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New furnace: Bigger bloom.


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...Do you still have the text that i send you some time ago?

 

I like this topic a lot...but why anyone has mention titanium / titanium oxide. Acording whit text TiO2 (satetsu sand Masa whits contais 1-2% of TiO2)...will carburised better and any slag that will procuses is more liquid and runs easyer out fron slag hole...so it not decarb the bloom...

 

I have that article and remember that part. Titanium will also refine the carbides present and help pin them in smaller form, if it remains in the material. Some times titanium will be added to help scavenge oxygen and unwanted minor alloying elements from a melt to help control the final process. Titanium is a good thing. Some old Japanese blades had measurable Ti in the assay. Probably acquired from the native sand now no longer available.

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I see Jeff. I have the book from the Wakou Museum. The walls in the picture represent a solid encasement. The traditional tatara is made of bricks and clay. I keep considering the different furnaces that can be build looking for the best results with the most simplicity and easier-to-operate design. All contributions are appreciated.

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Niko,

Mike,

Thanks for that note on the Titanium Oxide. Titanium seems to have a greater affinity for Oxygen than Iron does and the Titanium Mike mentions,may be in the form of an oxide and may also be what is seen as bright material in the welded zones of some Japnese blades (see Cyril Stanley Smith's "A HISTORY OF METALLOGRAPHY" page 44 ).

 

The author (Yoko Yamabe-Mitarai) of this plan and process for a small Tatara furnace ( I use this as a hand out at smelts, most of which are gatherings around a theme ,food and drink) has some warning about Titanium at higher concentrations.

 

http://inaba.nims.go.jp/movie/tatara/English.html

 

 

Jan

Edited by Jan Ysselstein
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I made the mistake of neglecting this forum for the past week or so -- Thanksgiving, family in town, etc. -- so I thought I'd jump in with a couple of comments.

 

First, though, I did a smelt this week with pretty good results. Jesus wasn't involved in this one but I was following up on results from the recent smelt at his place that started this thread. I put in 36 lbs of ore (a hematite powder) and yielded 10.5 lbs of bloom for a yield of about 30 percent. See photos. I could have kept running it longer and gotten a larger bloom but felt like I was neglecting all my Thanksgiving guests. Spark tests show the bloom to be composed mostly of very high carbon steel. I've attached a photo of my smelter, too.

 

bloom.jpg

 

smelter.jpg

 

Anyway, on to my comments:

 

1. I missed the dust-up (if that's what it was) between Lee and Mike. Lee, if you haven't already bailed on this thread, I hope you'll continue to feel encouraged to jump in here. You may meet some skepticism about your approach here, but to my mind the more we share our thinking on these matters, the better off we all are. I don't want to speak for Mike, but I feel highly confident that Mike's posts were made in a spirit of trying to get to the truth, and not with the intention of being dismissive of your contribution to the thread.

 

2. I thought it might be worth making a few notes about Jesus's and my working relationship. (I'm not sure why I think this would be of interest, but I'm tossing it in anyway.) You might get the impression from reading this thread that Jesus and I have a sort of monolithic combine in which all our smelts are part of a strictly coordinated and rational process. In fact, Jesus and I do smelts together...but we also do our own smelts. We each have our little pet theories and approaches. Our "method" (such as it is) when we do smelts together is to email back and forth a few times, then get together at one of our houses and fire up the smelter. We usually have a little bull session before each smelt to see what seems worth trying, then we dive in. But whoever's house we go to, the visitor defers on final judgements about what the overall approach will be. Jesus tends to be more adventurous than I am. I generally prefer nudging one variable at a time. I've stuck with pretty much the same furnace design since I started doing this a couple of years ago. My original smelter was smaller than my current one, but the construction methodology was almost exactly the same. I use walls made from silica sand and just enough portland to keep the thing from collapsing. Jesus, on the other hand, has contributed several different smelter designs. Aside from the fact that Jesus and I enjoy each other's company (which, in and of itself pretty much justifies catching our clothes on fire once every couple of months), I think our slightly differing approaches to smelting have been really productive.

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Nice looking steel, Walter.

 

As soon as Christmas is past, and I have a little play money, I'm building mine. I have some of the Wisconsin ore from Harley's, and some of Alan's rocks from Cranberry. I'll probably combine some of both in my run. I even have an iron-bearing rock from the Oregon Coast I want to throw in there, though that thing alone probably will have enough flux for the whole shebang. And yes, I'll roast/crush the rocks first... but I kinda like the idea of a 'coast to coast' steel, pure Americana.

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... I don't want to speak for Mike, but I feel highly confident that Mike's posts were made in a spirit of trying to get to the truth, and not with the intention of being dismissive of your contribution to the thread.

 

... Our "method" (such as it is) when we do smelts together is to email back and forth a few times, then get together at one of our houses and fire up the smelter. We usually have a little bull session before each smelt to see what seems worth trying, then we dive in. But whoever's house we go to, the visitor defers on final judgements about what the overall approach will be. Jesus tends to be more adventurous than I am. I generally prefer nudging one variable at a time. I've stuck with pretty much the same furnace design since I started doing this a couple of years ago. My original smelter was smaller than my current one, but the construction methodology was almost exactly the same. I use walls made from silica sand and just enough portland to keep the thing from collapsing. Jesus, on the other hand, has contributed several different smelter designs. Aside from the fact that Jesus and I enjoy each other's company (which, in and of itself pretty much justifies catching our clothes on fire once every couple of months), I think our slightly differing approaches to smelting have been really productive.

 

Since Walter and I have never personally met or communicated before, I appreciate a different view of what I regard as an accurate statement of my intentions to pretty much everything knife related.

 

Surprisingly, the working relationship between Jesus and Walter nearly matches that of John Adams and myself. I suspect it is similar for Lee and Skip. I wonder if having a smelting buddy of some sort pushes the progress made?

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Smelting buddies are essential, they keep you from sticking your head in the fire too often

:blink: or too often they keep you from sticking your head in the fire (where it might do ya some good)

 

Equally important are forums like this one and discussion groups. The EarlyIron group is open to anyone anytime, just drop me ferrognome@yahoo.com a note and you're in. We tried opening the group to the public and that would've worked except that the cybermail at Yahoo.com insisted on advertising EarlyIron to every yahoo subscriber that used the word Iron in their email. We were getting maybe 20 new members everyday.... none of them smelters. So that's how it ended up the way it is.

 

 

There are maybe 40 individuals/teams that I know of who are smelting either Magnetite, Taconite pellets or Hematite Grit. It would be a benefit to everyone to collect smelt reports, furnace designs, successes and failures, etc. in one place so that newbies can get a leg up and not have to start at the beginning like we all did. Nothing fancy is required for a report, just a few sketches and notes about what you were thinking thrown into a word document will suffice.

 

Following on what Mike and Jan have said, I think it would be useful to have a 'standard' tatara furnace design, not that everyone would use that design but it would give each of us something to compare to when we are explaining how our designs are different and why.

 

Best

 

Skip Williams

 

 

Thijs van de Manakker and buddies Smelting at Eindhoven NL, Fall 2006

One mention of Magnetite Sand to these guys and they'll ask you to carry the anvil stone out into the bog for them!

 

Iron%20Makers%20500.jpg

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  • 2 weeks later...

 

One mention of Magnetite Sand to these guys and they'll ask you to carry the anvil stone out into the bog for them!

 

Skip,

I would love to try some bog ore for an unrelated experiment (the Trondelag Horseshoe Furnace) and would be glad to swap with you canceling out the mailing costs. Where is the California bog?

 

Jesus,

 

Though the rains have come, so have a lot of chores which will take priority over smelting. I will probably do a smelt in early January of 2008. I am attaching some photographs of bits and pieces of some of my past smelts, they are selected from the photos I do have, to give an overview of the process. The pictures are not intended to be a "how to smelt iron" but to show an alternative simpler furnace which gives pretty decent results.

 

Jan

 

PS As one photo will show, I love slag

 

http://forums.dfoggknives.com/style_images.../attach_add.png

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http://forums.dfoggknives.com/style_images.../attach_add.png

 

I hope this worked as in previewing the post I only see file names no photos.

Jan

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You definitely achieved a liquidus for some of the bloom. I like the colors and the fractured surfaces. That is also a very interesting variation on a furnance. I'm particularly attracted to the little thigns that make operating it a lot smoother than groveling around on the ground getting dirty. Good job.

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You definitely achieved a liquidus for some of the bloom. I like the colors and the fractured surfaces. That is also a very interesting variation on a furnance. I'm particularly attracted to the little thigns that make operating it a lot smoother than groveling around on the ground getting dirty. Good job.

 

Mike,

 

Thanks, yes I do think the droplets are gathering down under. I have a pile of these chunks around but they are all like eggs. If the white were low carbon steel and the yolk high carbon, these blooms would be like large eggs. I have beaten on these things to a point of "danger" ( I was able the beat some cast iron out of the center of one). So the next run or two should provide a beautiful fracturing bloom, partly due to the dialoge in this thread.

 

By the way for those not forging blooms, even a very dense bloom like the one shown will lose about 60-75% of it's volume due to loss of voids and slag.

This photo is a more realistic CO flame size (the other photo was "show time").

 

Jan

Edited by Jan Ysselstein
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Mike,

 

Thanks, yes I do think the droplets are gathering down under. I have a pile of these chunks around but they are all like eggs. If the white were low carbon steel and the yolk high carbon, these blooms would be like large eggs. I have beaten on these things to a point of "danger" ( I was able the beat some cast iron out of the center of one). So the next run or two should provide a beautiful fracturing bloom, partly due to the dialoge in this thread.

 

By the way for those not forging blooms, even a very dense bloom like the one shown will lose about 60-75% of it's volume due to loss of voids and slag.

This photo is a more realistic CO flame size (the other photo was "show time").

 

Jan

 

Thanks for posting the pictures Jan. That furnace of yours has a very simplified design which is rather attractive. Gets me thinking. Do you have chemical analysis results of your blooms? and if so, have you drawn any conclusions out of tose results that will be helpful for us steel makers.

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Thanks for posting the pictures Jan. That furnace of yours has a very simplified design which is rather attractive. Gets me thinking. Do you have chemical analysis results of your blooms? and if so, have you drawn any conclusions out of tose results that will be helpful for us steel makers.

 

 

Jesus,

 

The bloom in the photo was tested near the top (higher carbon area). Testing blooms is problematic as some of the metals (especially Al, Ti and Si) may actually exist as oxides in the flux. I will not be testing any more blooms, only forged material.

 

The results are: Carbon .85 %

Mn .01 %

P .074 %

S .015 %

Si .05 %

Cr .02%

Ni .05%

Mo .01%

Cu .01%

V .002%

Nb .001%

Ti .01%

Al .06 %

Lab comments were "sample shows heavy porosity"

 

As far as drawing conclusions,

 

a) the % Al is higher than Si, this may be due to a Si deficient slag, we will know soon.

 

B) I have read in old books, that preheating of air using charcoal was avoided in cast iron production. The lower temperatures created metal with less phosphorous. I believe this on faith.

 

c) I look at iron purity as 1 (or 100% minus the sum of all that is not carbon or iron ) so based on that definition the above iron is (100%- .312%) 99.69% pure.

 

Once I get the right metal, I plan to do a series of posts on one of these sites ( either this or SFI, I will need the help of a metallurgist ) taking the interested readers through the process of making Japanese

sword steel using the Yoshindo Yoshihara, "The craft of the Japanese Sword" ( translated by Leon and Hiroko Kapp) book as "lesson plans",if we succeed, we will all have a Japanese Master Smith we can point to as our "teacher". All Japanese terms will be left out of the text, until they can be defined in their context (frankly I don't know alot of those terms myself) .

 

Jan

Edited by Jan Ysselstein
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Once I get the right metal, I plan to do a series of posts on one of these sites ( either this or SFI, I will need the help of a metallurgist ) taking the interested readers through the process of making Japanese

sword steel using the Yoshindo Yoshihara ( translated by Leon and Hiroko Kapp) book as "lesson plans",if we succeed, we will all have a Japanese Master Smith we can point to as our "teacher". All Japanese terms will be left out of the text, until they can be defined in their context (frankly I don't know alot of those terms myself) .

 

Jan

 

 

Thank you again Jan for sharing this info. I meant to say analysis of the compacted and forge-welded steel from the bloom. Sometimes I just don't type what I am thinking. Person to person verbal communication has less missinterpretations than faceless written communication on whichever media. I wish that guys like ourselves that are interested in these kind of stuff didn't live so far away from each other. On the other hand if we did live close we may end up putting much more time than what we should into these efforts...

 

This is an analysis from one of steel bars: C- 0.865, Si - 0.38, Mn - 0.14, P - 0.013, S - 0.198, Cr - 0.042, Mo - 0.016, Ni - 0.037, Al - 0.033, Cb - 0.005, Ti - 0.014, V - 0.020, Sn - 0.003

 

Do you mean the book "The craft of the Japanese Sword"? That book is a great starting point for anything related to the Japanese sword but once you want to deepen in the knowledge the book falls short of the expectations. I'll be glad to read your impressions and recomendations as far as what you consider a good approach to making steel and avoiding making wrought or cast iron as well as limiting the amount of alloying elements or impurities.

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Thank you again Jan for sharing this info. I meant to say analysis of the compacted and forge-welded steel from the bloom. Sometimes I just don't type what I am thinking. Person to person verbal communication has less missinterpretations than faceless written communication on whichever media. I wish that guys like ourselves that are interested in these kind of stuff didn't live so far away from each other. On the other hand if we did live close we may end up putting much more time than what we should into these efforts...

 

This is an analysis from one of steel bars: C- 0.865, Si - 0.38, Mn - 0.14, P - 0.013, S - 0.198, Cr - 0.042, Mo - 0.016, Ni - 0.037, Al - 0.033, Cb - 0.005, Ti - 0.014, V - 0.020, Sn - 0.003

 

Do you mean the book "The craft of the Japanese Sword"? That book is a great starting point for anything related to the Japanese sword but once you want to deepen in the knowledge the book falls short of the expectations. I'll be glad to read your impressions and recomendations as far as what you consider a good approach to making steel and avoiding making wrought or cast iron as well as limiting the amount of alloying elements or impurities.

 

 

Jesus,

Thanks, yes that is the book I am talking about (I will edit that post) . I think there is more information in that book than I can ever process. I am not a sword smith, just a retired hobbyist who has been fascinated by steel since childhood. When searching these sites I get the feeling we are top heavy with information (I am glad about that), the Japanese terms are known by many enthusiasts (I am glad about that also). What I do not understand is, if we are all reading that the STEEL of the Japanese sword is so symbolic and significant, why are not more people going after that "process" which is now pretty well

described. Assuming a person could stick with it for a few years, the amount learned along the way would be enormous.

 

I do not have analysis of the forged steel, though I do have some results of the Wootz cakes I did a while ago, they are close, though some mixing with "Pure Iron" Bar and Wrought did occur. Send me a

PM and I will forward them to you.

 

Don't be leary of making cast iron, you need that refrence point on your process graph. Once you know how to make cast all you need to do is back off a bit or better yet switch processes during the run. For example, two additions and blowing rate as if you were making cast then one of wrought iron etc.. This is going to be my next approach.

 

Your steel looks very close to mine, I suspect there is some Sulfur in your ore (unless the charcoal was made with urethane on the pieces). The other possibility is your furnace,technically, some of the materials you are using are defied as containing no Sulfur, but who is going to look if cement has a little (from the coal used etc.) . If I had that ore I would try a wider furnace (slower descent) and see if some of that will roast off. I think your furnace is too narrow anyway and suspect the downward flow of charcoal/ore is sometimes out of your control.

.

Also if you are preheating with propane, do it with a relatively empty furnace as the mercaptains are sulfur compounds and are absorbed by carbon.

 

I hope these suggestions help.

 

Jan

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Jan, I will happy to help you with any questions you have about the Japanese terminology.

 

I think the purpose of many of us here has been to control the process using the smaller furnaces until we feel comforfortable enough with what we are doing and then scale up the size. I have been wanting to take that next step some time no. The furnace would not be nearly as big as the contemporary Japanese tatara (1 by 2.5 meters is too much for me and if I did manage to get to that size and make a bloom (kera in Japanese) then I don't know how I would manage to split a 2 ton lump of steel. I was certainly hoping to stir enough interest in people here that we could arrange for a certain someone from Japan to come over to demonstrate a real big tatara.

 

I do think that my ore has some contaminants in it. The only other suspect will be the portland cement as that contains some sulphur. I don't do the pre-heat with prpane any more. Just charcoal.

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Jan, I will happy to help you with any questions you have about the Japanese terminology.

 

I think the purpose of many of us here has been to control the process using the smaller furnaces until we feel comforfortable enough with what we are doing and then scale up the size. I have been wanting to take that next step some time no. The furnace would not be nearly as big as the contemporary Japanese tatara (1 by 2.5 meters is too much for me and if I did manage to get to that size and make a bloom (kera in Japanese) then I don't know how I would manage to split a 2 ton lump of steel. I was certainly hoping to stir enough interest in people here that we could arrange for a certain someone from Japan to come over to demonstrate a real big tatara.

 

I do think that my ore has some contaminants in it. The only other suspect will be the portland cement as that contains some sulphur. I don't do the pre-heat with prpane any more. Just charcoal.

 

 

Jesus,

 

Thanks for the offer on the Japanese terms, I agree on the small funace idea for experimenting, the cost of a small smelt is very high (not considering the time involved). By the way, the beautiful hammer in one of the above photos is not mine, the smelt was done at a friend's shop. I am very indebted to the person in the photo (he was in charge of process control that run, it was the most consistent run ever).

 

Jan

Edited by Jan Ysselstein
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Very educational, interesting and fun, as usual.

 

Could I ask a question?

I noticed the tuyeres are close to 90 deg to the stack. Same on Walter's pic. What were the considerations in using this tuyere config ? Thanks.

 

Jesus, I have a few suggestions on your brick ingredients. Substitute a high cone clay for the cement, and slightly increase the ratio a bit. Wood ash for the sand and charcoal for the vermiculite. It should insulate better and stand a much higher heat. It won't be quite as strong, but might work. Jerry

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