15th November 2013, 12:55 PM | #1 |
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Damascus or damascening?
Colleagues,
This beautiful indo-persian saber was recently sol. There sems to be a marked difference of opinion on the technique: is it a true mechanical damascus or just a superficial damascening ( etching?) I am putting a bunch of close-up pics for you to express your opinion. The input from professional bladesmiths is especially welcoe. Thanks. |
15th November 2013, 04:55 PM | #2 |
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Clearly acid etch - imitation pattern applied on the surface.
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15th November 2013, 05:07 PM | #3 |
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Looks etched to me as well.
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16th November 2013, 04:33 AM | #4 |
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Yep. I agree. However "damascening" means basically something like koftgari, but a little thicker, and usually in script.
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17th November 2013, 06:18 AM | #5 |
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Thanks to all.
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17th November 2013, 09:09 PM | #6 |
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Hello Ibrahiim,
It seems to me, that the text you have sent, is not written by you, but by Ann Feuerbach, and if this is correct why do you not give her credit for it? One thing is to qwote a short text, and give the author credit for it, I think it is quite something else, to quote a whole article, screen page after screen page, and not even write who the author is. It is beyound me, and I am sure it is not in the spirit of the forum. Jens |
18th November 2013, 02:13 AM | #7 | |
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Quote:
http://www.academia.edu/397355/Cruci...st_2_000_Years |
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18th November 2013, 02:16 PM | #8 | |
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Article by Dr Ann Feuerbach.
Quote:
Salaams Jens Nordlunde Do you know something? I couldn't figure where I had copied that detail from though I thought it may have come from our own library and it was a while ago that I was researching the subject of wootz... but as you quite rightly point out I ought to have credited it to the very excellent work done by Dr Ann Feuerbach whose name, is as it happens, is very prominently displayed in the article. How anyone could think that the article was mine is very flattering ... It is well worth reading in context with this thread. Apologies to Dr Ann Feuerbach and Forum for omitting the author. I stand corrected and reitterate the detail as http://www.academia.edu/397355/Cruci...st_2_000_Years by Dr Ann Feuerbach. Regards, Ibrahiim al Balooshi. |
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18th November 2013, 05:00 PM | #9 | |
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Quote:
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23rd November 2013, 06:57 PM | #10 |
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clarification please.
I have never been clear about the difference between damascus steel , as in gun barrels where the distinctive pattern emerges from bars of iron of different carbon content which are twisted and forged together, and wootz or crucible steel where the implication is that the pattern is somehow inheirent in the structure of the steel itself . And having read the Anne Feurbach piece I am not any clearer . Surely the differing carbon content of the steel depends on local conditions in the crucible when organic matter is added in order to increase the carbon content of the steel . But I cant see how this results in any pattern , other than that the resulting lump may have odd mixtures of metal of differing carbon content. Surely the patterning only emerges subsequently when the lump is beaten, folded or twisted in order to consolidate the steel and any diserneble pattern is the result of this initial forging. Exported as a ingot for the production of a sword blade one can see how this patterning is passed on to the blade , but also how a more regular , more controlled pattern can also emerge from the way the steel is intentionally manipulated while the blade is forged. Im sure others like me would appreciate some expert clarification.
There seem to be some ingots of suposedly old wootz steel around at the moment . Described as Indo Persian , in the form of fairly regular balls about 20 centimeters diameter and about 1 kilo weight. It would be interesting to section one and etch to see how any pattern , if it exists at all , compares with finished blades . Can't post any images as these are currently for sale. Last edited by Raf; 24th November 2013 at 02:15 PM. |
25th November 2013, 12:30 AM | #11 |
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I expect the damascus & wootz experts can make this clear.
I am a metallurgist knowing only what I have read, concerning wootz, but with a couple of years practice in the field of metallurgy. In a damascus shotgun barrel the high carbon steel - and I would guess this maybe 0.6 - 1.0% carbon - will "etch", or corrode, faster than will low carbon wrought iron, this latter being no more than 0.1% carbon. Bars of high carbon steel and low carbon wrought iron are twisted and forge welded together. As forged and polished, such a barrel would show only the faintest pattern, if any. In manufacture the polished and degreased barrel is coated with a range of corrosive, and amazingly poisonous, chemicals which corrode/rust/whatever the high carbon steel much more than they do the low carbon iron. Hence, a pattern. Wootz is different. So, well, I know no other way about this than to give a small lesson in metallurgy. At room temperature, annealed steel can have up to about 0.8% carbon in the form of what is called "pearlite". This is a phase consisting of layers of more or less pure iron and iron carbide, Fe3C. (It is called "pearlite" because of an observation made by some guy a century or so past, nothing to do with current subject) If you make steel with more than 0.8% carbon, all that carbon above 0.8% will be in the form of chunks of iron carbide, Fe3C. The carbide is hard but this hardness does not show up in a conventional Rockwell hardness test, which is a matter of making a dent with a diamond, and a specified load of a couple hundred pounds. Big dent = soft, little dent means hard. When you put wootz on a Rockwell hardness machine, that machine is mostly just measuring the hardness of the pearlite matrix. Iron carbide is extremely hard, and brittle. It is good to have some in steel for wear resistance. Wootz can easily be 1.7% carbon, so there is lots of iron carbide around. And yes, iron carbide does not etch as readily as does pearlite. For reasons best explained by Anne Feurbach, this iron carbide in wootz is present as bands. So, if one polishes and then etches wootz, these bands of very hard iron carbide will be visible as a light pattern within a darker pearlite matrix. If the smith does his job artistically, he can make these bands into various patterns, e.g. Muhamed's Ladder, or the Rose. I am assuming the wootz has not been hardened. To make a sword one normally heat treats, or hardens, common steel. Wootz is a bit different, as even if it is not very hard (a modern custom knife might be Rockwell C58, a machete would be closely controlled to be Rockwell C52, and a power lawnmower blade Rockwell C40) wootz can hold an edge because about half of it is made up of extremely hard iron carbide. An un-hardened wootz blade should be able to hold an edge for cutting through armour and flesh, yet still take quite a beating without breaking in half. I am not a blademaker, just a guy whose job has involved regular steel. Now its time for the wootz guys to chime in. |
25th November 2013, 09:01 AM | #12 | |
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Quote:
spiral |
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25th November 2013, 11:03 AM | #13 |
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Thanks for that . Clear and very helpfull. My naive observations were based on practical experience of traditionally case hardening gun parts not on any real understanding of metallurgy. If I follow the description of wootz manufacture given by one 19 th century observer... That is chop the iron into very small bits and pack it in a crucible with finely chopped wood ; seal it with clay and heat it for some time , I know that what I am going to get is a lot of bits of soft iron with a very hard skin of higher carbon steel on the surface. The longer I keep it heated the thicker this coating will get but it is unlikely to affect the core of each lump which will remain as soft iron. I might reason if I got the temperature as high as I could all the lumps might fuse together but not actually become molten. If I then bashed it around to consolidate it my orriginal little lumps each now coated with a skin of high carbon steel are going to get distorted and broken up and , depending on how I manipulate the lump , could end up appearing as bands or layers of hard steel in a matrix of softer iron. Are things sometimes that simple ?
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25th November 2013, 01:12 PM | #14 | |
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Quote:
Regarding wootz, I believe this article maybe of great value regarding your understanding in how the wave patterns (damask) forms: http://www.tms.org/pubs/journals/JOM...even-9809.html Actually, it was one of the most important references - regarding damask - in my masters dissertation; if not the most important of all. Hope this helps! Best regards, Ahmed Helal Hussein |
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25th November 2013, 01:18 PM | #15 | |
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Quote:
http://materials.iisc.ernet.in/~woot...tage/WOOTZ.htm |
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30th November 2013, 11:16 PM | #16 |
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Thanks to all. I had done a bit of background reading around the subject, but apparently not enough. What set me of was the observation that all researchers and experimenters trying to re create wootz start with molten iron which is carbonized either by adding charcoal or co fusion with cast iron. Which looks sensible since wootz is crucible steel. Until, that is you read Sir Richard Burtons first hand description of the process. (The book of the sword 1886) Which describes iron, which is first, converted into steel by the cementation process and only subsequently melted to form crucible steel. Subtle difference. Was this an important part of the process that nobody seemed to be looking at? I ran this idea past a contemporary maker of wootz and after a lengthy exchange the conclusion was it was a rubbish idea. It wouldn’t make any difference so it’s back to the science. I had no idea that wootz was such a complicated and emotional issue.
However, before leaving the subject does anybody have an opinion on the probable constitution of this barrel? Its currently loosely attached, in the way they usually are, to a Tibetan matchlock but may well be Persian. We know it’s twist welded but how would you describe the banding? Is it patterning welded, wootz or what? Last edited by Raf; 1st December 2013 at 10:19 AM. |
1st December 2013, 03:12 PM | #17 |
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Of course it is pattern welded. Wootz was never used to manufacture barrels.
Get yourself a book by Manfred Sachse "Damascus Steel" http://www.amazon.com/Damascus-Steel...manfred+sachse and it will clarify most, if not all, of your confusions. |
2nd December 2013, 10:37 PM | #18 | |
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Quote:
I second and third Sachse book. As usual I am late to the discussion...the sword blade is etched and done in a way to note try too hard to appear as anything different. I have seen some etch jobs which I had to really look at for a while to pick up up. One modern artist is forging pattern-welded plates and using that to make molds into which he pours bronze. I had to look at his stuff VERY closely as the effect looks great. He does furniture with the technique. Ric |
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