Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 13, 2017 16:20:18 GMT -5
So I have been tumbling with 3 rotary barrels since January and have seen gas buildup before and managed to burp the air out before anything bad happened. I usually try and check the barrels often but just never seemed to have a problem so I got where I didn't check on them for days. I was out in the garage to get some tools and noticed one of my 6 pound barrels being extra noisy, having my attention I looked in terror as I noticed the slurry all over the area. This was some new kind of rock for me that looks very much like Flint that I acquired while canoeing 3 weeks ago so I didn't know to keep a close eye on the operation. Now where is a roll of paper towels . . .
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 13, 2017 18:10:19 GMT -5
OK not so bad, the slurry had become very thick and remained under the tumbler in a pile. Must have happened a short time ago as nothing was starting to dry. Cleaned off the Loretone QT66 frame and happy to see that no slurry had gotten into the bearings. Everything will dry out for a day and I'll get 2 more barrels rolling on it after it gets lubed up.
I decided to make my Rock Day sooner and did all three barrel cleanouts. It was interesting that I had some rocks in polish where the barrel was leaking considerably before I opened the lid, but no mess there thankfully.
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Post by manofglass on Sept 13, 2017 23:02:23 GMT -5
Tumble it in a PVC can with a test plug The plugs don't blow out on them
Walt
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Luminin
spending too much on rocks
Member since August 2017
Posts: 400
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Post by Luminin on Sept 14, 2017 17:00:43 GMT -5
Good to know that (maybe?) flint is a risk for gas buildup! I plan on making a trip soon to collect some!
Glad all turned out for the best!
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Post by Garage Rocker on Sept 14, 2017 17:22:37 GMT -5
Good to know that (maybe?) flint is a risk for gas buildup! I plan on making a trip soon to collect some! Glad all turned out for the best! Your Flint Ridge material will have no noticeable gas build up. We will expect photos of your trip!
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Luminin
spending too much on rocks
Member since August 2017
Posts: 400
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Post by Luminin on Sept 15, 2017 3:13:01 GMT -5
I'll do my best to take plenty! Might be tricky as it'll probably be just me. Thanks Garage Rocker!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Sept 15, 2017 6:37:02 GMT -5
Water has a lot of variation in ph. Ever seen the reaction of baking soda and vinegar ? Gas galore. Just curious what types of ph cocktails are being generated in the tumbler. ph reactions are most common. Dasani is acid 3.04 , Essentia is alkaline 9.26. Wide range, about as wide a range as baking soda and vinegar. Am I missing something ? Guaranteed, tumbling alkaline lime bearing type agates with Dasani ph 3.04 acid water is going to generate gas. Got to. Does not make sense Dasani is ph 3. But water does vary greatly. Acid water with acid rocks or alkaline water with alkaline rocks makes sense. Not sure how you would measure the ph of rocks. Unless you measure their slurry, and then you need to know the ph of the water you mixed with the rocks.
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Post by TheRock on Sept 15, 2017 22:11:52 GMT -5
Interesting. I have a reverse osmosis system and through a carbon filter I run 7.8 ph If I run into flint I will keep that in mind.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Sept 16, 2017 5:23:28 GMT -5
Gas is usually created in coarse grind. I ran rotaries for a long time and never had gas buildup in 220-500-1000-14,000 steps. Always during coarse grind when rocks are being shaved off. No doubt the chemistry is most active during coarse.
Even more obvious when running glass or obsidian during coarse grind. Glass and obsidian is about as chemically inactive as it gets. But it is full of small bubbles holding highly pressurized gas that are released during rapid shaping.(likely that rocks have the same pressurized bubbles) Not a chemical reaction, but a release of compressed gas.
PV1 X PV2 is calculation for volume of compressed gas. Ideal Gas Law ?? Should work for a tumbler barrel at room temp. For example a 3 cu.ft. oxygen tank at 3000 psi would hold 600 cu. ft. of oxygen at normal room pressure of 15 psi. I doubt glass or rocks have 3000 psi gas pockets but it does not take many pressurized pockets to increase volume/pressure rapidly in a sealed tumbler barrel.
Try a 1/8" say square gas pocket at 500 psi in a rock:
1/8 X 1/8 X 1/8 = 1/512 cu in.. 500/15 = 33. Then 33 times 1/512 = 33/512. Just saying, a 500 psi gas pocket would hold 33 times more gas at room pressure. A 1000 psi pocket would hold 66 times more volume at room pressure. A 2000 psi pocket would hold 132 times more volume at room pressure.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Sept 16, 2017 6:18:49 GMT -5
Lol, title to article - "What makes volcanoes explode? It's the bubbles" Interesting, over my head but discusses explosive power of bubbles in obsidian and other volcanic rocks: www.berkeley.edu/news/media/releases/2003/11/26_bubbles.shtml"Most obsidian has gray and black bands, but there is no good explanation why," Manga said. The gray bands are often the same composition as the black bands, they just contain more microscopic crystals or bubbles." "A 2-cm wide slice through a piece of banded obsidian from Big Glass Mountain in northern California. The bands, which contain different concentrations of microcrystals of the mineral pyroxene, are created by shear forces as the magma rises under the volcano and as it flows on the surface. According to a new theory of volcanic eruptions, this shear breaks the magma and the bubble walls, allowing gas to escape and leaving little for an explosive eruption. The debris from such broken and sheared bubbles then collapses, reanneals and becomes stretched into thin bands. Breaking, reannealing and stretching may occur continuously as the magma rises hundreds or thousands of meters to the surface. (Helge Gonnermann/UC Berkeley)" Conclusion- Don't be surprised if some rocks have extreme pressurized bubbles. Mt St Helen Tumblers Inc. Champagne: "The conventional explanation holds that in explosive eruptions only, rising magma breaks or fragments as it approaches the surface, releasing bubbles that blow the magma out like champagne from an uncorked bottle."
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zekester55
starting to spend too much on rocks
Member since March 2017
Posts: 111
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Post by zekester55 on Sept 17, 2017 6:39:46 GMT -5
Interesting that this happened with QT-66 barrels, as they have a pretty solid seal. I've done most of my stage one tumbling in my Covington, which has a vented cover. You got me thinking! I imagine my little 3 lb. Thumler barrels would have blown right out.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 17, 2017 14:12:33 GMT -5
Yes the QT66 barrels have a very aggressive seal but the pressure was just too much for it. I finally got it all put together and have the two QT66 barrels rolling in course grind starting a couple of hours ago. The material I'm tumbling come from a large local stream called the Flint River and looks like a cross between Chert and Flint with some sandstome mixed in a little. Here is a picture of the stone that was in the tumbler when it blew up, It has been restarted today . . . And here is the stone freshly broken up after coming from the river . . . These barrels will be closely watched.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 18, 2017 19:37:51 GMT -5
After 30 hours those same rocks had the barrel bulging with gas again. Burped it out and tried to seal it back up with Negative Pressure to try and get it to last a little longer. The second barrel on the QT66 is just fine but it has mostly quartz type landscaping stone in it.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,422
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Post by Wooferhound on Sept 20, 2017 17:55:47 GMT -5
Wow that rock is active ... Burped the barrel again this morning, then went to setup Dwight Yoakam at the concert hall.
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Post by Garage Rocker on Sept 21, 2017 6:05:07 GMT -5
Guitars and Cadillacs...
The music is ok, but that performance in Sling Blade was Oscar worthy.
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