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Georgian 'Bulat' technology by Zaqro Nonikashvili


Klaas remmen
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Hi,

I once read that you can melting a wootz ingot two times.

The finished ingot, cut about 10 percent of the top and re-melting.

Such treatment is to give a better clean.

 

Nice experiment Jan.

 

---

Adam

 

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

 

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,

Don't be so hard on poor Cecil, we may see an article one of these days titled " The Exoneration of Cecil von Schwartz". There are times when I think it was possible ( would be possible ), when crucible size and ingot size are opposite extremes ( large crucible. small ingot). It is on my list of things to do this year.

 

Jan

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Hi,

I once read that you can melting a wootz ingot two times.

The finished ingot, cut about 10 percent of the top and re-melting.

Such treatment is to give a better clean.

 

Nice experiment Jan.

 

---

Adam

 

Thanks Adam and Greg,

The crucible is cooling and "it is what it is" . Grabbing a crucible with luted on lid and shaking it is not what I want to do...scary....I think it was liquid but I am not 100% sure...that is harder than sticking a rod in the crucible. I ran just short of 2 hrs and stopped because my crucible seemed to be sinking or shrinking..when I pulled it out it was OK. I will go have a look late tonight.

Oops....the crucible was not glazed.

Jan

Edited by Jan Ysselstein
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Thanks Adam and Greg,

The crucible is cooling and "it is what it is" . Grabbing a crucible with luted on lid and shaking it is not what I want to do...scary....I think it was liquid but I am not 100% sure...that is harder than sticking a rod in the crucible. I ran just short of 2 hrs and stopped because my crucible seemed to be sinking or shrinking..when I pulled it out it was OK. I will go have a look late tonight.

Oops....the crucible was not glazed.

Jan

 

 

Here are a couple of pics of the little "egg" . The glaze would have helped some ..there was no excess carbon visible when the crucible was opened. The "raw" bloomery iron was a problem (slag ate some holes in the crucible), I will not do that again (refine it at least 2x first). Now I will cut it open and see if the carbon is in the air or the metal...the surface of the ingot gives a very nice high carbon spark ( I know it is not cast iron ). I will sort out how to progress and should have a better sample soon.

 

 

 

 

Jan

Edited by Jan Ysselstein
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Hi Jan

 

it is fully melted... no bars can be seen poking outward .. so that is good news !

 

I'm interested to see it when you cut it... is the gas pockets a just a surface problem?... to be honest, it may have been just a matter of more time in the furnace for it to settle down..

 

any gas pockets show some dendrites.?

 

it must have eaten up all the carbon...which is good, unless its trapped inside...

 

Greg

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Hi Jan

 

it is fully melted... no bars can be seen poking outward .. so that is good news !

 

I'm interested to see it when you cut it... is the gas pockets a just a surface problem?... to be honest, it may have been just a matter of more time in the furnace for it to settle down..

 

any gas pockets show some dendrites.?

 

it must have eaten up all the carbon...which is good, unless its trapped inside...

 

Greg

 

Greg,

This not a bad situation...better I get a good grip on the process than having it too easy in the beginning ...it should be fun trouble shooting...I just do not believe the iron contained that much slag-so I am doomed to repeat the test and maybe create another cute remelt. I will be hanging out in India for a while before heading to other places. One begins to understand why 800 melts..not only do we want a good melt but we want to know why it is good (or in this case bad).

 

Jan

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Hi Jan

 

it is fully melted... no bars can be seen poking outward .. so that is good news !

 

I'm interested to see it when you cut it... is the gas pockets a just a surface problem?... to be honest, it may have been just a matter of more time in the furnace for it to settle down..

 

any gas pockets show some dendrites.?

 

it must have eaten up all the carbon...which is good, unless its trapped inside...

 

Greg

 

Greg,

 

Full of holes tunneling into each other I have created steel foam some very fine stress cracks throughout and in the crucible..I have to drop this for a few weeks..winter (rain) is finally coming to western USA and I have to get ready to make some ingredients including enough low ash charcoal to allow me to repeat this test in a lower O2, CO2 atmosphere, so while you are forging all that wootz, I am digging a hole for myself. The old charcoal fines are now in the garden making life a little better for the worms.

 

Jan

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biochar is becoming a big thing... somehow the old Maya gardeners knew something that all our science is finally stumbling on

 

if the ingot is very swiss cheese like... then i'd guess that a chemical reaction was going on and it wasn't at an equilibrium of sorts... it might be a good candidate for a remelt as it is

 

occasionally i get a porous ingot but not often a swiss one.. when it does happen i mostly get several big annoying bubbles withing the charge.. (enough to ruin my day and chop shop the ingot)

 

If memory serves me right ...i did have this happen and i cut the ingot in two... put one in a crucible with some added borax with glass.... the other without the borax

- the borax one came out without bubbles and the other one was just about as bad as it was previously ... so in that case it did something but that is by far the only time that happened for me... i'm usually unlucky with this kind of experiment

 

no more wootz forging for awhile.. have two curved prospects on the go ...

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biochar is becoming a big thing... somehow the old Maya gardeners knew something that all our science is finally stumbling on

 

if the ingot is very swiss cheese like... then i'd guess that a chemical reaction was going on and it wasn't at an equilibrium of sorts... it might be a good candidate for a remelt as it is

 

occasionally i get a porous ingot but not often a swiss one.. when it does happen i mostly get several big annoying bubbles withing the charge.. (enough to ruin my day and chop shop the ingot)

 

If memory serves me right ...i did have this happen and i cut the ingot in two... put one in a crucible with some added borax with glass.... the other without the borax

- the borax one came out without bubbles and the other one was just about as bad as it was previously ... so in that case it did something but that is by far the only time that happened for me... i'm usually unlucky with this kind of experiment

 

no more wootz forging for awhile.. have two curved prospects on the go ...

 

Greg,

It all makes sense but unfortunately in this game we all have to make all the moves ourselves, probably because each setup is unique. I am planning a remelt ( I will add a few grams of cast) but what is the point if the crucibles fail....right now I am testing for the porosity of the fired crucibles and I am at 10% +/-3% of the volume of the fired crucible is space ( actual porosity may be greater as I am not measuring closed pores , inaccessible to my food colored water, these closed pores may warp or pop at high temps and open later) . I will be trying again at reducing that ..it is a catch 22 for me and I cannot wait for the new charcoal.

 

I am assigning the major cause of failure to the crucible, then the iron/glass and then the too short a melt time.

 

Jan

Edited by Jan Ysselstein
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Here are a couple of pics of the little "egg" . The glaze would have helped some ..there was no excess carbon visible when the crucible was opened. The "raw" bloomery iron was a problem (slag ate some holes in the crucible), I will not do that again (refine it at least 2x first). Now I will cut it open and see if the carbon is in the air or the metal...the surface of the ingot gives a very nice high carbon spark ( I know it is not cast iron ). I will sort out how to progress and should have a better sample soon.

 

 

 

 

Jan

 

So, the experiment was repeated this evening and the "ingot?" is cooling this moment. Below is a photo of the porous ingot made with a very porous crucible.

 

Jan

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reminds me very much of my last melts, Jan

Hope you get the crucibles the way you want them.

I do admire the energy you put into your research,

for myself, I allow me to use the "shortstep" of modern clay-c or si materials -

funny enough to end up with the same problems

(from the looks of it)

 

best regards

Jokke

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Actually, its bad..... BUT, on the otherhand with your conclusion that it is the result of a porous crucible... it is a great example for us to diagnose future problems

 

- Crucible porosity

 

and even the manufactured crucibles are subject to this aswell ... and those are supposed to be pressed together to ensure a solid product..

 

i've noticed that my crucibles that have a nice continuous ceramic mottling on the outside will usually produce decent ingots.. but using a new crucible will most likely up the chances of getting a dud

 

thats why i alway fire the new crucible at the first melt of the day... the furnace is usually running abit cold compared to later on... so if i'm gonna have a dud, i'd rather it be the first one ... for me the best ingots are usually the 3rd and 4th melt, the furnace wall are loaded with heat energy.... hot stuff, but thats the name of the game

 

you can coat your crucible with some 36 cement... that works.. sometimes is slurps off ...depends how hot your runnin that day..

 

 

thank you Jan for the picture.. it tells alot

 

Greg

 

ps.. i do see dendrite in the bubbles..

 

pss.. would adding extra grog to the outside of the crucible help

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Actually, its bad..... BUT, on the otherhand with your conclusion that it is the result of a porous crucible... it is a great example for us to diagnose future problems

 

- Crucible porosity

 

and even the manufactured crucibles are subject to this aswell ... and those are supposed to be pressed together to ensure a solid product..

i've noticed that my crucibles that have a nice continuous ceramic mottling on the outside will usually produce decent ingots.. but using a new crucible will most likely up the chances of getting a dud

thats why i alway fire the new crucible at the first melt of the day... the furnace is usually running abit cold compared to later on... so if i'm gonna have a dud, i'd rather it be the first one ... for me the best ingots are usually the 3rd and 4th melt, the furnace wall are loaded with heat energy.... hot stuff, but thats the name of the game

you can coat your crucible with some 36 cement... that works.. sometimes is slurps off ...depends how hot your runnin that day..

thank you Jan for the picture.. it tells alot

Greg

ps.. i do see dendrite in the bubbles..

pss.. would adding extra grog to the outside of the crucible help

 

 

 

Below is a photo of the rerun of raw bloomery iron carburized to a little 717 gram wootz cake. The crucible was still porous but did not fail by indicating gross porosity ( leaking fluid out to the exterior) . This is the beginning of some exiting experimentation in getting the carbon chemistry right...this cake sparks as very high carbon steel at the surface,

 

 

Greg,

Yes there were some dendrites at some of the bubble surfaces ...the porosity issue has me so frustrated I am designing a furnace using charcoal as I will probably just have to learn to live with it. I also need to learn how to lute more effectively as my XS carbon was again gone.

 

Jan

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Jan.

 

I have had all most similar 4 kg ingot. Used new factory Alo2 crucibel so that crucibel reaction would

have not bean that strong as it was SiO2 crucibel..well crucibel was realy not that good at all..ingot looked like cheese

but top was ok ´is...did not cut it half but forge it to bar..and it was ok...so all that was just out side.

 

However...next melt was totally disaster crucibel was eaten by slag and slumbed and liquid steel was at bottom of furnace..

So they were bad crucibles..

 

Another observation was gas air mix...if it was lean...it did turn crucibles frogspawn glased pottery...and erosion was sevire..

This erode Sio2 like never before...lean and oxygen...bad not so gas thight crucible--> there could be some.

 

But I think you are right about your crucibles..it could be porous...or do you think there could be other source of oxygen??

 

I realy like the shape and size of those, realy hope that you will crack the porous issue.

 

Good luck.

 

Niko

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Jan.

 

I have had all most similar 4 kg ingot. Used new factory Alo2 crucibel so that crucibel reaction would

have not bean that strong as it was SiO2 crucibel..well crucibel was realy not that good at all..ingot looked like cheese

but top was ok ´is...did not cut it half but forge it to bar..and it was ok...so all that was just out side.

However...next melt was totally disaster crucibel was eaten by slag and slumbed and liquid steel was at bottom of furnace..

So they were bad crucibles..

Another observation was gas air mix...if it was lean...it did turn crucibles frogspawn glased pottery...and erosion was sevire..

This erode Sio2 like never before...lean and oxygen...bad not so gas thight crucible--> there could be some.

But I think you are right about your crucibles..it could be porous...or do you think there could be other source of oxygen??

I realy like the shape and size of those, realy hope that you will crack the porous issue.

Good luck.

Niko

 

 

Thanks Niko,

I think I am going to need it, I have a small window of time to get this done (Persian Steel) and move onto welding some of the high carbon material I am storing. The area below 1% carbon on the iron carbon phase diagram I know very little about and I want to have a look at it.

 

Jan

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a little 717 gram wootz cake. The crucible was still porous but did not fail by indicating gross porosity ( leaking fluid out to the exterior) . This is the beginning of some exiting experimentation in getting the carbon chemistry right...this cake sparks as very high carbon steel at the surface,

 

 

The prediction that carbon control will be more difficult using the Indian Process not the Georgian has already been experienced. The 717 gram cake has a tough --s little brother,which I could not cut with my zip blade (2 zip blades , no se puede )...

The latest cake is about the same weight but the structure is cast iron.

 

The photo below shows the 717 gram ingot (see photo above) coated and ready for a carbon diffusion heat treatment (on the right). On the left side of the photo is the latest little cast iron cake which will not be forged.

 

Jan

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Hi Jan

 

that cake on the left looks quite nice.. it doesn't appear to have any bubbling ..

 

if its too high in carb... it could be a candidate for a remelt...just add abit of wrought iron in it to cut down the C

-i really like the shape of the ingots.. very nice size

 

alway great to read your posts

 

thanks

Greg

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Hi Jan

 

that cake on the left looks quite nice.. it doesn't appear to have any bubbling ..

 

if its too high in carb... it could be a candidate for a remelt...just add abit of wrought iron in it to cut down the C

-i really like the shape of the ingots.. very nice size

 

alway great to read your posts

 

thanks

Greg

 

Thanks Greg, I really want to push this through to a place where I am happy with what I have learned. I am planning a remelt and will probably give it another 2 zip blades to see the pattern internally. I started with a set of 6 crucibles..have used 3 my 7 bls of bloom (high P) is rapidly dwindling down to zero. To hold on to as much homemade iron as possible, I am going to use some wrought iron stock, treat it the same way and hope for the best. Almost all wrought iron will have around .1% P at least.

 

By the way 700 gm is not that small but these things are a bear to hold when grinding ...I see a couple oh nicks in the vise.

Jan

Edited by Jan Ysselstein
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Hi Jan

 

i've got the sense that your really tracking this down..!

 

when i use to cut them with the chop saw...i'd get one, once n awhile to fly across the shop.. the zip disc is by far the safer way.. ..could weld a stub tang to the top and lock that in the vise..

- both my bandsaws are just useless to cut them in half... it just polishes the side

 

it would be nice to have a friend with a water jet

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Hi Jan

 

i've got the sense that your really tracking this down..!

 

 

Greg,

I am trying to track down subtle differences in the appearance of different wootz blades and what may be the cause for these. It will be an ongoing project but I am giving it some time this month and next before it goes on the back burner again. Last night I added two more usable ingots to the mix ( having an already hot furnace really speeds things up) and this week-end I hope to get to carbon diffusion, rim softening and some forging. Pretty soon we may put a little egg on E-bay more as an educational effort not so much as a fund raiser ( maybe we can help folks differentiate between mill balls and not mill balls).

 

I will be refining my own steel to eliminate slag from here on , I still get some deep pits on the sides of the ingots using raw bloomery iron. Some of these deep pits form narrow deep tubes into the metal ( like a worm in a fruit).

 

Jan

 

Edit, Jan 19th

There are 4 ingots which should forge well...1 foamy cake and one cast iron remelt. One cake has a large shrinkage basin and will be used as Namban in a later experiment.

I will finish the process on another thread...my thanks to Zaqro and Klaas for starting this thread..trying their methods gave me the confidence to try the Indian method of Wootz making.

 

 

Edit, Jan 24,

Two more not to get forged ingots (both high in carbon, otherwise good) are added to he mix....I am finding I am at the beginning of a new learning curve, hope it levels off soon.

 

 

 

 

 

Jan

Edited by Jan Ysselstein
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  • 3 weeks later...

a little 717 gram wootz cake. The crucible was still porous but did not fail by indicating gross porosity ( leaking fluid out to the exterior) . This is the beginning of some exiting experimentation in getting the carbon chemistry right...this cake sparks as very high carbon steel at the surface,

 

 

The prediction that carbon control will be more difficult using the Indian Process not the Georgian has already been experienced. The 717 gram cake has a tough --s little brother,which I could not cut with my zip blade (2 zip blades , no se puede )...

The latest cake is about the same weight but the structure is cast iron.

 

The photo below shows the 717 gram ingot (see photo above) coated and ready for a carbon diffusion heat treatment (on the right). On the left side of the photo is the latest little cast iron cake which will not be forged.

 

Jan

 

 

Two of the ingots are now bars at about7-8mm thick..each will be ground to remove pits, laps,cracks and other potential hazards. Both bars look promising, though the patterns are relatively fine. Clean the bars, forge the bars and pay attention to cleanliness at the hammer... and etch .

At this point I think I have eliminated some of the problems encountered during the processing of the cast ingot. Some remaining obstacles are, forging to develop an interesting pattern, heat treating andthermal processing to get the best combination of good looks and strength.

I will post some pictures when I am done.

 

Four ingots remain to be forged (though none are expected to be successful) just to gather information on why/how things fail. After forging these two bars I will try to work on getting bigger blooms ( as blooms are now my ingredient) ..when I read about the Indian iron makers the bloom sizes are always way larger than what I get ( for a furnace very similar in size) so you might say I have "bloom envy".....it should be fun. I have actually done my first experiment and ran out of charcoal instead of ore ( that was a first).

Jan

 

PS...I have lost the link I had to a Russian website showing a lot of beautiful wootz blade samples photographed in small paper frames...if anyone has that link would you send or post it...thank you.

Jan

Edited by Jan Ysselstein
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Jan, do you mean this thread in talk.guns.ru: http://talks.guns.ru/forummessage/79/763891.html'

[

 

Janne,

Yes that is the link...thank you very much......I hope to add to that soon but I do not know if my lettering skills are good enough.

 

The two bars were forged at a relatively low temperature to break up any large particles. One bar was found to be severely loaded with cracks ( this was the bar with the large shrinkage basin ).......the other bar looks ok. The cracked bar was cut into 3 coupons for spheroidizing trials.

Coupon 1 failed and cracked during an oil quench...the lesson learned here ( I hope) is ..remove all the decarb before quenching , stress relieve before quenching and shape to a symmetric smooth shape...do not soak too long if the sample is thin (keep an eye on the decarburization process) . I hope to approach spheroidization in two differnt routes D.E.T. and subcritical cycling and slow cooling.

 

Jan

Edited by Jan Ysselstein
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Janne,

Yes that is the link...thank you very much......I hope to add to that soon but I do not know if my lettering skills are good enough.

 

The two bars were forged at a relatively low temperature to break up any large particles. One bar was found to be severely loaded with cracks ( this was the bar with the large shrinkage basin ).......the other bar looks ok. The cracked bar was cut into 3 coupons for spheroidizing trials.

Coupon 1 failed and cracked during an oil quench...the lesson learned here ( I hope) is ..remove all the decarb before quenching , stress relieve before quenching and shape to a symmetric smooth shape...do not soak too long if the sample is thin (keep an eye on the decarburization process) . I hope to approach spheroidization in two differnt routes D.E.T. and subcritical cycling and slow cooling.

 

Jan

 

Coupon #2 ( center of the cracked bar ) has survived the oil quench and is done with one cycle of heat treating...there is no pattern yet ( as Verhoeven and Perttula predict) . I have no equipment to do the heat treating with so there is a lot of guessing. My sample is so heavily scaled, and is now so thin I will have to wrap it in HT foil as I am already less than 3mm. I hope to do another cycle tonight and get a sense of the pattern after 3 cycles. I will edit this post to add some pics.

Jan

 

Edited 2/10/ The second coupon got its second cycle by leaving it in the hot forge at temperature for a "slow" cool...the heat treating foil was too old and stiff so I clayed the blade and added a little carbon to the clay.......it worked surprisingly well.

There are clouds of cementite in the steel but to call it a pattern would be reaching.

Jan

Edited by Jan Ysselstein
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