Primitive Archer
Main Discussion Area => Flintknapping => Topic started by: Prarie Bowyer on November 29, 2012, 02:38:02 am
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Anyone know a video on how to get started in a raw rock? Cortex and everything?
Also. I have these rocks that are like an amber honey in my landscaping. They "should" knapp... they aren't the biggest BUT they are pretty and SUPER hard. Infact the latter makes them just about unknappable it seems. Anyone know what that is and if heating them will soften them?
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from what ive seen and heard, very hard rock becomes more manageable when you heat treat it. It depends on the temp of course, if you think about it logically you will see that when metal is heated really hot and then let cool very slowly it becomes very soft, where as if you dip it in something until it cools in a few seconds then you have just made it harder. so basically if you heat something up and cool it fast you will tighten the density of molecules thus making it harder, and vise versa is true about heating it up and allowing it to cool over about 12 hrs unlike you did previous, you will find that the molecules we not able to compact as fast, that is because when something is cold it has more molecules per inch cubed than that same substance in a hotter form. So if you are rapidly cooling a substance you will make the molecules compact tighter than if you let it cool off slowly, in any case, when you heat treat rock i believe that is what you are doing, you heat it up to about 600-800 degrees for 8-12 hrs and you let it cool off slowly, thus making it much softer. This principal is why glass shatters when you rapidly heat it and then cool it rapidly. the molecules cant handle the compression and it breaks. I hope that made sense? Good luck on whatever you choose to do, and make sure to post pics of the lovely rock!
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That is true for Ferrous metals... non ferous metals like copper and silver are the opposite actualy. It's more about alignment of the microchystaline structure.
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ok, i dont know then ???
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A pic of the rock would help. Really hard grainy rock does well with wooden billets
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Here's one of my vids on spalling raw chert: ;D
https://www.youtube.com/watch?v=cNn8ujT6Fgg&list=PL167E6ACEDB32F0B9&index=5&feature=plcp
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That video of Patricks is very good.
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Thanks, Don!
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Excellent vid brother
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When you heat Burlington....The quartz melts a little and so the wave generated by striking the stone can flow through the material not around the quartz structures.