• Announcements

    • Alan Longmire

      IMPORTANT Registration rules   02/12/2017

      Use your real name or you will NOT get in.  No aliases or nicknames, no numerals in your name. Do not use the words knives, blades, swords, forge, smith (unless that is your name of course) etc. We are all bladesmiths and knifemakers here.  If you feel you need an exception or are having difficulty registering, send a personal email to the forum registrar here.  
Klaas remmen

Georgian 'Bulat' technology by Zaqro Nonikashvili

268 posts in this topic

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.

 

Vullingkroes.jpg

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.

oventijdenssmelten.jpg

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.

Kroesnasmelteninoven.jpg

 

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:

gesmoltenbulat.jpg

 

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

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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?

 

Jeff to the white courtesy phone, please...

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

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..

Share this post


Link to post
Share on other sites

 

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

Share this post


Link to post
Share on other sites

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:

Share this post


Link to post
Share on other sites

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:

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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.messerforum.net/showthread.php?t=79301&highlight=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

Share this post


Link to post
Share on other sites

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.

IMG_8779.jpg

 

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

IMG_8775.jpg

 

this is the pattern of the knife.

frame2.jpg

 

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

frame1.jpg

 

this is the pattern of Master Zaqro...

frame0.jpg

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

 

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

Share this post


Link to post
Share on other sites

: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

Share this post


Link to post
Share on other sites

Here is a picture of a bulat knife by Zaqro:

12R-71_Blackbird.jpg

Edited by Klaas remmen

Share this post


Link to post
Share on other sites

Hi Klaas

 

beautiful knife !!! as they say... the proof is in the pudding ! his techniques do produce a very nice pattern

 

 

 

Ric ... A number 80 :o :o are you thinking of replicating the iron pillar of Delhi :lol: could be a big tourist draw to area

 

 

Greg

 

ps.. i also like to use wrought and C.. ..theres lots of wagonwheels and chain out there and the nice part is it has its own glass in the iron... makes a nice thin black glass on the top of the ingot

 

what bout using a producer gas and reducing an ore biscuit ...then add

Share this post


Link to post
Share on other sites

Just read another interesting thing in Mushet, D., Experiments on wootz. Philosophical magazine, 1805. 95: p. 40-48.

Seems to me that on page 46 he describes a method simmelar to the Georgian method. With pieces of Iron that become Liquid and run down to the bottom of the crucible where ironore is located, and in this way reducing the cast iron to steel. Or at least that is what I understand..

read at: My link

Share this post


Link to post
Share on other sites

Hi Klaas

 

beautiful knife !!! as they say... the proof is in the pudding ! his techniques do produce a very nice pattern

 

 

 

Ric ... A number 80 :o :o are you thinking of replicating the iron pillar of Delhi :lol: could be a big tourist draw to area

 

 

Greg

 

ps.. i also like to use wrought and C.. ..theres lots of wagonwheels and chain out there and the nice part is it has its own glass in the iron... makes a nice thin black glass on the top of the ingot

 

what bout using a producer gas and reducing an ore biscuit ...then add

 

Pillar:

Actually Greg, about a year before his death Bala was in my shop and we were talking about that very thing http://www.iitk.ac.in/mme/obituary/. It would have occurred in India though. Since his death I have considered the forging of such a thing here with a dedication to him.

 

The glass color always semmed to come out various shades of green for me if I used sand or clear or green at the start. I have not used brown glass. When I use Borax it always comes out the bottom of the crucible. :(

 

Ric

Share this post


Link to post
Share on other sites

With pieces of Iron that become Liquid and run down to the bottom of the crucible where ironore is located, and in this way reducing the cast iron to steel.

 

This is how I do the process...but with cast iron on top of the "pure" iron...in this way the high carbon liquid material is in the most contact with the lowest carbon material....I have stopped the process at various times to see what is happening and it is best to think of the cast iron as dripping and melting and the liquid trickles down and solidifies as it gives up carbon...like a melting and re-freezing icicle. As the iron gains carbon it too melts and drips...over time what is left are a few thicker bits of iron bathing in a liquid pool of higher carbon steel..till they too gain carbon and melt away.

The above is the real reason for having small strips of iron as feed stock....best to have as large a surface area to mass as possible. It takes less fuel to forge the bits small than to run the furnace at high heat hoping to melt the thick bits of iron.

Think of this next time you put ice in your coffee too cool it down.

 

Ric

Share this post


Link to post
Share on other sites

Excellent points, Ric. Thank you for sharing.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now