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Post by Toad on Jun 6, 2020 7:54:52 GMT -5
I bought a large piece of mookaite years ago and never did anything with it - mainly because it wasn't much to look at. So into the fire pit it goes. Weighs exactly 12 pounds and is about 11 inches across. Dug a nice hole in the fire pit. Full bag of sand at the bottom. Top of the rock about 4 inches below ground level. Another bag of sand over the rock and then dirt to bring it to about 2 inches below ground level. That way the coals are keeping their heat rather than the wind whisking it all away. Fire started at 6:30am and will go at least 12 hours. Will get another pic after I have a nice bed of coals going.
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Post by rockjunquie on Jun 6, 2020 8:30:21 GMT -5
Oh cool! Anxious to see the results.
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whyofquartz
spending too much on rocks
So, Africa is smaller than I expected...
Member since December 2019
Posts: 316
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Post by whyofquartz on Jun 6, 2020 8:52:19 GMT -5
FIRE! Rock with me
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Post by hummingbirdstones on Jun 6, 2020 8:53:23 GMT -5
Looking forward to seeing what happens with the Mook. I don't think I've ever seen someone try to heat treat that before.
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Post by orrum on Jun 6, 2020 9:48:28 GMT -5
Dont dig it out to soon. Leave it for days to cool gradually. If too early you risk cracking. Good luck and great thread!!!
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Post by Toad on Jun 6, 2020 10:00:39 GMT -5
I'll leave it in the ground for at least two days after I'm done with the fire tonight. Not too worried about it cracking as it will be going in the tumbler anyway.
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Post by Toad on Jun 6, 2020 21:51:06 GMT -5
After 16 hours. Haven't put new wood on the fire for a couple hours now. Healthy bed of coals should keep the rock warm overnight... Will probably try to dig it up after work Monday or Tuesday at the latest.
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Post by Toad on Jun 7, 2020 6:31:59 GMT -5
So not long after the previous picture was taken, I was dozing by what was left of the fire, watching the remaining wood turn to glowing embers when my dog decided to dance with a skunk. So a busy, beautiful day ended up on a bit of a sour note. I took one more picture this morning. About 25 hours after the fire was started, here is all that is left: Now I wait for everything to cool down nice and slow...
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Post by orrum on Jun 7, 2020 8:50:19 GMT -5
Good waiting the earth insulates and holds heat very long. Wowser this is such a great thread!!! Thanks.
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mjflinty
spending too much on rocks
Member since September 2011
Posts: 356
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Post by mjflinty on Jun 7, 2020 12:43:24 GMT -5
Neat experiment. When I tried this, I planned on using the stone for flintknapping (making stone tools) so I broke it down into rough preforms. I found the heat penetrated the outer portion of the stone and several thicker pieces (2+ inches) did not get heat treated in the middle and needed to be worked down and heated again. You will likely see the same thing in the large piece you heated. Looking forward to seeing your results.
Michael
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Post by knave on Jun 7, 2020 12:52:38 GMT -5
How hot is typicality required? Could a person use a charcoal grill?
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Post by Toad on Jun 7, 2020 14:01:25 GMT -5
Don't really know hot it is supposed to get, and no way to regulate a bonfire. We'll see what happens...
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Post by RickB on Jun 7, 2020 15:12:57 GMT -5
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Post by rockjunquie on Jun 7, 2020 16:29:42 GMT -5
I just glanced over that page that RickB posted looking for an answer to my question: Why do you heat treat for knapping? I found it, but I also found this: "...this book addresses only heat treatment for making rock more "chippy."" OK, so now I'm thinking I have had a lot of mookaite that was pretty chippy. Does that mean it was likely heated for color and as a result became more chippy? Sorry if that sounds like a dumb question.
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Post by Toad on Jun 8, 2020 6:39:49 GMT -5
I’m not a knapper, but from what I read lower quality material is often heat treated to make it more workable. So your material was either better quality or was heat treated - maybe both.
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Post by drocknut on Jun 8, 2020 9:14:03 GMT -5
Cool pictures, looking forward to seeing the end results. Around here that would not be possible to do right now, we are under a burn ban. It is very dry here and we have already had numerous wildfires.
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Post by Toad on Jun 8, 2020 11:05:52 GMT -5
Can’t remember the last time we had three days without rain. Worked perfect for me - dry and not too hot
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Post by orrum on Jun 8, 2020 12:23:42 GMT -5
Let her soak in that heat.
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Post by Toad on Jun 8, 2020 14:01:34 GMT -5
In about 2 hours I’m about to see how much heat the ground holds. I’m guessing the coals weren’t generating too much as of Sunday morning. So 36 hours later should be pretty safe. I hope...
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Post by Toad on Jun 8, 2020 17:11:31 GMT -5
No luck all. I stuck a trowel into the ashes for less than 10 seconds and it came back very warm. Tomorrow night now. Supposed to rain Wednesday...
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