jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 27, 2014 13:02:19 GMT -5
Made a large sound. This coral was too porous and full of water. A few dents and separated weld in corner.
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Post by rockjunquie on Jul 27, 2014 16:13:37 GMT -5
WOW! That as a lot of force! Goodness. Glad you weren't around when that happened.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 27, 2014 16:21:54 GMT -5
WOW! That as a lot of force! Goodness. Glad you weren't around when that happened. It was very loud and i could feel it thru the ground Tela. Never had one burst like that. The door on the oven is hard to close. Glad too !! Have seen rocks bust at a campfire, this one would have hurt someone.
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Fossilman
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Member since January 2009
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Post by Fossilman on Jul 27, 2014 17:56:28 GMT -5
"BOOM"
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stephent
starting to spend too much on rocks
Member since March 2014
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Post by stephent on Jul 27, 2014 21:51:08 GMT -5
Had a few campfire rocks explode before.. makes a mess and there's usually scrambling around trying to figure out what happened.. lol I used an old covered roasting pan in the oven when I "cooked" a batch of Chert a few months ago. I brought the oven up to 215-220 for 2+ hours before cranking the heat up another 25 degs er so. It took over 5+ hours for me to finally set the heat up to 525 for a couple of hours. Your rock probably had less then a pinky fingertip sized pocket of water in it....and sealed tight!
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junglejim
spending too much on rocks
Member since January 2014
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Post by junglejim on Jul 27, 2014 22:30:40 GMT -5
Wow, that is scary. Definitely lucky nobody was injured. Reminds me of an incident I had while pouring some jigs. I had some large lead bell sinkers that had been sitting in my basement for years and were "dry". Apparently water had gotten inside a hollow pocket and rusted the sinker sealing water inside. When I dipped it into my melting pot it exploded sending molten lead everywhere. Ceiling, table and my shirt had it sprayed on it. I was sitting down so had no idea how I got away with only a few small burns on my hand and a piece of lead hanging from my eyelash. I was that close to losing an eye. actually took pictures of the lead hanging from my eyelash. I always wear eye protection now.
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quartz
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breakin' rocks in the hot sun
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Post by quartz on Jul 28, 2014 0:45:54 GMT -5
Fortunate the oven is sturdy.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 28, 2014 4:41:39 GMT -5
Had a few campfire rocks explode before.. makes a mess and there's usually scrambling around trying to figure out what happened.. lol I used an old covered roasting pan in the oven when I "cooked" a batch of Chert a few months ago. I brought the oven up to 215-220 for 2+ hours before cranking the heat up another 25 degs er so. It took over 5+ hours for me to finally set the heat up to 525 for a couple of hours. Your rock probably had less then a pinky fingertip sized pocket of water in it....and sealed tight! It was water logged, pulled out of the river stephant. Heated it at 200F for 30 hours and let it cool/dry for a day and then ramped it to 600F over a 20 hour period. It popped at about 550F Old material that has been sitting out in the sun for a couple of years never causes trouble. It was ill formed and porous and like you said, sealed with water pockets.
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stephent
starting to spend too much on rocks
Member since March 2014
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Post by stephent on Jul 28, 2014 9:45:06 GMT -5
wow... 600+ psi pressure at 480+F ..I was curious and looked it up in a steam table--- temp vs pressure. That rock was a small bomb.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 28, 2014 11:03:57 GMT -5
wow... 600+ psi pressure at 480+F ..I was curious and looked it up in a steam table--- temp vs pressure. That rock was a small bomb. What did the tables say stephant ? Oh, i see, 600 psi. what about 600F ?
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Post by rockpickerforever on Jul 28, 2014 20:03:04 GMT -5
James, maybe you need to build a safety cage around your oven? Water+ heat = steam + pressure = bomb. Ouch! Glad there were no casualties.
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stephent
starting to spend too much on rocks
Member since March 2014
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Post by stephent on Jul 28, 2014 20:40:19 GMT -5
600F is just a tad over 1500 psi o.O .. plenty enuff to make a solid rock go BANG with a 10th teaspoon of water tightly contained...at least until the stress goes higher then rock is capable of keeping inside.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 28, 2014 20:57:40 GMT -5
James, maybe you need to build a safety cage around your oven? Water+ heat = steam + pressure = bomb. Ouch! Glad there were no casualties. At about 500F i dial it to 600F and leave it for 4-5 hours. I may just stay away from it and let it do it's thang. That piece was very porous and junky. Normally i don't put porous stuff it there. The coral w/polyps does not break well so i saw it. It obviously makes a good boom. The glassy stuff may fall off in layers after you take it out of the oven.
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jamesp
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Post by jamesp on Jul 28, 2014 20:59:35 GMT -5
600F is just a tad over 1500 psi o.O .. plenty enuff to make a solid rock go BANG with a 10th teaspoon of water tightly contained...at least until the stress goes higher then rock is capable of keeping inside. Big pressure increase for 120F rise. Thanks for the reference stephant. Not a linear increase.
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transcendental
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Post by transcendental on Jul 28, 2014 21:15:32 GMT -5
Ok noob question....why were you cooking it? Glad your ok
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stephent
starting to spend too much on rocks
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Post by stephent on Jul 28, 2014 21:24:40 GMT -5
Nope not exactly linear all the way from froze to 1000C. Max volume for pure liquid water occurs at 39 degs, too. Obviously ice expands more in volume.. But it really gets excited at boiling temp at 730x (+/-) expansion.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Jul 28, 2014 21:48:03 GMT -5
Ok noob question....why were you cooking it? Glad your ok Hi transcen. I heat the rocks to alter the color. This is petrified coral from Zephyr Hills Fl. Before After corals from many locations after heated
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jamesp
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Post by jamesp on Jul 28, 2014 21:51:13 GMT -5
Nope not exactly linear all the way from froze to 1000C. Max volume for pure liquid water occurs at 39 degs, too. Obviously ice expands more in volume.. But it really gets excited at boiling temp at 730x (+/-) expansion. Super heated steam ain't nothing to play with. It's just water....
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quartz
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breakin' rocks in the hot sun
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Post by quartz on Jul 28, 2014 23:47:51 GMT -5
Yup, just water that has/had enough power to power the world for many years. I've seen pics. of steam logging donkey boilers that blew up, nothing to fool with.
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plumberinaz
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Post by plumberinaz on Jul 29, 2014 1:23:16 GMT -5
Crazy man... Glad your ok!
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