How'd They Do That?

How'd They Do That?

Bill Skinner
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Bill Skinner
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Joined: May 1st, 2011, 3:00 am

July 4th, 2018, 4:31 pm #1

This is inspired by the thread about making copper.

In the southeastern US, during the late Woodland Period to the end of the Mississippian Era, the Native Americans practiced working copper down to thin sheets and then making ornaments and jewelry from them.  They did chasing and reppose with non ferrous tools.  And probably not by setting the metal in a bowl of pitch mixed with tallow and plaster while they did it.

I am working or more properly, fiddling, with copper, trying to make something that looks sort of similar.

Anyone got any ideas?

PS:  Putting the copper nugget on a rock and beating on it with another rock will only work so so.  It doesn't get the copper down to 1/2 mm (.02 inch)  or less like the NA's did.  Right now, I am having some success with a smooth rock and an ash stump as an anvil. I believe that sanding may have been involved.   And work hardened copper can be used to cut and punch holes in heat softened copper.  And I do know what "air reposse" is and I think that may have been used. 

 
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Hummingbird Point
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Hummingbird Point
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July 4th, 2018, 5:18 pm #2

I know about nothing on the subject, but would offer the possibility that the copper used was especially soft .   Gabriel Archer, one of the Jamestown settlers, in being given a piece of native copper by a local chief noted:  "The copper he had, as also many of his people, was very flexible.  I bowed a piece of the thickness of a shilling round my finger as if it had been lead."
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Robson Valley
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Robson Valley
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July 5th, 2018, 2:28 am #3

Copper work hardens when you beat on it or bend it.  
Some expected shift in the molecular structure.
You can mess that up with heat and slow cool.
Maybe some unexpected alloy could stay flexible but not any of the copper that I have.

I used 1/4" copper rod to forge a crude crooked knife.  
I got 2 swings of the 32 oz hammer then had to re-heat.

Learning that my striking accuracy was poor and my torch wasn't hot, I had a blacksmith
forge an adze blade from 1.5" x 6" x 1/4" copper plate.

I can't imagine a paleo process to forge a sheet from native copper nodule.
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Bill Skinner
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Bill Skinner
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July 6th, 2018, 10:05 pm #4

Well, they did it.  So it can be done.  I just like trying to figure out how.

EDIT:  This is a guess, so I may be wrong.   The copper in the sites that I know here in N America is mostly something like 99.9% pure copper.  A lot of the European stuff was actually an alloy, especially the metals used in coinage.  Tin was added to make the metal tougher and more wear resistant.
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Forager
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Forager
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Joined: October 22nd, 2010, 11:42 pm

July 7th, 2018, 3:49 am #5

Bill, a Lenape friend whom I see annually (or less) at primitive skills/experimental archaeology events once set out to attempt to replicate thinned and rolled cylindrical copper beads made by his ancestors.  He got some copper from the Great Lakes and hammered it thin with a stone, burnished it and succeeded in rolling it into beads which very closely approximated those he'd referenced from the archaeological finds.  I considered his patient and persistent efforts successful.  

He encountered difficulties in his trials, as I recall there was a tendency toward cracking (which he resolved) and he was unable to achieve exceptional thinness (although he matched the ancient models which weren't remarkably thin).  My sense from his reflections was that the challenges pertained more to the purity of the specific (geologic) grade than the methods he employed.  I do not recall him using heat - just percussion and pressure, if my memory is accurate.

Good luck on your experiments, I'll be among those cheering you on from the sidelines.
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Bill Skinner
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Bill Skinner
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July 7th, 2018, 5:03 pm #6

I can already do the Mississippian style rolled beads, working the smaller pieces down is time consuming but not difficult.  If it's cracking, just heat it up.  Those pieces are about the size of a stick of gum though.  I want to be able to make the larger pieces, about the size of your hand and larger, up to about plate sized.  I have hammered a chunk that started out about the size of the smallest joint of your little finger into a piece about a little larger than a 3 X 5 card.  It has lots of little tiny flats from the points and rough spots that are basically flattened mushrooms.  The top hammered out flat but the they  are still attached in the middle.  When I put a nugget on the ash stump, those small rough spots stuck int the wood and some of them came off.  I'm using a smooth quartzite hammer stone, BTW.  Other problem is the middle is still too thick, around .04 or a little less.  That's a little thinner than a penny.  This is thick enough to destroy the bone and antler tools I an using to make lines and impressions, though.  
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