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Karl Carvalho

Japanese Alloys

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I've moved over to another thread so as not to dilute Mokume, a really important topic and deserved of it's own thread (as is this one).

Japanese alloys are the basis of the unique metal arts of Japan. Understanding their compositions, properties and patinas are key to their use.

 

Aloha Ford,

 

I've actually been lead to believe that Kuromido has 3% As in it.

 

Thanks for the quick response. :huh: This is what I am filtering through (not taking sides, just reporting).

1) After showing the TUFA chart to Gene, his comment was, "Hey, that looks like something I worked on in the 70s/80s(?). He was not in agreement with 3% As. Coincidentally, the chart lists 100 parts Cu and 3 parts As.

2) The charts in Sugimuri's text call for 97% Cu/3% As.

 

Karl

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Guest ford hallam

Hi Karl,

 

I've got kuromido from a company in Tokyo called Komokin, they specify 3% As in their technical data sheets. They make their own alloys so I imagine they know what's in it! :( I don't know if anyone else produces the stuff being as it has such a specialist application.

 

Ford :)

 

P.S.

Sugimori's book, at least the original version, is actually a rough translation of the only really relevant reference he cites in his bibliography; "Colouring technique of Metalwork" by Yutaka Nagano and Kenji Io.

I actually studied with Mr Io for a couple of weeks, he wasn't to impressed with his (!?) english edition ;) particularly as he only found out after it had been published :huh:

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I've moved over to another thread so as not to dilute Mokume, a really important topic and deserved of it's own thread (as is this one).

Japanese alloys are the basis of the unique metal arts of Japan. Understanding their compositions, properties and patinas are key to their use.

 

Aloha Ford,

Thanks for the quick response. :huh: This is what I am filtering through (not taking sides, just reporting).

1) After showing the TUFA chart to Gene, his comment was, "Hey, that looks like something I worked on in the 70s/80s(?). He was not in agreement with 3% As. Coincidentally, the chart lists 100 parts Cu and 3 parts As.

2) The charts in Sugimuri's text call for 97% Cu/3% As.

 

Karl

 

The "Parts" system is a little funky in my mind. I am not that used to it. When you add another alloy composed of parts as a whole part rather than breaking it down into its constituent metals, it gets more confusing. I convert everything into percentages. 3parts and 100parts comes out to 2.91 percent rather than three percent. Will that difference of one tenth of a percent make a difference? probably not. But it is good to be aware that there is a difference.

patrick

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I threw a sample of some rocks I picked up at an abandoned copper mine into a crucible (after roasting, with flux) and gave it a test blast in the furnace today, got a small amount of copper mixed with an equal amount of iron - much of which came from prills of iron left in the slag on the crucible wall from making steel.

I'll try again tomorrow after I clean out the crucible better! :angry:

From reading 1800s smelting texts, it looks like a magnetic iron/copper mixture or alloy is one of the expected products of copper smelting, and one is supposed to remelt the alloy and oxidize off the iron. There is a lot of variety in copper smelting methods, compared to iron making, in general several refining steps seem to be called for in all the methods.

post-1173-1181449431.jpg

 

Here you can see the iron dots in a copper matrix:

post-1173-1181449443.jpg

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I threw a sample of some rocks I picked up at an abandoned copper mine into a crucible (after roasting, with flux) and gave it a test blast in the furnace today, got a small amount of copper mixed with an equal amount of iron - much of which came from prills of iron left in the slag on the crucible wall from making steel.

I'll try again tomorrow after I clean out the crucible better! :angry:

From reading 1800s smelting texts, it looks like a magnetic iron/copper mixture or alloy is one of the expected products of copper smelting, and one is supposed to remelt the alloy and oxidize off the iron. There is a lot of variety in copper smelting methods, compared to iron making, in general several refining steps seem to be called for in all the methods.

post-1173-1181449431.jpg

 

Here you can see the iron dots in a copper matrix:

post-1173-1181449443.jpg

 

Very promising. What type of ore is it and what mine did you go to? Sulphide ores require secondary processing and are the most common for industrial mines. The primary ore contains iron so the iron mix sounds right. secondary Oxide and carbonate ores can be reduced directly to copper I think. I am hoping to emulate the older more primitive methods and use secondary Carbonate ores like Malachite or oxide ore cuprites and such. I have been looking for references for ancient Japanese Copper smelting, but that is not yielding much. So I don't know anything about the ore they used or the specific technique. California is a geologically diverse place on par with Japans Geology. What ever it is I can probably find the same family of ore either here or Nevada. I just need more information!

In your samples do you think it would be possible to simply melt the copper out?

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Hi folks,

 

there is a nice book on native japanese copper production. It`s the "Kodo Zuroku" (originaly printed in Japan 1801) republished by the Burndy Library in 1983 with an Essay of Cyril Stanley Smith. ( there are nice woodcuts by Tokei in that book.) Some years ago there was an online-version - now removed from their server.

The Japanese methode is Namban, that means it is derivede from european methods. In this case it comes from a german origin :angry: - Das Seigern- an old method for copper refining. Take a look on Agricola for that.

 

And a shord word on safety: the smoke produced by smelting raw copper contains larger amounts of arsenic, lead and antimony. :D Just be careful.

 

Berlin Karl

 

Ps. I has just read on live chat and stuff. I love the idea. :)

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Aloha

 

Patrick

Two things:

1) Are you talking about refining copper from the gemstone malachite? Is that economically feasible? I have a friend who owns some mines (turquoise among others) with some of his buddies out of Carson City, Nev. He is pretty well connected to the gem trade. I can ask about copper mines.

Also, the Univ. of Hawaii has strong ties to Japan. I can ask around regarding any visiting Japanese geologists?

2) Regarding your comment over in mokume on As content - "the 1 percent I see cited in many sources on Mokume gane." Not trying to disrupt the Force, but can you recall some of those sources?

 

Karl

That must be some impressive German Search Engine you drive. What's the secret? And, don't forget, for live chats, I'm in my own time zone.

 

Karl

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FYI: Cape Town, & Berlin are 12 hours ahead of Honolulu. I am 7 hours behind Berlin and Cape Town, and 5 hours ahead of Honolulu. TCP has members farther east in Ukraine, Russia and Moldova, and a few further west in China, Australia and New Zealand.

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Guest ford hallam

Hi Janel,

 

I have a feeling that none of us keeps "normal" hours anyway :) .

 

Aloha Karl,

 

this idea that seems to be developing here about the possibility of smelting and refining one's own copper is very exciting and if anyone does follow that route I for one will be very interested to follow their progress. Having said all that it may be a little less complicated to start with the sort of metallic copper samples that can be bought at rock and gem shows. I have a piece I've been meaning to smelt for some time, perhaps now would be good. It has a few bits of grit etc on the surface but I don't think this should pose too much of a problem. I'll report back on this prospect asap.

 

cheers, Ford

 

Oh,and I imagine Berlin Karl has a search engine that makes "voorsprung durch technik" :D:angry:

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What type of ore is it and what mine did you go to?

 

I think carbonate/oxide for the most part, there were not huge volumes of sulfur fumes generated during the roasting. The mine was a smallish operation out in the Mojave desert, probably late 19th to early 20th century.

 

So I don't know anything about the ore they used or the specific technique.

 

Me either, but charcoal stack furnaces are pretty much ubiquitous in metal making around the world, so using one of them would be near the mark.

 

In your samples do you think it would be possible to simply melt the copper out?

 

No, there is no native metal to melt in these rocks. Volcanic areas tend to be rather oxidizing, I think.

 

there is a nice book on native japanese copper production. It`s the "Kodo Zuroku"

 

cool, do you have that title in kanji? B)

 

The Japanese methode is Namban, that means it is derivede from european methods

 

Although when they were casting the Nara Buddha in AD750, presumably the copper in the bronze was refined using techniques derived from China:

http://en.wikipedia.org/wiki/T%C5%8Ddai-ji

 

the smoke produced by smelting raw copper contains larger amounts of arsenic, lead and antimony. Just be careful

 

Don’t try this at home, kids! :)

 

Are you talking about refining copper from the gemstone malachite? Is that economically feasible?

 

I’ve been doing quite a bit of home smelting, and I can assure you it is NEVER economically feasible! :angry:

But yes, malachite is an ore of copper, and as such the non-gem grades need to be smelted.

If you need me to go to Carson City to high-grade the stuff for you, I can do that. :D

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Hi Jeff, fellas,

 

I've just been doing a little poking around on the net seeing what was out there regarding copper ores etc.

 

It would seem that the ore you smelted Jeff, is most likely Chalcopyrite, CuFeS2 and when pure contains 34.5% copper. The ore with the highest yield of copper is Cuprite, Cu2O with 88.8% copper in it's pure form. Oxides of copper are also easier to refine, apparently.

 

It is still possible to get hold of samples of actual metallic copper which would probably be the earliest form in which man utilized the metal. I've attached some images of metallic copper. I have a similar sample I will smelt sometime this week. Then I'll forge it out and patinate it. It ought to look just like old Japanese yamagane.

 

 

 

well, thats my addition to the pot, or should I say cruicible :angry:

 

regards, Ford

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1. cool, do you have that title in kanji? B)

 

2. Although when they were casting the Nara Buddha in AD750, presumably the copper in the bronze was refined using techniques derived from China

 

3. Don’t try this at home, kids! :)

 

Hi Jeff,

 

1. No, I didnt find the right keys on my computer but there are some kanji in that book. But even the translator has had some problems with it. :angry:

 

2. you are right Jeff, of course the methods changed somewhat between the casting of the Nara Daibutsu (751) and the methods used in Edo period (1800), even in Japan. :D

 

3. Just do not inhale much of the smoke. Heavy metal poisening dosnt mean only enjoying loud music and getting a wry neck from headbanging. B)

 

Karl

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Hi folks,

 

there is a nice book on native japanese copper production. It`s the "Kodo Zuroku" (originaly printed in Japan 1801) republished by the Burndy Library in 1983 with an Essay of Cyril Stanley Smith. ( there are nice woodcuts by Tokei in that book.) Some years ago there was an online-version - now removed from their server.

The Japanese methode is Namban, that means it is derivede from european methods. In this case it comes from a german origin :angry: - Das Seigern- an old method for copper refining. Take a look on Agricola for that.

 

And a shord word on safety: the smoke produced by smelting raw copper contains larger amounts of arsenic, lead and antimony. :D Just be careful.

 

Berlin Karl

 

Ps. I has just read on live chat and stuff. I love the idea. :)

 

Thanks for the book reference! I have been looking and looking. BTW Amazon had three copies I just ordered one of them. Also there is a book called "De Re Metallica, by Georgius Argicola". Originally published in 1556 and is considered to be one of the earliest known detailed books on Copper mining and smelting. That is also on Amazon for very reasonable prices.

Patrick

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Hi Jeff,

I actually meant in your fired sample. Could that copper be melted out from around the iron bits?

Malachite while there is gem grade material there is also a lot more non gem grade material that is considerably less in cost. The same goes for the other azurite and turquoise. The trick is finding that pile of rejected low value mineral and transporting it with out driving the cost way up or getting gouged by the dealer. It would be best to find abandoned sources like you did. I have a heavy California geology background and I am an avid Rock Hound. The question for me is not how to get the ore, but which ore I really want to use. although I don't really want to use a Suphide ore like industy (Chalcopyrite) If possible I would like to make it as the Japanese did, but just smelting it myself with any workable technique would still be satisfying.

I eagerly await the arrival those books!

Patrick

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Hi Ford,

Native copper is certainly convenient, but I personally have a problem with destroying Specimens like the once you have pictured. Native copper is relatively rare and very collectible. In nature it is short lived because it converts to all those secondary ore minerals we are discussing. If the sample shows good faceting and structure I could not bring myself to melt it. If the samples were very low grade damaged and such I suppose it would be ok, but I would hate to see a trend where they were all purchased just to be melted down. Rather like melting antique sword fittings to get a cheap source of Shakudo. I would much rather Analyze and replicate than destroy things of importance and beauty. A concept that I know you can appreciate. Not to imply that you should not do what you like with your sample. I just thought I would share the Rock hound persepective.

Edited to add, It looks like native copper is quite feasible and the better specimens would be mostly protected by price point. Price is relative though.

Patrick

 

Here are some other interesting tid bits on copper.

Copper in the middle ages

http://www.unr.edu/sb204/geology/copper2.html

Then there is this do it your self website. he has not had much sucess, but I don't think his ore is good. It is still an interesting read though.

http://www.cyphertext.net/~gfish/smelting.html

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Being in the Great Lakes area,there are numerous locations to get native copper without destroying a good fan shaped specimen. most any tourist stop in the area has michigan copper "nuggets", you do pay a premium price for them though. there are many rock shops online also which supply raw copper in many forms. link to minersl shop with copper nuggets.

 

House of Onyx

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Being in the Great Lakes area,there are numerous locations to get native copper without destroying a good fan shaped specimen. most any tourist stop in the area has michigan copper "nuggets", you do pay a premium price for them though. there are many rock shops online also which supply raw copper in many forms. link to minersl shop with copper nuggets.

 

Their specimens have already been altered and for me that destroys there specimen value. The price does not look that bad for the nugget shown. This level of native copper is most likly what Ford was talking about, but the pictures he showed are specimens that I would covet not melt hence the comment. Good link thanks.

Edited to add,

I shopped around for Native copper and found no shortage of Poor quality nuggets. If the source can be trusted it looks like Native copper in this form is not much more expensive that refined copper. Ebay has a number of sellers and the Michigan area has no shortage of sellers. I don't know if I trust all the sources though. Native seems to be interpreted by some has having been mined locally rather than indicating being unrefined.

patrick

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Aloha Guys,

 

I am sitting on the sidelines (not really; I am running from room to room using the home network while my new computer :angry: is being set up), following with extreme interest.

Question: In light of the coming changes to Metalwork, did I do right to call this thread Japanese Alloys, or should it be Yamagane (it might be too late to change)? Also keeping in mind that yamagane is probably the base of the copper alloys.

 

Karl

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Question: In light of the coming changes to Metalwork, did I do right to call this thread Japanese Alloys, or should it be Yamagane (it might be too late to change)? Also keeping in mind that yamagane is probably the base of the copper alloys.

Karl

 

Good evening Karl,

 

it might be a good idea to call this a Yama-gane thread. It would be extremly difficult to discuss all japanese alloy in one thread only. :angry: (One can writte metalographic treatises on each of them, and these are not the only interesting metals in the world :D ).

 

Berlin Karl

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“Japanese Alloys” would be a good sub-forum.

 

 

Could that copper be melted out from around the iron bits?

 

Yes, I was able to remove most of the iron by pulling it out of the molten copper.

I think the rock I was working had a lot of magnetite or similar iron oxide along with the copper, I did a magnet sweep of the crushed ore before melting the second batch of ore, picked up a lot of material, and got a more coppery, less magnetic ingot out of the smelt – sweeping the old iron prills off the sides of the crucible probably helped, but there was still a lot of iron in the ore.

 

I melted my two wafers of copper/iron mixture/alloy and raked out the iron lumps in one heat, re-melted to oxidize it in another heat and ended up with 85 grams of non-magnetic copper. After about a day of labor, 40ish bucks of propane and electricity, and a couple pounds of rocks from the desert (that’s for the economists out there) :D .

I will remelt this lump one more time to deoxidize the metal before I try to turn it into sheet.

Do you get the same arsenic etc. with native copper, as with oxide ore veins?

 

De Re Metallica is on line, too –

HTML -

http://technology.infomine.com/historymine...ica/drm/toc.htm

 

and PDF, of 129.46 MB –

http://archimedes.mpiwg-berlin.mpg.de//doc...cola_met_en.pdf

 

 

post-1173-1181521433.jpg

post-1173-1181521442.jpg

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“Japanese Alloys” would be a good sub-forum.

Yes, I was able to remove most of the iron by pulling it out of the molten copper.

I think the rock I was working had a lot of magnetite or similar iron oxide along with the copper, I did a magnet sweep of the crushed ore before melting the second batch of ore, picked up a lot of material, and got a more coppery, less magnetic ingot out of the smelt – sweeping the old iron prills off the sides of the crucible probably helped, but there was still a lot of iron in the ore.

 

I melted my two wafers of copper/iron mixture/alloy and raked out the iron lumps in one heat, re-melted to oxidize it in another heat and ended up with 85 grams of non-magnetic copper. After about a day of labor, 40ish bucks of propane and electricity, and a couple pounds of rocks from the desert (that’s for the economists out there) :D .

I will remelt this lump one more time to deoxidize the metal before I try to turn it into sheet.

Do you get the same arsenic etc. with native copper, as with oxide ore veins?

 

De Re Metallica is on line, too –

HTML -

http://technology.infomine.com/historymine...ica/drm/toc.htm

 

and PDF, of 129.46 MB –

http://archimedes.mpiwg-berlin.mpg.de//doc...cola_met_en.pdf

post-1173-1181521433.jpg

post-1173-1181521442.jpg

 

Well I already ordered the book, but it was only $12.

The content of the other metals is going to be unique to the formation it came from. I would guess that the Native copper May be just as contaminated as the ore. I think it is going to vary alot from deposit to deposit.

Very nice blob of copper there. How do you plan to deoxidize it?

patrick

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Whoa, I just noticed that PDF file english translation of "De Re Metallica" was done by U.S. Prezident Herbert Hoover!

I will deox by melting with a reducing flux and a bunch of charcoal on top, or by stirring the metal with a green branch, depending on what melting container I use - a low-sided jeweler's melting dish might get a little exciting with the green branch method, what with the steam-induced splattering of molten metal everywhere... I'm open to suggestions, though - all my deoxidating has been of the ferrous variety lately, I might not be going by the straightest path in this non-ferrous jungle.

:D

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Fun stuff. A few years ago I spent time poking around abandoned copper mines here in Vermont hoping to stumble over some fabled "shirome" :D No such luck. Did find some cool looking slag chunks.

 

It might be worth exploring Mexican sources for copper, which is where, I think, that bit that Ford has came from. Very active cottage raising activity there. Should be much to learn from local smelters, if they are still active.

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hoping to stumble over some fabled "shirome" :D

 

Aloha Jim,

 

Good to see you here. :) Is that material you refer to the "same" as azuki-shiromi (as mentioned in Sugimori's text)? A by-product? I seem to remember a recent member (a former student of Yotkov), who is a metals worker from Mexico. Can't recall his name while posting this. Perhaps we can reach out and convince him to go on a scavenger hunt?

With all the metric tons of copper exchanging hands in the world, you would think we could lay our hands on a few pounds; well, a few kilos; well,....... :o

 

KC

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Aloha Karl, and thanks.

 

Hah,hah,hah! "the same"? A loaded question if ever I did see. Ford first mentioned the mysterious substance to me I think when I visited him in Chippenham in 1997. Without consulting my notes, I forget the context or what he had to say exactly. :D (sorry Ford!) It may have been that when added as a constituent of shakudo that it contributed to the attainment of purplish black. This was what Toshimasa maintained, and I can only deduce his veracity as he indeed did have that lustrous purple black in certain pieces. He had the only actual specimen of shirome I have seen or heard tell of. I recall it being about the size of an American softball, looking metallic and crystalline.

 

According to Gowland, shirome is a by-product of the separation of silver from copper by liquating with lead. He states the constituents as copper, arsenic, lead & antimony. It would seem, that as a by-product, it would vary according to local native ore make-up. It's primary use as an alloy addition seems to have been for the hardening of coinage and to enhance the patina in karakane bronze.

 

Apparently, again according to Gowland, the process of separating silver from copper by liquation with lead (namban fuki) was introduced by the Portuguese who he claims got the process from the Germans where it was known as "Das Saigern". Gowland says the Japanese adopted the basic principles but added their own methods to make the process more efficient and workable on a small scale, with a quantity as small as 80 lbs of copper being treatable. Again, the real goal was to separate the silver from the copper.

 

At any rate it all is pretty academic unless you've got some of this shirome hanging around and want to throw it in the pot! When Toshimasa showed me his chunk I asked where there was a source, and he thought I was asking about making it. He laughed so hard I was too embarrassed to explain that I just wanted some, not to make it.

Anyway, after poking around mines in Vermont (and Arizona) it sunk in that no doubt it was a product of a process not used in those places. I lost the scent, but had fun. Sometimes the search is just as good as the find.

 

It's very cool that there is this much interest in smelting and related basic processes. I'll see what "metalsmith"(feminine, Mexican, member) says about Mexican copper and process. Time is at a premium these days so I might not get back immediately.

 

Stay on the trail! Jim

 

there is a nice book on native japanese copper production. It`s the "Kodo Zuroku" (originaly printed in Japan 1801) republished by the Burndy Library in 1983 with an Essay of Cyril Stanley Smith. ( there are nice woodcuts by Tokei in that book.) Some years ago there was an online-version - now removed from their server.

 

 

Berlin Karl

 

Thanks Berlin Karl! I ordered one also. :o

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