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Post by Jugglerguy on Sept 4, 2013 21:26:20 GMT -5
Last week I started a batch of quartz that I've found on various beaches along with some partially tumbled Rock Shed quartzes from an old batch. I've read that quartz fractures easily, so I threw in some plastic pellets. When I dumped the barrel out, I found a bunch of unused grit just sitting on the bottom of the barrel. The only other time I've had that happen is on an old batch of quartz that I used plastic with. I don't normally use anything but rock in my 60/90 stage. I know a lot of people hate plastic pellets. Is this one of the reasons? Does it cause the grit to go unused and accumulate on the bottom of the barrel?
Is it necessary to treat quartz differently than other rocks to avoid fractures? I'm doing it in my 3 pound barrels rather than my 6 pounders so it's more gentle. I just removed the plastic and used ceramic instead, but I don't really like using ceramic in 60/90 because it wears it down fairly quickly.
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jamesp
Cave Dweller
Member since October 2012
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Post by jamesp on Sept 4, 2013 21:42:43 GMT -5
I used to use plastic in polish but stopped. I just fill the barrel to about 80 percent. Same thing with quartz. Just fill it a bit more to reduce the avalanche inside the barrel in coarse grind. And the other grits incl. polish. Never used plastic or ceramic after that.
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Post by Jugglerguy on Sept 5, 2013 14:38:07 GMT -5
I'm only concerned with the 60/90 stage, because everything else is done in a vibe. Ceramic works great in my Lot-O and seems to last a long time. I like your idea of over filling though.
Has anyone had my same experience with plastic?
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Deleted
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Post by Deleted on Sept 5, 2013 15:36:59 GMT -5
Rob; I don't think the plastic is making the grit more than gravity is.
Further, I don't think you NEED plastic in rough grind.
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Post by Jugglerguy on Sept 5, 2013 20:55:33 GMT -5
I probably don't need the plastic in rough grind. It's just bugging me trying to figure out why this happens when I use plastic. It's happened several times and I think it has only happened when I use the pellets. I can't be the only one who has had this problem.
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rolanstones
noticing nice landscape pebbles
Member since August 2013
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Post by rolanstones on Sept 5, 2013 22:25:01 GMT -5
Rob, as you know i am no expert here. I have been using plastic pellet in the coarse 60/90 grind for a week and it has been behaving very oddly. I am seeing a metallic sheen on the surface when I have checked the barrels, and it appears the grit is not creating much slurry. For the first 3 days, the stone lifted out of the grit and pellet mixture, was still uncoated and color showed. Today when a I checked, there still appears to be alot of grit and the metallic surface sheen is on the top surface. The stone looks more rounded but there is no slurry like I have seen before on previous tumbles, since I started this.
I only used pellets because this is Spectrolite and rutilated quartz, and I did not want to loose material to chips and fractures. I am tempted to wait until tomorrow and remove the pellets and add more stone but have been hesitating, not sure if this is normal but it seems wrong.
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jamesp
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Member since October 2012
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Post by jamesp on Sept 6, 2013 1:42:59 GMT -5
If you add 25-30 percent small quartz/agate chips and run barrel fuller you will really stop it.
I run sharp hammer broken stuff like that tough coral and Texas agates at 60 to 65% full with no grit and water normal(just below the rocks). To break all the sharp edges off. After 3 days there is a pile of small chips and mud that simply broke off from tumbling. I clean that out and then go to 75% full w/60 grit.
It is very load w/60-65% load. That would frost the heck out of rose quartz, amethyst and all other crystalline quartz's. I can tell by the sound of the hard plastic barrels i use.
I have fine rose quartz local to tumble and it does fine as long as i fill 80-85 %. This overfilling process eliminated a lot of problems.
I know polish is not your issue but this is directly related.
70-75 percent full gives coral decent polish after 1 week 80 -85 gives almost a lotto polish after a week. 60-65 gives terrible polish and usually frosts whatever is in there because the slurry is so thin and watery and the impact is too violent from the avalanche.
iam so glad to get a great polish out of a rotary w/out plastic or ceramic.
25% small pieces crushed of similar material being tumbled will solve a lot of problems. Like pea gravel sized stuff.
I feel like there is a racket selling plastic. I quit and do just fine by overfilling
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Sept 6, 2013 9:07:26 GMT -5
I have used plastic pellets in 60/90 before. Maybe three or four times. It never does well. You don't get a good slurry and there is always a lot of unused grit. I think is because they are doing what they are supposed to do, cushioning the rocks, and therefore slowing down the action. I do have good luck with them in the 220 & 600 courses which I run for 10 days rather than the 7 days suggested by most. They also work good for me in polish which I run for 14 days. That's all in rotary. The longer run times are mostly because I'm expecting slower action. So yeah .... I've experienced the same thing. Don't even try using plastic in 60/90 anymore.
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bwinslow
starting to shine!
Member since August 2013
Posts: 36
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Post by bwinslow on Sept 6, 2013 13:16:04 GMT -5
I used to use plastic in polish but stopped. I just fill the barrel to about 80 percent. Same thing with quartz. Just fill it a bit more to reduce the avalanche inside the barrel in coarse grind. And the other grits incl. polish. Never used plastic or ceramic after that. Ever have issues with the extra weight bogging down the machine? I think I may have over filled my barrels, even tho I don't think they were fuller than 75%, and thought I was getting some belt noise that I didn't notice the first barrel I ran the first week. Played around with tightening the belt, but noise seems to not go away now.
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bwinslow
starting to shine!
Member since August 2013
Posts: 36
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Post by bwinslow on Sept 6, 2013 13:21:30 GMT -5
Last week I started a batch of quartz that I've found on various beaches along with some partially tumbled Rock Shed quartzes from an old batch. I've read that quartz fractures easily, so I threw in some plastic pellets. When I dumped the barrel out, I found a bunch of unused grit just sitting on the bottom of the barrel. The only other time I've had that happen is on an old batch of quartz that I used plastic with. I don't normally use anything but rock in my 60/90 stage. I know a lot of people hate plastic pellets. Is this one of the reasons? Does it cause the grit to go unused and accumulate on the bottom of the barrel? Is it necessary to treat quartz differently than other rocks to avoid fractures? I'm doing it in my 3 pound barrels rather than my 6 pounders so it's more gentle. I just removed the plastic and used ceramic instead, but I don't really like using ceramic in 60/90 because it wears it down fairly quickly. Glad this thread has been made, I will be giving my first attempt at quartz soon.
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jamesp
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Member since October 2012
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Post by jamesp on Sept 6, 2013 14:46:11 GMT -5
bwinslow-I got powerful machine that will not bog. Like a homemade with automotive v-belts. it's a beast.
I will say that if you put 1.5 inch quartz pebbles and no smalls w/it you should get glazing and moons.
No substitute like running quartz with a lot of crushed quartz with it. If you have high dollar amethyst or what ever go get some ugly quartz and beat it to small pieces for padding I personally like small pea sized tumbles out high grade rock.
Same thing for most any tumbles. That's why the tumbling book says a broad range of sizes.
And the bigger the pieces the harder they hit. So smalls are the way to pad. Smalls never frost. Too small to hit hard enough to frost......
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Post by pghram on Sept 6, 2013 15:37:31 GMT -5
I've used plastic but not in course. I have used ceramic from 120/220 and finer all the way through polish with really good results. I have also used pea gravel to good advantage. It's the cheapest & a few turn out to be keepers. The nice thing about ceramic & pea gravel is that it can go through all the stages with the stones.
Rich
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Post by Jugglerguy on Sept 6, 2013 15:41:28 GMT -5
Thanks tkvancil, I'm glad to hear I'm not the only one. I suppose it could be just that simple. It's grinding so slowly that the grit doesn't get used.
James, I like your advice. I'm only running my rock in 3 lb. barrels, so it's probably pretty gentle anyway, but overfilling and using lots of smalls sounds like it couldn't hurt. I was running a couple batches with too much big stuff recently so I picked up a small bucket of pea gravel sized beach stones when I was up at Lake Superior this summer. I'll just throw some of those in.
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jamesp
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Post by jamesp on Sept 6, 2013 16:22:39 GMT -5
I put a few rose quartz about 1-1.5 inches in every load of agate/coral from my local Hogg Mine. It loves to frost.
I put it in there to see the general health of the coarse grind. With coral i remove coral to 60-70 percent full to make the rose quartz frost. That way it is grinding the coral hard. I can now listen and hear if they are running on the hard side w/out the rose quartz testers. But the coral will rarely frost.
I learned how to set up the fullness of the barrel by watching the rose quartz. I ruined several full tumble loads. i love my super fast tumblers. They were born from the hard coral. That is 80% of what i tumble. I can do 1/2 moss agate and 1/2 coral and the moss is round in half the time of the coral.
I will tell you that i run very fast at 60 rotations per minute in 7 inch barrels. And can do rose quartz with zero frost. The trick is to keep the barrel full to 80-85%. The biggest problem is in the beginning. I have to add rose quartz about every day till they stop getting small so fast. If you leave it for 3 days and the rock volume reduces from 85% to 70 percent the rose quartz is toast. Frost city.
I am working on a larger diameter 13 inch barrel. Yes, fill it to 80%. What is the difference? The shear weight of the grinding action. Let's be the devil's advocate.If the barrel was 6 feet in diameter say running slowly and gently and was 85% full think about how much (slow) grinding force would be bearing down on the rocks. The shear grinding force due to weight with low impact. Like a glacier-ha. That kind of slow grinding action will never frost. Frost is from speed impact. Tire tumblers the are 1/3 full are rock destroyers. Ok for granites maybe. But the avalanche within frost most quartz products.
I went thru sinking plastic pellets,floating ones,tile spacers,ceramics,granite pea gravel. The best protection for your valuable stones is by filling the barrel more. But not so much that they do not tumble.
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1nickthegreek
spending too much on rocks
Member since February 2014
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Post by 1nickthegreek on Mar 12, 2014 14:21:17 GMT -5
I am not so new to tumbling, and I DO run floating plastic from coarse to final polish, changing pellets between major grits. However I mainly tumble labradorite and mahogany obsidian, not together of course but they seem to do better this way. But I have had excellent success using plastics in addition to ceramic to add volume to my barrels because we all know that a shortfill is harder on the stones than a 85%+ fill :-)
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jjdub
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Post by jjdub on Mar 12, 2014 14:29:39 GMT -5
I have used plastic pellets in 60/90 before. Maybe three or four times. It never does well. You don't get a good slurry and there is always a lot of unused grit. I think is because they are doing what they are supposed to do, cushioning the rocks, and therefore slowing down the action. I do have good luck with them in the 220 & 600 courses which I run for 10 days rather than the 7 days suggested by most. They also work good for me in polish which I run for 14 days. That's all in rotary. The longer run times are mostly because I'm expecting slower action. So yeah .... I've experienced the same thing. Don't even try using plastic in 60/90 anymore. My experience with plastic on 60/90 has bee the same. Everything tumbles fine, however the grinding action is significantly slowed.
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