Gary Coffman 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:
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.

Exactly, and further, skill alone isn't sufficient to make sound
castings of pure copper. The proper equipment is also required.
Specifically, an inert atmosphere furnace. That technology
didn't exist until the late 19th century.

Gary

Hi, Gary,

Here you seem to be implying that copper casting wasn't done
in the ancient world at all.

You couldn't be more wrong, my friend... Sure seems to me
like you're not very knowledgeable about the ways that the
ancient peoples worked with metals.

And this implies that your general knowledge about
metalworking is rather deficient, since you've reached the
above conclusion based on it, rather than on your
familiarity with archaeological evidence.

So here's some archaeological evidence for a change, that
refutes your speculations about the ancient peoples not
casting pure copper.

[quotes]

INDIA

http://www.hindunet.org/hindu_histor.../artefacts.htm

Melting of native copper was done by putting the regulus
[lump of copper] over furnace or fire in a crucible and then
casting it.


IRELAND

Copper and Tin Mining in Ireland in the Bronze Age
http://www.thecelticplanet.com/mining.htm

It is estimated that in the early Bronze Age in Ireland, not
more than 14% of artifacts were of bronze. The remainder
were made from copper only


SOUTHERN SIBERIA

http://faculty.web.waseda.ac.jp/yukis/sougen13.mei.html

Intriguingly, the majority of cauldrons recovered in
southern Siberia were also made of pure copper instead of
tin bronze. According to Bogdanova-Berezobskaya (1963: 136,
153), among the twenty cauldrons analyzed, thirteen are pure
copper, five arsenical copper (As 1-1.5%), one tin bronze,
and one Cu-Sn-Pb alloy.

[the date range above seems to be 7th-8th centuries BC]


http://www.thecopperlink.com/product...i-of_index.php

the oldest artefacts are not made of copper tin alloys, they
are made of pure copper.

Some examples of early smelted copper artefacts:

-- 3800 BC Spatula, Chisel, Awl - Iran (Yahya)
-- 3500 BC Flat axe - Egypt

[end quotes]

So it's never too late to educate yourself about such
things, Gary.

Best 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