Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #21   Report Post  
Old June 18th 04, 05:15 PM
Yuri Kuchinsky
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Gary Coffman wrote:

On Wed, 16 Jun 2004 22:22:21 +0100, Doug Weller wrote:
On Tue, 15 Jun 2004 16:53:26 -0400, Yuri Kuchinsky wrote:

Gary Coffman wrote:

[snip]

Casting dumb, smithing smart.

But casting and/or smithing (depending on the materials at
hand) is more smart than just smithing.


Yuri has me killfiled so may not see this, but I am fed up with his going
on about 'smart' and 'dumbing down'. It takes more than intelligence to
develop technologies, and the lack of a technology does not mean that a
group of people are 'dumb'. To say that Native Americans did not develop
electricity, nuclear power, or various types of metalworking does *not*
mean that they are dumb. And it doesn't make the person making the
statement racist.

This is basically just Yuri's need to cast nasturtiums at scholars, this
time archaeologists. He does the same thing with Biblical scholars in other
newsgroups.


I picked up on the fact that he was more interested in axe grinding than
casting.

Gary


Hi, Gary,

My main interest in all this is to investigate Native
American history.

There are apparently hundreds if not thousands of
pre-historic metal furnaces that have been described all
over northern US. So it sure looks like the Native Americans
must have been smelting or melting something. Probably
copper, iron, maybe bronze.

Some non-professional archaeologists have investigated these
things, and published their findings.

I find these things quite fascinating. And yet professional
American archaeologists don't seem to show any interest at
all. They insist on looking the other way. Why do you think
this is so?

Regards,

Yuri.

Yuri Kuchinsky -=O=- http://www.trends.ca/~yuku

Reality is that which, when you stop believing
in it, doesn't go away -=O=- Philip K. Dick

  #22   Report Post  
Old June 18th 04, 05:34 PM
Seppo Renfors
 
Posts: n/a
Default Copper Casting In America (Trevelyan)



Gary Coffman wrote:

On Tue, 15 Jun 2004 05:29:28 GMT, Seppo Renfors wrote:
Gary Coffman wrote:
On Thu, 10 Jun 2004 15:36:41 -0400, Yuri Kuchinsky wrote:
Copper Casting In America (Trevelyan)

[..]
So here we see the sort of an anti-Native bigotry that is
still all too common within our professional archaeological
establishment. These folks really still live in the middle
ages!

What a dark snake-pit of racism and bigotry our academic
establishment is... This never ceases to amaze me, I must
say.

This is the Dumbing-Down Crew that is hard at work to deny
the cultural achievements of Native Americans.

Realize that casting is primarily a technique used for cheap mass
produced items. It allows relatively low skilled workers to produce
large numbers of relatively complex identical items. Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.

Given that, it seems to me that your claims of bigotry by a art
historian are unfounded. If anything, the idea that the art objects
were produced by cold work makes them even more impressive
examples of the skill of the worker than if they were mere castings.


Whilst there is little argument with that, it is still illogical to
believe that casting wasn't done. Each maker of jewellery, ceremonial
items would have ended up with "scraps" of copper. It is unlikely they
would have simply been thrown away. The annealing of copper would
bring it to melting temperature often enough for smaller thinner bits.
It suggests a very likely occurrence that they did melt copper, if for
no other reason than to make bigger pieces out of the small scraps and
off-cuts. This they would again cold work another time.


If they did open atmospheric casting (and I'd strongly contend they
didn't have the technology to do any other kind, nobody did until the
latter half of the 19th century, and then only as a laboratory curiosity),
the resulting copper wouldn't be suitable for cold work, too much
porosity.


I agree that is most likely to have been the procedure. On the other
hand what we don't really know is if the porosity was a problem for
them.

Note too that the annealing temperature of copper is *way* below
the melting point. If they did melt parts of an object they were
annealing, they were using grossly too much heat. In other words,
it would be a mark of incompetence on their part if evidence of
such melting were found.


I suspect you are using modern ideas as a guide, knowing of other
techniques etc. Back then in learning about melting copper, they must
observe it melt. Learning annealing they again need to observe the
effects, thereby also learning to heat to just below melting point and
lend itself to the "hammer welding" you refer to below.

If they did attempt to salvage copper scraps, they likely *hammer
welded* them. That's done at temperatures below the melting point
of copper, so porosity doesn't become as serious a problem.


.....and it would also eliminate porosity, would it not? So the small
bit could well be melted and cast into a small ingot - to later
"hammer weld" the porosity out of it.

You need to understand that copper behaves *differently* from silver,
gold, or even iron. Those metals respond well to casting techniques.
Nearly pure copper does not.


I'm aware of the difficulty - as well as the evidence it provides of
casting. As such evidence does exist, even if not widely, it indicates
the ability to melt copper.

(Bronze is a different matter, of course, but there still has been
no evidence presented of bronze artifacts from the locale and
period under discussion in this thread.)

But that said, casting pure copper is a bitch. Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.


IIRC silver is found in with copper deposits in the Great Lakes area
and it has a melting point a bit lower lower than copper. It is likely
they could have used a silver/copper alloy or "bronze". If the
minerals co-exist then there is no need for "mixing", it is automatic
as with arsenic/copper deposits.


A quick search of the UNS database doesn't show any silver-copper
binary alloy listed as suitable for casting.


Try the old 3 cent piece - it was silver + copper alloy. Nor does it
need to be "fit for casting" in the modern sense, as all I see it used
for is to generate a larger lump of material to work with as a smith
would.

Nor is such a binary mixture called bronze.


A copper alloy is in general called "bronze" irrespective of the mix
(eg arsenic + copper) except when it is called "brass" (nickle +
copper?).

The search did turn up "nickel silver" copper alloys suitable for casting,
but the composition of those alloys *contains no silver*. They do contain
large amounts of tin, nickel, and a bit of lead. All of the binary alloys of
silver and copper listed are labeled as "wrought", meaning that they
are suitable only for cold work.

The associated native copper and silver found in the Keweenaw
Peninsula is known as "Halfbreed". It isn't even an alloy (solid
solution). It consists of intertwined gross crystals of the two
separate metals. It is difficult to produce an alloy of silver and
copper in the absence of tin.


No, it has been done a lot of the time. In Sweden (damn I lost the
info tag..) they have something they call "malm" (ore) that is a
bronze, but a far redder colour than normal bronze. I can't tell you
the mix of it as I lost the info. However there is a lot of arsenic +
copper bronze around in Asia Minor. It was mined in the Ural mountains
as a ready mixed ore.

If you heat a sample of Halfbreed, the silver melts out before
the copper reaches melting temperature, leaving a mass of
copper with voids where the silver was. It does not produce
bronze.


It does if you heat it to the melting point of copper.

http://ia.essortment.com/threecentcoin_rlzk.htm


The presence of tin is usually, though not always (aluminum
bronze being the primary exception), a prerequisite for a
copper alloy to be called bronze. I'm unaware of any tin
deposits in the UP of Michigan.


Tin is indeed the most common, but not the sole mix.

Note, an alloy of arsenic and copper was once called bronze
too, but it is dangerous to produce, and exceedingly brittle in
use. Old World artisans very quickly abandoned it. Again, no
evidence of artifacts from the UP of Michigan composed of
that alloy has been presented.


It is still called "bronze" as the "bronze age" term itself says.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.


You see, the thing is that cold working something doesn't require
"technology", where melting/smelting does. It is the implied lack of
technology where the suggested prejudices arise from.


Hmph! You might remember that one of the newsgroups where this
thread is appearing is the *metalworking* group. Most of the members
are machinists, either by vocation or avocation. In other words, their
primary occupation is working of metals at temperatures below the
melting point. They would *strongly* object to the notion that casting
should be the signature mark of metalworking technology.


Ahhh.... but irrespective of the fact that artisans may get their nose
out of joint, melting/smelting metals IS called a "technology". So
having that technology under ones belt in addition to the smithing, is
indeed one up on the smithing alone :-)

Most of the more advanced technological working of metal is done
cold, or at least at temperatures below the melting point of the metal.
That's *particularly* true for pure copper. Most of the more astute
members would never even consider casting as a viable method for
producing pure copper objects.


Not suggesting modern people do cast copper - I am saying ancient
people did.

Note that I am not insisting that no copper casting industry existed
in the UP of Michigan in pre-Columbian times. At least one radiograph
I've seen seems to indicate copper which had been melted in atmosphere
at some point. But what I am saying here is that atmospheric copper
casting is a particularly unintelligent way of utilizing the pure metal
when the alternative of lower temperature smithing is available.


While there is/was almost pure copper available at the time, much of
it had impurities embedded within it. Large hunks of pure copper were
relatively rare. The vast amounts that are indicated to have been
mined must include copper with much impurities or copper embedded in
other material. This had to be refined somehow, melting is the
simplest way of refining it - unless you know of another technique
available to the ancients.

So the apparent fact that most of the artifacts found show evidence
that they were smithed rather than cast clearly indicates that the
Native Americans were sophisticated in the working of the copper
available to them. Insisting that they cast the objects instead would
be an attempt to show that the workers were *not* sophisticated.


Nobody is suggesting that smithing isn't an extremely skilled
occupation..... but then so is flint knapping in my view. The casting
was not used to manufacture anything much apparently. I see it as a
refining process to later be hammered at near melting temperatures,
thereby producing fine artefacts.

A very important indicator of technological sophistication is knowing
how to choose the appropriate method to work with a particular
material. In this case, the technologically appropriate method is
*not* casting. So if your objective is to minimize the technical
prowess of the Native Americans, you'd be in the camp pushing
for copper casting. Casting dumb, smithing smart.


As I said mastering one technology, is less than mastering TWO
technologies.... if you want to call smithing a "technology" in favour
of Art :-)

(Again I must point out that bronze is a different matter, but no
evidence has been presented to support the production of bronze
in the locale and time under discussion.)


I don't know what if any testing of composition of artefacts has been
done. Some bronzes only contain 3 - 5% tin elsewhere. If none are
done then a claim that bronze doesn't exist can't be made. Testing the
metals would also finger print them for origin, which hasn't been done
either to my knowledge.

--
SIR - Philosopher unauthorised
-----------------------------------------------------------------
The one who is educated from the wrong books is not educated, he is
misled.
-----------------------------------------------------------------
  #23   Report Post  
Old June 18th 04, 06:05 PM
Inger E Johansson
 
Posts: n/a
Default Copper Casting In America (Trevelyan)


"Yuri Kuchinsky" skrev i meddelandet
...
Gary Coffman wrote:

On Wed, 16 Jun 2004 22:22:21 +0100, Doug Weller

wrote:
On Tue, 15 Jun 2004 16:53:26 -0400, Yuri Kuchinsky wrote:

Gary Coffman wrote:

[snip]

Casting dumb, smithing smart.

But casting and/or smithing (depending on the materials at
hand) is more smart than just smithing.

Yuri has me killfiled so may not see this, but I am fed up with his

going
on about 'smart' and 'dumbing down'. It takes more than intelligence

to
develop technologies, and the lack of a technology does not mean that a
group of people are 'dumb'. To say that Native Americans did not

develop
electricity, nuclear power, or various types of metalworking does *not*
mean that they are dumb. And it doesn't make the person making the
statement racist.

This is basically just Yuri's need to cast nasturtiums at scholars,

this
time archaeologists. He does the same thing with Biblical scholars in

other
newsgroups.


I picked up on the fact that he was more interested in axe grinding than
casting.

Gary


Hi, Gary,

My main interest in all this is to investigate Native
American history.

There are apparently hundreds if not thousands of
pre-historic metal furnaces that have been described all
over northern US. So it sure looks like the Native Americans
must have been smelting or melting something. Probably
copper, iron, maybe bronze.


copper yes, bronze yes, silver yes(to pour in forms) but not iron. That they
didn't do until they began trading silver, furs and eagles with the Norse
according to the oral tradition I have had from respected Indians I spoken
to.

Inger E



  #24   Report Post  
Old June 19th 04, 05:16 AM
Martin H. Eastburn
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Seppo Renfors wrote:

Gary Coffman wrote:

On Tue, 15 Jun 2004 05:29:28 GMT, Seppo Renfors wrote:

Gary Coffman wrote:

On Thu, 10 Jun 2004 15:36:41 -0400, Yuri Kuchinsky wrote:

Copper Casting In America (Trevelyan)

monster snip

Considering copper :

1. find some rich ore or native or near native.
2. build one hot fire - continue burning and increase coal / charcoal contents.
3. add copper or ore - perhaps using glass technology of the time - pit glass ?
more melted stone that is glassy and use this slab as a cookie sheet . :-)
4. cover the top with more fuel and then cap it off - perhaps air vent on the
side of the wind...

A reduction fire - and when cooled off it might have metal in the sheet...

Maybe.

Martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

  #25   Report Post  
Old June 24th 04, 04:19 AM
Eric Stevens
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:

On Thu, 10 Jun 2004 15:36:41 -0400, Yuri Kuchinsky wrote:
Copper Casting In America (Trevelyan)

Greetings, all,

Here's a brief review of a new volume about Native American
copper.

_________________

_Miskwabik, metal of ritual: metallurgy in precontact
Eastern North America_, Amelia M. Trevelyan.
Lexington : University Press of Kentucky, c2004.

("Miskwabik" is an Ojibwa word for "copper".)

Description:
Miskwabik, Metal of Ritual examines the thousands
of beautiful and intricate ritual works of art—from
ceremonial weaponry to delicate copper pendants
and ear ornaments—created in eastern North
America before the arrival of Europeans. The first
comprehensive examination of this 3,000-year-old
metallurgical tradition, the book provides unique
insight into the motivation of the artisans and the
significance of these objects, and highlights the
brilliance and sophistication of the early
civilizations of the Americas. Comparing the ritual
architecture and metallurgy of the original
Americans with the ethnological record, Amelia M.
Trevelyan begins to unravel the mystery of the
significance of the objects as well as their special
functions within the societies that created them. The
book includes dozens of striking color and black
and white photographs.

Amelia M. Trevelyan is Professor and Chair of Art
History at Principia College in Elsah, Illinois.

_________________

And here's a revealing quote from the above volume, p. 15.

"Metallurgical testing and observation indicate that native
copper was primarily cold-worked in precontact times and
forged rather than cast. However, because the temperatures
necessary for melting as well as smelting copper are
comparatively low, the latter was probably a technical
possibility."

So here we see the political bias in American archaeology
laid out for all the world to see.

1. She doesn't even mention any of the available scientific
evidence indicating that, in precontact times, much copper
was cast rather than cold-worked and forged.

It may simply be plain ignorance on her part, but we
shouldn't also discount a possibility that she's
deliberately excluding any evidence that is not in accord
with her anti-Native political bias.

In any case, the name Mallory (a qualified engineer, and the
leading researcher in this area) is not mentioned in her
bibliography at all.

2. Yet she admits these things "were probably a technical
possibility". How generous of her!

So here we see the sort of an anti-Native bigotry that is
still all too common within our professional archaeological
establishment. These folks really still live in the middle
ages!

What a dark snake-pit of racism and bigotry our academic
establishment is... This never ceases to amaze me, I must
say.

This is the Dumbing-Down Crew that is hard at work to deny
the cultural achievements of Native Americans.


Realize that casting is primarily a technique used for cheap mass
produced items.


With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.

It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.


You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.

Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.


Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.


Given that, it seems to me that your claims of bigotry by a art
historian are unfounded. If anything, the idea that the art objects
were produced by cold work makes them even more impressive
examples of the skill of the worker than if they were mere castings.


I think you are missing the point, and so too may be the art
historian. There seems to be evidence that some copper items were
cast. From what I have read, the cast products would not generally
qualify as 'art' and for that reason have understandably been ignored
by art historians.

But that said, casting pure copper is a bitch.


This from the guy who has just written that the task can be undertaken
by low-skilled workers?

Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.


Neither. The claim merely is that some copper items have been cast.




Eric Stevens


  #26   Report Post  
Old June 24th 04, 05:46 AM
Tom McDonald
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Eric Stevens wrote:

On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:


snip

Realize that casting is primarily a technique used for cheap mass
produced items.



With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.


Eric,

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques. (Note that I am
not saying that all the copper artifacts were so made; only that
casting was not necessary.) As for whether certain types of
tools and ornaments might be more easily made by casting, this
is only true if the technology for casting has been developed.
That is what is at issue.



It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.



You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.


Yes, especially wrt copper (see Gary's discussion of copper
casting problems below). So far as I can see at this point,
there isn't good evidence for such a period of development in
the archaeological record.

OTOH, at least for the Old Copper and Red Ochre complexes in
the Upper Great Lakes region, there don't seem to be many
well-documented sites from that period (ca. 3000-1000 BC); and
stratified sites are even more rare. Most of the copper
artifacts were surface finds, and many came from collectors
whose documentation of their finds generally ranged from fair to
non-existent.



Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.



Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.


Again, I don't know that that is true wrt copper, given the
difficulty the technique appears to have in creating strong,
high-quality results. OTOH, cold and hot working were known by
the Native peoples in the Great Lakes ares to produce that very
strong, high-quality result.

snip

But that said, casting pure copper is a bitch.



This from the guy who has just written that the task can be undertaken
by low-skilled workers?


Eric, I read that to mean that casting, in general (as with
iron, silver, bronze, gold, etc.) can be done by folks with
fewer skills than smiths. However, copper appears to present
particular problems with casting that are not so pronounced with
other metals, and which require higher skill levels than would
be required by those who cast other metals.

This should be taken into consideration along with the fact
that Great Lakes copper, and drift copper, don't need to be
smelted to use. In other areas, where smelting ore _is_
required, the technology for melting metal is a given; here, it
isn't.



Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.



Neither. The claim merely is that some copper items have been cast.


Eric, Yuri was making the claim that to say Indians of the
Great Lakes area didn't cast copper was to express bigotry
towards the First Nations of the area. Gary's argument flows
from Yuri's standard 'mainstreamers are racists' rap, with its
particular application in the cast vs. worked copper issue.

I'm still agnostic, and am reading up on the archaeological
references I can find. If you, or other folks, have suggestions
for reading, I'm all eyes.

BTW, I've just gotten Mallery's book (the 1979 version, revised
and extended by Mary Roberts Harrison). I've only skimmed a bit
of it, so I don't have an informed opinion on it yet. Will advise.

Tom McDonald
  #27   Report Post  
Old June 26th 04, 12:13 AM
Eric Stevens
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:

Eric Stevens wrote:

On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:


snip

Realize that casting is primarily a technique used for cheap mass
produced items.



With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.


Eric,

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.


This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.

(Note that I am
not saying that all the copper artifacts were so made; only that
casting was not necessary.)


That seems to be a different topic. Are you saying that even if they
were found to be cast, it wasn't necessary for them to be cast?

As for whether certain types of
tools and ornaments might be more easily made by casting, this
is only true if the technology for casting has been developed.
That is what is at issue.


I think you and I are approaching the question from opposite ends. You
seem to be saying that no artifacts can have been cast, in the absence
of direct evidence for casting techniques. I am saying that cast
artifacts are evidence for the existence of casting techniques, even
if direct evidence for such techniques is not known.



It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.



You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.


Yes, especially wrt copper (see Gary's discussion of copper
casting problems below). So far as I can see at this point,
there isn't good evidence for such a period of development in
the archaeological record.

OTOH, at least for the Old Copper and Red Ochre complexes in
the Upper Great Lakes region, there don't seem to be many
well-documented sites from that period (ca. 3000-1000 BC); and
stratified sites are even more rare. Most of the copper
artifacts were surface finds, and many came from collectors
whose documentation of their finds generally ranged from fair to
non-existent.



Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.



Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.


Again, I don't know that that is true wrt copper, given the
difficulty the technique appears to have in creating strong,
high-quality results. OTOH, cold and hot working were known by
the Native peoples in the Great Lakes ares to produce that very
strong, high-quality result.

snip

But that said, casting pure copper is a bitch.



This from the guy who has just written that the task can be undertaken
by low-skilled workers?


Eric, I read that to mean that casting, in general (as with
iron, silver, bronze, gold, etc.) can be done by folks with
fewer skills than smiths. However, copper appears to present
particular problems with casting that are not so pronounced with
other metals, and which require higher skill levels than would
be required by those who cast other metals.


I don't read 'low skilled' as meaning 'lower skilled'.


This should be taken into consideration along with the fact
that Great Lakes copper, and drift copper, don't need to be
smelted to use. In other areas, where smelting ore _is_
required, the technology for melting metal is a given; here, it
isn't.


There is a difference between 'smelted' as in refinining and 'melted'
as for casting. I am not aware of evidence for the for the former in
NA but there may be evidence for the latter in the form of cast
artifacts.




Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.



Neither. The claim merely is that some copper items have been cast.


Eric, Yuri was making the claim that to say Indians of the
Great Lakes area didn't cast copper was to express bigotry
towards the First Nations of the area. Gary's argument flows
from Yuri's standard 'mainstreamers are racists' rap, with its
particular application in the cast vs. worked copper issue.

I'm still agnostic, and am reading up on the archaeological
references I can find. If you, or other folks, have suggestions
for reading, I'm all eyes.

BTW, I've just gotten Mallery's book (the 1979 version, revised
and extended by Mary Roberts Harrison). I've only skimmed a bit
of it, so I don't have an informed opinion on it yet. Will advise.


Very much the curate's egg.




Eric Stevens

  #28   Report Post  
Old June 26th 04, 01:24 AM
Tom McDonald
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:


Eric Stevens wrote:


On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:


snip

Realize that casting is primarily a technique used for cheap mass
produced items.


With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.


Eric,

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.



This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.


Eric,

That could be. That's why I wrote the below.

My point here is that at least two researchers have done
experiments using only cold and hot working, without casting,
making all of the major types of artifacts found in the Great
Lakes area. This is not to say that some might not have been
cast. That's the issue. Contrary to what you write above, I
have not yet completed my own look into whether some might have
been cast. I'm not willing to take at face value reports of
research the originals of which I haven't yet found.



(Note that I am
not saying that all the copper artifacts were so made; only that
casting was not necessary.)



That seems to be a different topic. Are you saying that even if they
were found to be cast, it wasn't necessary for them to be cast?


It's the same topic. I was trying to avoid just this confusion
by stating frankly that the research I mentioned does not rule
out casting. And to your question, yes. I'm saying that it
seems to me at this point that both casting and smithing could
have produced the tools we find. The issue is whether both
techniques were used, and if so over what time period and what
places within the region.



As for whether certain types of
tools and ornaments might be more easily made by casting, this
is only true if the technology for casting has been developed.
That is what is at issue.



I think you and I are approaching the question from opposite ends. You
seem to be saying that no artifacts can have been cast, in the absence
of direct evidence for casting techniques. I am saying that cast
artifacts are evidence for the existence of casting techniques, even
if direct evidence for such techniques is not known.


You mistake my meaning. I am saying that casting and smithing
both could have been used. If there are artifacts that were
cast, then that fact should inform future archaeological work.

I'm not sure that you know this, but the main copper-using
cultures of the upper Great Lakes areas are very poorly
represented by habitation sites. In Wisconsin and the UP of
Michigan, there are only a few such sites that have been found
and studied from this period (Late Archaic to the transition to
Early Woodland--ca. 3-4000 to ca. 100 BC).

There are a great many sites with copper artifacts, but they
are mostly either surface finds, or are in mortuary contexts;
not where the ancient smiths/foundryfolk might have been
expected to ply their trades

I am less sanguine than you that old reports for which we have
only second-hand sources, and for which we don't know the
caveats and limitations of the researchers, can be accepted
uncritically in the face of nearly unanimous statement from
those who have studied the copper artifacts intensively that
they haven't found convincing evidence of casting. However, I
take offense at the suggestion that I've ruled out casting when
I am actually looking into the issue with an open mind.



It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.


You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.


Yes, especially wrt copper (see Gary's discussion of copper
casting problems below). So far as I can see at this point,
there isn't good evidence for such a period of development in
the archaeological record.

OTOH, at least for the Old Copper and Red Ochre complexes in
the Upper Great Lakes region, there don't seem to be many
well-documented sites from that period (ca. 3000-1000 BC); and
stratified sites are even more rare. Most of the copper
artifacts were surface finds, and many came from collectors
whose documentation of their finds generally ranged from fair to
non-existent.



Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.


Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.


Again, I don't know that that is true wrt copper, given the
difficulty the technique appears to have in creating strong,
high-quality results. OTOH, cold and hot working were known by
the Native peoples in the Great Lakes ares to produce that very
strong, high-quality result.

snip

But that said, casting pure copper is a bitch.


This from the guy who has just written that the task can be undertaken
by low-skilled workers?


Eric, I read that to mean that casting, in general (as with
iron, silver, bronze, gold, etc.) can be done by folks with
fewer skills than smiths. However, copper appears to present
particular problems with casting that are not so pronounced with
other metals, and which require higher skill levels than would
be required by those who cast other metals.



I don't read 'low skilled' as meaning 'lower skilled'.


Read it again. No mention of 'low skilled'. Merely that a
smith needs 'higher level of skill' than a foundryman. A
neurosurgeon may need a 'higher level of skill' than a
dermatologist. Does this make the dermatologist 'low skilled'?q


This should be taken into consideration along with the fact
that Great Lakes copper, and drift copper, don't need to be
smelted to use. In other areas, where smelting ore _is_
required, the technology for melting metal is a given; here, it
isn't.



There is a difference between 'smelted' as in refinining and 'melted'
as for casting. I am not aware of evidence for the for the former in
NA but there may be evidence for the latter in the form of cast
artifacts.


Of course smelting ore and melting for casting are different.
However, if one needs and has the technology for smelting,
melting for casting is not a technological leap. If one does
not need to smelt ore, then melting it for casting requires that
technological leap. The issue is whether that leap was made in
this case. If cast artifacts are found, then looking for
evidence of the development of that technology would be a higher
archaeological priority than it is now.




Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.


Neither. The claim merely is that some copper items have been cast.


Eric, Yuri was making the claim that to say Indians of the
Great Lakes area didn't cast copper was to express bigotry
towards the First Nations of the area. Gary's argument flows


from Yuri's standard 'mainstreamers are racists' rap, with its


particular application in the cast vs. worked copper issue.

I'm still agnostic, and am reading up on the archaeological
references I can find. If you, or other folks, have suggestions
for reading, I'm all eyes.

BTW, I've just gotten Mallery's book (the 1979 version, revised
and extended by Mary Roberts Harrison). I've only skimmed a bit
of it, so I don't have an informed opinion on it yet. Will advise.



Very much the curate's egg.


I'm not familiar with that. Will you explain for me?

Tom McDonald


  #29   Report Post  
Old June 26th 04, 06:07 AM
Eric Stevens
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Fri, 25 Jun 2004 19:24:15 -0500, Tom McDonald
wrote:

Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:


Eric Stevens wrote:


On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:

snip

Realize that casting is primarily a technique used for cheap mass
produced items.


With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.

Eric,

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.



This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.


Eric,

That could be. That's why I wrote the below.

My point here is that at least two researchers have done
experiments using only cold and hot working, without casting,
making all of the major types of artifacts found in the Great
Lakes area. This is not to say that some might not have been
cast. That's the issue. Contrary to what you write above, I
have not yet completed my own look into whether some might have
been cast. I'm not willing to take at face value reports of
research the originals of which I haven't yet found.


Fair enough. You may remember that some years ago I reported that I
had tried to track down Mallery's papers (left to the Smithsonian on
his death) to obtain copies of the originals upon which he relied, but
all the papers seem to have vanished into a black hole. It might be
worth another try.



(Note that I am
not saying that all the copper artifacts were so made; only that
casting was not necessary.)



That seems to be a different topic. Are you saying that even if they
were found to be cast, it wasn't necessary for them to be cast?


It's the same topic. I was trying to avoid just this confusion
by stating frankly that the research I mentioned does not rule
out casting. And to your question, yes. I'm saying that it
seems to me at this point that both casting and smithing could
have produced the tools we find.


Only if your assessment is based on simplistic visual examination.
Appropriate metallurgical tests are unambiguous.

The issue is whether both
techniques were used, and if so over what time period and what
places within the region.



As for whether certain types of
tools and ornaments might be more easily made by casting, this
is only true if the technology for casting has been developed.
That is what is at issue.



I think you and I are approaching the question from opposite ends. You
seem to be saying that no artifacts can have been cast, in the absence
of direct evidence for casting techniques. I am saying that cast
artifacts are evidence for the existence of casting techniques, even
if direct evidence for such techniques is not known.


You mistake my meaning. I am saying that casting and smithing
both could have been used. If there are artifacts that were
cast, then that fact should inform future archaeological work.

I'm not sure that you know this, but the main copper-using
cultures of the upper Great Lakes areas are very poorly
represented by habitation sites. In Wisconsin and the UP of
Michigan, there are only a few such sites that have been found
and studied from this period (Late Archaic to the transition to
Early Woodland--ca. 3-4000 to ca. 100 BC).

There are a great many sites with copper artifacts, but they
are mostly either surface finds, or are in mortuary contexts;
not where the ancient smiths/foundryfolk might have been
expected to ply their trades

I am less sanguine than you that old reports for which we have
only second-hand sources, and for which we don't know the
caveats and limitations of the researchers, can be accepted
uncritically in the face of nearly unanimous statement from
those who have studied the copper artifacts intensively that
they haven't found convincing evidence of casting. However, I
take offense at the suggestion that I've ruled out casting when
I am actually looking into the issue with an open mind.


I didn't say, or even imply, that you have unconditionally ruled out
the possibility of cast artifacts.



It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.


You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.

Yes, especially wrt copper (see Gary's discussion of copper
casting problems below). So far as I can see at this point,
there isn't good evidence for such a period of development in
the archaeological record.

OTOH, at least for the Old Copper and Red Ochre complexes in
the Upper Great Lakes region, there don't seem to be many
well-documented sites from that period (ca. 3000-1000 BC); and
stratified sites are even more rare. Most of the copper
artifacts were surface finds, and many came from collectors
whose documentation of their finds generally ranged from fair to
non-existent.



Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.


Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.

Again, I don't know that that is true wrt copper, given the
difficulty the technique appears to have in creating strong,
high-quality results. OTOH, cold and hot working were known by
the Native peoples in the Great Lakes ares to produce that very
strong, high-quality result.

snip

But that said, casting pure copper is a bitch.


This from the guy who has just written that the task can be undertaken
by low-skilled workers?

Eric, I read that to mean that casting, in general (as with
iron, silver, bronze, gold, etc.) can be done by folks with
fewer skills than smiths. However, copper appears to present
particular problems with casting that are not so pronounced with
other metals, and which require higher skill levels than would
be required by those who cast other metals.



I don't read 'low skilled' as meaning 'lower skilled'.


Read it again. No mention of 'low skilled'.


Gary Coffman originally wrote of casting "It allows relatively low
skilled workers to produce ... " and it was to this which I originally
repsonded. My point was that casting is not a low skilled technique.

Merely that a
smith needs 'higher level of skill' than a foundryman. A
neurosurgeon may need a 'higher level of skill' than a
dermatologist. Does this make the dermatologist 'low skilled'?q


But is the fundamental proposition correct, that a dermatologist is
necessarily of lower skill than a neurosurgeon? My observation is that
while the disciplines are different, the skill levels are equally high
in each.


This should be taken into consideration along with the fact
that Great Lakes copper, and drift copper, don't need to be
smelted to use. In other areas, where smelting ore _is_
required, the technology for melting metal is a given; here, it
isn't.



There is a difference between 'smelted' as in refinining and 'melted'
as for casting. I am not aware of evidence for the for the former in
NA but there may be evidence for the latter in the form of cast
artifacts.


Of course smelting ore and melting for casting are different.
However, if one needs and has the technology for smelting,
melting for casting is not a technological leap. If one does
not need to smelt ore, then melting it for casting requires that
technological leap. The issue is whether that leap was made in
this case.


The discovery of either smelting or melting would initially be
accidental. I could think of circumstances in which melting could
still occur when working with pure meteoric copper.

If cast artifacts are found, then looking for
evidence of the development of that technology would be a higher
archaeological priority than it is now.


I do not share your certainty. Cast artifacts do seem to have been
found. I am not aware that the reports cited by Mallery have been
followed up in any way. As far as I can tell, nobody has even followed
them up for the purpose of showing that they were wrong or that
Mallery has misinterpreted them. The whole subject seems to have been
treated as a non-issue.




Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.


Neither. The claim merely is that some copper items have been cast.

Eric, Yuri was making the claim that to say Indians of the
Great Lakes area didn't cast copper was to express bigotry
towards the First Nations of the area. Gary's argument flows


from Yuri's standard 'mainstreamers are racists' rap, with its


particular application in the cast vs. worked copper issue.

I'm still agnostic, and am reading up on the archaeological
references I can find. If you, or other folks, have suggestions
for reading, I'm all eyes.

BTW, I've just gotten Mallery's book (the 1979 version, revised
and extended by Mary Roberts Harrison). I've only skimmed a bit
of it, so I don't have an informed opinion on it yet. Will advise.



Very much the curate's egg.


I'm not familiar with that. Will you explain for me?

A 19th century 'Punch' cartoon. The very new curate is having
breakfast with his bishop and finds the boiled egg he has been served
is rotten. The curate lacks the courage to complain about the bishop's
breakfast fodder but the expression on his face alerts the bishop to
the fact that all is not well. The bishop then asks ' ... and how is
your egg?' The curate still too nervous to say the egg is rotten
replies "Parts of it are excellent, my lord". That last is the comment
I applied to Mallery's book.



Eric Stevens

  #30   Report Post  
Old June 26th 04, 06:13 AM
Eric Stevens
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Sat, 26 Jun 2004 17:07:04 +1200, Eric Stevens
wrote:

Very much the curate's egg.


I'm not familiar with that. Will you explain for me?

A 19th century 'Punch' cartoon. The very new curate is having
breakfast with his bishop and finds the boiled egg he has been served
is rotten. The curate lacks the courage to complain about the bishop's
breakfast fodder but the expression on his face alerts the bishop to
the fact that all is not well. The bishop then asks ' ... and how is
your egg?' The curate still too nervous to say the egg is rotten
replies "Parts of it are excellent, my lord". That last is the comment
I applied to Mallery's book.


http://www.quinion.com/words/qa/qa-cur1.htm gives an even better
explanation.




Eric Stevens



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Determining Geologic Sources of Native American Copper Yuri Kuchinsky Metalworking 92 June 23rd 04 05:21 PM
Copper plating Dan Caster Metalworking 5 July 24th 03 01:04 PM


All times are GMT +1. The time now is 04:11 AM.

Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright ©2004-2017 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017