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Georgian 'Bulat' technology by Zaqro Nonikashvili


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#1 Klaas remmen

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Posted 22 November 2010 - 10:53 AM

Seerp Visser and myself have been interested in Wootz and Bulat for quite some time, and during visits to all kinds of knife shows, weapongallery's... we got in contact with Gotscha Lagidse My link).
Gotscha is Georgian but he lives in Rosendaal in the Netherlands (not very far from Antwerp in Belgium).
He studied the Bulat technology with his friend Zaqro in Tsibili, and so we had an overload of questions for him, concerning the history and technology of the Bulat.
After lot's of communication with Gotscha, the idea of getting Zaqro to Belgium and make it in to a Bulat-worshop rose, so last weekend (20-21/11) the workshop was helt.
A total of 20 interested persons took part of the workshop.

Afterwards Zaqro was asked if he was OK with us further exploring and communicating about his technique, since he had been testing all kinds of Bulat making for the last several years (and over 800 smelts) to get where he is today. He shared our opinion that evolution can not come out of keeping secrets and he was fine with us sharing his technique, as long as we told everyone this was the Georgian way.

So here it is, the Georgian way of making Bulat, AKA Wootz, Crucible steel.
Enjoy

Zaqro makes the crucibles himself out of :

(parts are volume-parts)
7 parts Grog(crushed fireproof brick)
3 parts cokes
2 parts kaoline (China clay)
1 part fireproof clay (common white clay)

Every ingrediënt is crushed to dust-sized particles
Water is added so that it sticks togheter when squeezed, but falls apart when you try to break it.

This is compressed tightly in a mould, and afterwards pushed out.

The crucible is filled.
Zaqro prefers pure ferritic Iron, thus we used ARMCO plate, which we cut into small squares (10X10mm). Normal welding electrodes are also good to use.
He takes about 300g of iron to fill his crucible, which he divides in to two equal parts.
One part is put in the crucible at the bottom. on top of this, he puts a layer of sand. this sand comes from a georgian river, but every sand or glass that melts at around 1100°C will do the trick.
On top of this sand he puts a layer of charcoal of about 10mm thick.
That he punt on half of the remaining part of Iron. On top of this, he puts another part of charcoal. on top of this he puts the last part of Iron, and on top of that he puts another part of charcoal.
He also added some manganese to 'calm down' the melt.

Posted Image
This is a copy of a drawing by Seerp, for the charge of the crucible.

The lid of the crucible is made by mixing the leftover Kaoline and clay to form a pancake which is carefully placed on top of the crucible. Zaqro makes a hole of about 8mm in this lid.
The crucible is put into an oven, made on top of the forge by fireproof bricks. the crucible is placed on a piece of brick on the bottem of the oven, and is relativly slow heated with charcoal.
When there is a good fire going on at the bottom of the oven, cokes or antracite is added (not too much) to the oven. when the entire crucible is surrounded by glowing cole, the time is noted and the entire oven is filled with cole.
Posted Image
Photo of oven when the time was noted.

Now the oven is run for about an hour. afther this hour the wind of the forge is shut down, and the crucible is left to cool inside the glowing cole.
Posted Image

It is best to let the oven cool down entirely before removal of the crucible, but at the workshop the crucible was removed after about 1 hour.

the result inside the crucible is remarkable: At the bottom an ingot is found. on top of this ingot there is a layer of glass, from the sand. on top of this glass there is leftover charcoal.
What happened inside the crucible is as follows: The upper part of the charge (on top of the sand that is) has carburised to form cast iron. Meanwhile, the sand has been molten and gotten into the pure iron at the bottom of the crucible. The cast iron with about 3% of carbon in it melts between this pure iron at the bottom, pushing the glass back to the top of the steely mass, preventing any acces carbon to diffuse into the liquid.
So this type of charge gets itself carburized to about 1,5% automaticly. By using other lengths of firing Zaqro said he could influence the carbon content of the ingot.

the as-cast ingot:
Posted Image

When the ingot is cooled, zaqro heats it up to about 1150°C. at this stage, the leftover glass on top of the ingot is acting like 'champagne bubbles', when he listens very carefuly he can hear it making 'the sound of a little snake'. this glowing procedure takes about half an hour.
He leaves the ingot on the anvil to cool it down to an orange heat, and he forges the first time.
At first he strikes the ingot with just a few blows, and never turns the ingot while forging, only to turn it when he makes another heat-cycling.

He never goes under 800, and never over a 1000°C when forging, and uses for about 65 heats to forge a knifeblank.


He did three melts which were all succesful. He forged two of the ingots out, resulting in 3 knives with a very nice pattern, and one piece of Bulat (roughly 60X20X8mm) ready to be forged into a knife.
One knife, complete with making the crucible, melting, forging and hardening but still to be finished by grinding takes him about 7 hours.

more pics will folow!

Edited by Klaas remmen, 22 November 2010 - 10:57 AM.


#2 Greg Thomas Obach

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Posted 22 November 2010 - 12:51 PM

thanks Klaas

and thanks Gotscha for the sharing

the crucible process and arrangement of the charge is very interesting.. it alway amazes me that there are so many techniques to produce crucible steel.
- cool that he uses some manganese... i've noted the glass from that comes out very black/dark (from my experience )
- aswell, its cool that he can do that on his coal forge..... i've had a couple nice disasters do it like that...for me, i ended up with a molten crucible dissolved and goobering up my air grate... :lol:

definitely a good technique if he can easily produce forge out steel..without problems..

the only bulat i have seen on the net was a saber... and it had a very dendritic pattern with a very nice glossy black background... .. not as glossy black a khorasan blade, but still cool to see


no flipping the ingot... hmmm.. i usually do the opposite... and flip often.. as i live in a terribly cold environment... the anvil steels alot of heat from ingot....so i flip often to avoid a cold and cracky bottom..


excellent post...
Greg

#3 Jokke

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Posted 22 November 2010 - 02:13 PM

yes. super!
had to put a link to my german thread to make more people aware!
Thanks a lot for sharing,
and YES: no secrets!
that's what I love
very clear experience
and nice ingots with a clearly defined range of C and weight

Greetz
Jokke

#4 Christopher Price

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Posted 22 November 2010 - 03:07 PM

Looks like a nice approach if you're starting with pure iron. For the ore-melters, one must account for reduction first, though, and I'm not sure how this arrangement would affect that. Maybe a layer of charcoal at the very bottom... and up the charcoal/ore ratio a bit?

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#5 Klaas remmen

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Posted 22 November 2010 - 04:44 PM

Zaqro mentioned the use of direct-reduction of hematite-magnetite ore in the same way in crucibles...
Today I read the article :Rehren, T. and O. Papachristou, Similar like white and black: a comparison of steel-making crucibles from Central Asia and the Indian subcontinent. Man and Minind- Mensch und Bergbau: studies in honour of Gerd Weisgereber on occasion of his 65th birthday, 2003: p. 393-404.
in which there are mentioned the tall crucibles from central Asia. I believe it might be possible that they made these direct reductions, and yes, Jeff, you told me in Londen you do this sometimes. How does it work? And is it based on historical accounts?

#6 Jacques Delfosse

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Posted 22 November 2010 - 05:14 PM

Gotscha and his friend ware also in Gembloux for our 12th. BKS Cutlery Days, on November 13 and 14th.
Gotscha is also making very nice armours..

#7 Jan Ysselstein

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Posted 22 November 2010 - 11:16 PM

[quote name='Klaas remmen' date='22 November 2010 - 09:53 AM' timestamp='1290441207' post='171308']

Klaas,
Thank you and thank you Zaqro for a very well documented description of the method. In many respects it is very similar to what is done here ( excluding the ingredients..I use cast iron and iron) , including warming the crucible with charcoal..I have not tried crushed coke in my clay crucibles but am again experimenting with charred rice hulls...I just had to try soaking them in oil and was a little shocked when the hulls absorbed a lot of oil and the oil soaked hulls mixed into the wet clay without a problem. After firing, ( just long enough to melt gray cast iron ) the ceramic was black (soot) inside and not just at the location of the charred hulls.... charred hulls contain about 40% carbon prior to soaking, so the additional oil must really assist in maintaining a reducing atmosphere in the ceramic..I have to assume this was at least one of the reasons for their use.

What jumped out at me is the weight of the ingot....so small.....is a larger amount ( and crucible) ever used?
Here is a photo of a handmade crucible hanging in a sleeve of coke.....I am not sure if this one led to a successful bar....as there were and (are) many that do not....maybe when I can say I did 800, there will be some predictability to the process. Due to the high fire danger here in summer I have to use gas...but now ( it is raining) I can use up some of the coke .


Jan

#8 Klaas remmen

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Posted 23 November 2010 - 03:50 AM

Jan

The ingot is very small indeed. But you can easely forge two knifes from this. For bigger crucibles and charges Zaqro said he had to use a diffrent type of furnace, as was escavated in Merv or Uzbekistan.
He mentioned that Ann Feurerbach (if I remember correct..) wrote about a filled crucible with ore and charcoal.

This type of crucible charge comes from an old police report, wehn Tsaar Alexei Mihailovich sent four bladesmiths to Georgia to learn the craft. The Georgian family was forced to tell the secret and it was well noted.
So this is a type of crucible charge that was used at the end of the 18th century in Georgia. There is a great deal of very interesting literature about crucible steel in Russian, but it is hard to find, and even harder to read :rolleyes:

#9 Klaas remmen

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Posted 23 November 2010 - 03:51 AM

Jan

The ingot is very small indeed. But you can easely forge two knifes from this. For bigger crucibles and charges Zaqro said he had to use a diffrent type of furnace, as was escavated in Merv or Uzbekistan.
He mentioned that Ann Feurerbach (if I remember correct..) wrote about the findings of a filled crucible with ore and charcoal, that has not been firered.

This type of crucible charge comes from an old police report, wehn Tsaar Alexei Mihailovich sent four bladesmiths to Georgia to learn the craft. The Georgian family was forced to tell the secret and it was well noted.
So this is a type of crucible charge that was used at the end of the 18th century in Georgia. There is a great deal of very interesting literature about crucible steel in Russian, but it is hard to find, and even harder to read :rolleyes:



#10 Cyrus

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Posted 23 November 2010 - 10:32 AM

Hi Klaas,

very interesting, I wish I could come but for me it was not possible. I think you can still melt with this type of furnace 2,5 kg of iron, on the german forum there is a man from Austria and he melts with such a furnace 2 kg and more.

I like the way how Zaqro fills the crucible, I will try that in the next melt. I stll have a homemade crucible sitting in my living room, that will be used. I made it like the ones, that have been found in Uzbekistan.

Whats about a melt with you, Achim, Andreas and myself? Maybe we should organize something!?

Best Regards, Cyrus

#11 Jeff Pringle

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Posted 23 November 2010 - 12:52 PM

Klaas – extend thanks to Zaqro for sharing this interesting method, and please post some photos of the steel!

If you check out Rehren & Papakhristu’s other paper - “Cutting Edge Technology - The Ferghana Process of medieval crucible steel smelting,” they do the math to show the charge could not be ore -
“Comparing the result of this calculation to the
average total volume of the crucibles of just below
1000 cm3, it becomes obvious that the crucible charge
could not possibly have consisted of iron ore,
agglomerate or even pure iron oxide. The volume of
the iron oxide alone is already more than the entire
crucible can hold, and that already assumes an
unrealistic tight packing of the iron oxide without any
spaces or voids. In addition, twice that volume would
have been necessary to hold the charcoal required
to reduce the iron oxide to metal.”
And in “Persian Steel,” Gilmour tracks down the idea that ore was used to one of those unreliable 19th century Europeans, CR von Schwarz, who then gets repeated by others, including Belaiev (1918), which might be where Zaqro got the idea.
I only use ore ‘cause it is important to me that I’m creating my own metal, rather than just re-melting commercial (s)crap to make my steel…I’m not sure anyone else is habitually so foolish, Chris. Except maybe Jan, but you (Jan) are 2-staging it at this point, no?
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#12 Jan Ysselstein

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Posted 23 November 2010 - 01:13 PM

Klaas – extend thanks to Zaqro for sharing this interesting method, and please post some photos of the steel!

If you check out Rehren & Papakhristu’s other paper - “Cutting Edge Technology - The Ferghana Process of medieval crucible steel smelting,” they do the math to show the charge could not be ore -
“Comparing the result of this calculation to the
average total volume of the crucibles of just below
1000 cm3, it becomes obvious that the crucible charge
could not possibly have consisted of iron ore,
agglomerate or even pure iron oxide. The volume of
the iron oxide alone is already more than the entire
crucible can hold, and that already assumes an
unrealistic tight packing of the iron oxide without any
spaces or voids. In addition, twice that volume would
have been necessary to hold the charcoal required
to reduce the iron oxide to metal.”
And in “Persian Steel,” Gilmour tracks down the idea that ore was used to one of those unreliable 19th century Europeans, CR von Schwarz, who then gets repeated by others, including Belaiev (1918), which might be where Zaqro got the idea.
I only use ore ‘cause it is important to me that I’m creating my own metal, rather than just re-melting commercial (s)crap to make my steel…I’m not sure anyone else is habitually so foolish, Chris. Except maybe Jan, but you (Jan) are 2-staging it at this point, no?


Jeff,
Yes I suppose it is two staging...making the metal then processing it into wootz ...

Jokke..Regarding "secrets" I frankly hope people keep their secrects ...iron behaves predictably and so so ceramic materials..both have been studied and documented an almost infinite amount...the real fun about wootz is going there, not being there. Well the "not being there" is a guess because I can only imagine what it is like to be there.

Jan




Jan

Edited by Jan Ysselstein, 23 November 2010 - 01:30 PM.


#13 Cyrus

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Posted 23 November 2010 - 01:53 PM

Jeff,
Yes I suppose it is two staging...making the metal then processing it into wootz ...

Jokke..Regarding "secrets" I frankly hope people keep their secrects ...iron behaves predictably and so so ceramic materials..both have been studied and documented an almost infinite amount...the real fun about wootz is going there, not being there. Well the "not being there" is a guess because I can only imagine what it is like to be there.

Jan




Jan



Jan,

you are absolutely right, the research, reading and melting plus forging is the fun and not really knowing when or if you arrive. If it was as easy as pattern welding it would be boring, in'it?

Cyrus

Edited by Cyrus, 23 November 2010 - 01:57 PM.


#14 Jokke

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Posted 23 November 2010 - 04:15 PM

Jeff,
Yes I suppose it is two staging...making the metal then processing it into wootz ...

Jokke..Regarding "secrets" I frankly hope people keep their secrects ...iron behaves predictably and so so ceramic materials..both have been studied and documented an almost infinite amount...the real fun about wootz is going there, not being there. Well the "not being there" is a guess because I can only imagine what it is like to be there.

Jan

Hi,
So you should have had fun to be along in what we did in July in a place called Kleinenbremen, a small town near Minden, Westfalen:
http://www.messerfor...t=Kleinenbremen
check post #5 for pics, we got 1,7 T of ore out of this old ore mine and had a couple of Renn-fires there
and I made a small cake out of the smelted iron for the guys who did put up the whole thing

about secrets... well for me it is about sharing
and thats what we all do here, don't we?! anyone can keep their secrets, if they want to, you too of course

best wishes

Edited by Jokke, 23 November 2010 - 04:16 PM.

Jokke

#15 Klaas remmen

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Posted 23 November 2010 - 05:07 PM

well there is a diffrence in keeping secrets and 'know-how'.
Do you remember the first time you forged? did that work out the way you wanted?
I myself once forged 2600 nails for a job, only afterwards I had te feeling I could really forge a nail. Same with crucible steel.
I believe it is not possible to make a 'how to' guide to the perfect watered crucible steel.
It is all about technique and skill, and you need to practice a whole lot to get there.

That is the reason why I can only recommend to take part in a workshop like this one. It is not what I or someone else writes down here, it's the exact glowtemperature, the small remarks,... that are as important as the rest.
With someone like Zaqro to teach you you immediatly take a huge step forward.

What I am trying to say is that posting zaqro's information sets up a conversation from people around the world, and we can all learn from that... But it is sure as hell not going to make you all able to make perfect shamshir's :P


On topic: Today I forged out a melt I did at the workshop. it didn't crumble (hooray!) but the pattern isn't that fantastic. it's constructed out of very small groups of carbides . I just spoke to Zaqro for the last time before he went back to Georgia, he told me this was due to a to high glowing procedure.

here is a picture of the little knife that I forged out of it.
Posted Image

As you can see there is not really a big pattern...
Posted Image

this is the pattern of the knife.
Posted Image

this is the pattern with same magnification of the blank that I did not forge into shape yet
Posted Image

this is the pattern of Master Zaqro...
Posted Image

#16 Christopher Price

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Posted 23 November 2010 - 08:51 PM

I only use ore 'cause it is important to me that I'm creating my own metal, rather than just re-melting commercial (s)crap to make my steel…I'm not sure anyone else is habitually so foolish, Chris. Except maybe Jan, but you (Jan) are 2-staging it at this point, no?



Well, that's what happens when I "monkey-see, monkey-do", I guess. I'm over my brain fart now, I hope.
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#17 Richard Furrer

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Posted 24 November 2010 - 09:19 AM

I only use ore ‘cause it is important to me that I’m creating my own metal, rather than just re-melting commercial (s)crap to make my steel…I’m not sure anyone else is habitually so foolish, Chris. Except maybe Jan, but you (Jan) are 2-staging it at this point, no?


Using ore
Lets not forget the burping and spillage of the dross and the havoc it has on the furnace and fire. It will eat many lids (inswool and satanite will last about 20 minutes) so a sealed crucible rarely remains sealed.
An A6 crucible filled with iron ore concentrate and a bit of glass will make a small handful of iron by the time it reduces down.
It would be simpler to use bloom material than direct crucible reduction.

Ric
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#18 Jeff Pringle

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Posted 24 November 2010 - 12:11 PM

:D :D
What could be simpler than ore in, ingot out?
you just need to use a bigger crucible...
;) B)
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#19 Richard Furrer

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Posted 24 November 2010 - 12:28 PM

:D :D
What could be simpler than ore in, ingot out?
you just need to use a bigger crucible...
;) B)

The charcoal always floats out with the dross or sits like a balloon on the liquid metal....
Best I have found is to run a bloomery smelt, sort the material, pack carburize and then melt..or melt in the pack carburizer and then use that as the cast iron additive to the bloom which did not become anything but reduced iron.

A bigger crucible eh.....I have a number 80 around here somewhere.....Not sure I want a 200 pound wootz ingot though.......the preheat to forge would be...time consuming. ^_^

Ric
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#20 Klaas remmen

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Posted 25 November 2010 - 04:25 AM

Here is a picture of a bulat knife by Zaqro:
Posted Image

Edited by Klaas remmen, 25 November 2010 - 04:27 AM.





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