in the barrel that exceeds 50% the minimum distance. I suppose that makes sense. But in actual practice, I'm probably not thinking too hard about this until a rock is 75% or more of that distance.
I have no way or writing it quantitatively by the numbers, but the more a given barrel load is taken up by very large (relative to barrel size) rocks, you learn that three things apply: 1) you must have few of them, maybe only 1, 2) the larger it or they are, the more the rest of the load should be only small filler (~.5") for proper grinding and least impact damage if more than one big rock, and 3) the fewer of in-between size rocks--maybe even none--that you want in there.
Others here may have different ways of going about that--this is only me.
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Post by Mel on Oct 16, 2021 21:26:43 GMT -5
Bob - Was it you that had the massive aventurine they'd been tumbling forever? Maybe it was Hank. I'm not worried about the fill (I have nearly unlimited access to all sizes of filler rocks and a solid supply of grit), but it seems silly to run multiple machines when I could use one large unit to do most of the work. Time will tell. Not to mention I have my flat lap ready to rock, and I'd like to tumble then cut & flat polish some display pieces.
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Post by Rockoonz on Oct 16, 2021 21:41:00 GMT -5
I have a couple 40 lb barrels as well, good for 2-3 softball sized or one bigger one in an otherwise normal load. The metal 15lb barrels with liners will also work better with larger stuff IMO. The QT12 barrels are too round inside, probably fine for later stages but not enough action for coarse.
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Post by HankRocks on Oct 17, 2021 6:51:54 GMT -5
Bob - Was it you that had the massive aventurine they'd been tumbling forever? Maybe it was Hank. I'm not worried about the fill (I have nearly unlimited access to all sizes of filler rocks and a solid supply of grit), but it seems silly to run multiple machines when I could use one large unit to do most of the work. Time will tell. Not to mention I have my flat lap ready to rock, and I'd like to tumble then cut & flat polish some display pieces. It was not me tumbling Aventurine, I had a large piece of Petrified wood and a large Quartz crystal. Both were tumbled in a Model B. I have considered getting a 20 pound tumbler. Do not really want to go down the weight-lifting, body building(did I mention back injuring?) exercise routine that is the cleanout for a 40 pounder.
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Post by Bob on Oct 18, 2021 11:14:43 GMT -5
Bob - Was it you that had the massive aventurine they'd been tumbling forever? Maybe it was Hank. I'm not worried about the fill (I have nearly unlimited access to all sizes of filler rocks and a solid supply of grit), but it seems silly to run multiple machines when I could use one large unit to do most of the work. Time will tell. Not to mention I have my flat lap ready to rock, and I'd like to tumble then cut & flat polish some display pieces. It was not me tumbling Aventurine, I had a large piece of Petrified wood and a large Quartz crystal. Both were tumbled in a Model B. I have considered getting a 20 pound tumbler. Do not really want to go down the weight-lifting, body building(did I mention back injuring?) exercise routine that is the cleanout for a 40 pounder. Yea, me on the aventurine piece. I've tumbled and am currently tumbling a lot of large rocks but don't have time to document or post about them here. Lifting that 40lb is indeed dangerous. I view it as a challenge, and some exercises I do in my life already prepare me for it, but loaded it feels like it's close to 100lbs and getting it up on the bench, which I have to do every 6 days, is something else. My reason for multiple tumblers (I have 4 but they hold 8-9 barrels depending), is merely for more production. If I had one monster barrel that weighed 150lbs, I could get by I suppose with one tumbler but the clean/recharge cycle would take probably an entire day. I prefer having a little bit almost each evening and spread out almost daily when I get off work. Currently: 40lb doing 50 grit 20 doing 80 20 doing 1,000 12 doing cerium ox 2nd week 12 doing 600 12 doing 220 12 doing 80 6 doing alum ox 1st week Normally I never go finer grit than 220 in a 20lb barrel, because after that the rocks are small enough that can go finer in a 12lb barrel. But, now and then like now, there is one rock so large that it will have to go all the way to polish in that 20lb barrel. It works fine, but cleaning a large barrel and lid liner so obsessively like I do for polish is much more work than a 12lb barrel. Btu I NEVER do a polish run in any barrel that didn't just prior do 1,000 or polish or burnish This really minimizes the chance of a stray grit particle getting in polish. Only once have I done a polish run in the 40lb barrel. Whew, that was 4 cups of polish! I'll never forget rinsing that many rocks after a polish run and seeing them all laid out. Dealing with that took about 1/2 day.
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Post by Mel on Oct 20, 2021 12:07:39 GMT -5
It was not me tumbling Aventurine, I had a large piece of Petrified wood and a large Quartz crystal. Both were tumbled in a Model B. I have considered getting a 20 pound tumbler. Do not really want to go down the weight-lifting, body building(did I mention back injuring?) exercise routine that is the cleanout for a 40 pounder. My reason for multiple tumblers (I have 4 but they hold 8-9 barrels depending), is merely for more production. If I had one monster barrel that weighed 150lbs, I could get by I suppose with one tumbler but the clean/recharge cycle would take probably an entire day. I prefer having a little bit almost each evening and spread out almost daily when I get off work. Currently: I think the same way! I have acquired another QT so now have 2 running 12 pound barrels, and 1 that's running the dual 6 pound barrels 24/7. Long term plan is get a 44 to get all my stage 1 done, and then split them among the QTs. My most recent rock hotspot finds come with a LOT of crud/rind. My thinking is that the metal barrel will hold up better over the long term for the roughest rocks and I can also go to a 46/70 mix to speed it up a little more. Thoughts?
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,681
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Post by Fossilman on Oct 20, 2021 13:53:55 GMT -5
I run an old Q12 and it does a great job on tumbling fist size and bigger material... I do two week cycles on each grit stage too..
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Post by Bob on Oct 20, 2021 23:06:48 GMT -5
Mel, yes the 40lb barrel is where everything except delicate stuff starts. One week in 50-60 grit in the 40 shows me a lot about the rock, what might play out next, or discard, or saw off part, etc. I love seeing the first week results after a nature found dirty rock getting its rind removed! Lots of excitement. Some disappointment too of course.
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