From Scrap Iron to Sujihiki - Video WIP

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WillC

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Hello Folks, a little weekend project I have had going on. I will add some more video as I go. I think the first video is fairly self explanatory, I dont want to spoil it for you so have a watch... let me know if you have any questions. :) I will add more video and pictures as we go.
[video=youtube;OZfE73od_Lo]http://www.youtube.com/watch?v=OZfE73od_Lo[/video]
 
Thanks Guys, There are easier ways to make a knife, but this way is an interesting experiment. If its successful or not, have to wait and see, either way its a learning experience.:)
 
A lot of talk about steels and their composition goes over my head, but this sort of thing is pretty interesting and the notes help
 
Yes its a nice straight forward way to make a straight forward steel. There are a few things I had not realized until I did this which make it even cooler. You can make a very high carbon steel this way without melting anything....easily up to 1.5%C and above. I'm not sure it would become cast unless you got it super hot. The depth that the carbon migrates is deeper than I thought it might. It will be interesting to see what this steel looks and cuts like. A brief brake on a heat treated piece showed a nice fine grain in the mild steel batch and a pretty nice grain in the wrought and that was before many folds and without any heat cycling. So I'm quite excited to see if you can actually make a nice steel like this and how it will compare with other low alloy steels.
I think next time I will use some high grade Iron or pure Iron as it just makes life hard using the claggy stuff I had in the form of old barrel hoops on the shelf, but I wanted to do it with what was to hand, as part of the experiment.....
Here is a sneaky pic of the gorgeous texture on the blister steel as it comes out of the can. This is from two that had welded themselves together in the can and I broke apart.
20130326_103444_zps2234afbd.jpg

Next Vid uploading....don't hold your breath, we are still on copper phone lines here:D
 
[video=youtube;-xAcPM92HhU]http://www.youtube.com/watch?v=-xAcPM92HhU&feature=youtu.be[/video]
 
On Carbon content, I did some comparative spark testing after all the refining with some known samples. I would estimate the carbon to be above 0.9% and below 1.2%. But the proof is in the pudding, the long pointy pudding:D
 
Will I have been admiring your work for a very long time, and this is one of the most exciting things I am looking forward to. Thanks so much!
 
Thanks Don you are a gent, your enthusiasm is most welcome:doublethumbsup:
I'm excited about making a hamon on it. I have not done much with shallow hardening steels before so that will be a new thing, though i've made hamon by accident before in W2 damascus.
From my reading, grinding the bevels at least some of the way before the quench will help the hamon as just the edge being thinner and the spine thicker will make different hardness's, assuming the steel behaves as a shallow hardening one.( I would normally taper but not grind the bevels until after HT) I will clay it up of course, I'm going for a warm water quench, in the bosh on the back of my coke forge.
Any last words or advise?......:D
 
Thanks for posting the videos. I am absolutely fascinated by your process. Looking forward to seeing how it comes out.
 
Annoyingly, it did not harden, well not fully in any case. There are quite a few things which could have gone wrong but I have a feeling the iron needed a longer soak and after all the folding there was not anywhere near as much carbon as I predicted. I will be trying again with just pure iron as using both mild steel and iron in this batch made it even trickier to work out what went wrong. Ah well we live and learn...
 
The school of hard knocks is a very expensive way to get an education. Sorry this happened. Thanks for doing this for all of us. I heard once that charred bone works best for carburizing. Good luck.

Love and respect

Hoss
 
Yep, a bit more magic in the compound I think....and a longer soak. The wrought had distinct blisters on the surface, the mild, none, though both spark tested on the surface showing carbon, perhaps the iron can take the carbon more readily, I was worried about using the mild steel because of unknown quantities of alloys....
So it will be a bit more controlled next time with the pure iron, which I will know the specific chemistry.
For those wondering the difference between wrought and pure iron. Wrought is the "old stuff" Smelted from ore, worked in a bloom, then rolled and re-rolled to a specific grade. So wrought iron is all very old as it is not actually made in any quantity any more, though it is collected and re-rolled.
Pure iron is a modern product. I presume a crucible melt with alloys and impurities added to approximate a sample of wrought iron, then rolled to product. So it wont have the strand type grain of old iron as it has not been refined by rolling and re- rolling. Its more uniform. So could be a better bet for this type of experiment.
Here is what is in it, which you may also find in a sample of well preserved wrought, though they are very different materials to work with.
http://www.pureiron.co.uk/technical_data.htm

Thanks Hoss for spurring me on, I will try again one weekend soon:doublethumbsup:
 
I tried making blister/sheer steel last fall and took a bunch of pics for a potential wip and mine ended with the same result of yours. I only cooked it in the forge for a few hours and did not get the carbon penetration needed to harden. I read a recent wip where the maker put the iron in a wood stove to carburize for upward of 12 hours. Rick Furrer (sp?) on Don Foggs forum has done classes here in Maine on how to do this, but I missed it. Good Luck.

John
 
Yes its a nice straight forward way to make a straight forward steel. There are a few things I had not realized until I did this which make it even cooler. You can make a very high carbon steel this way without melting anything....easily up to 1.5%C and above. I'm not sure it would become cast unless you got it super hot. The depth that the carbon migrates is deeper than I thought it might. It will be interesting to see what this steel looks and cuts like. A brief brake on a heat treated piece showed a nice fine grain in the mild steel batch and a pretty nice grain in the wrought and that was before many folds and without any heat cycling. So I'm quite excited to see if you can actually make a nice steel like this and how it will compare with other low alloy steels.
I think next time I will use some high grade Iron or pure Iron as it just makes life hard using the claggy stuff I had in the form of old barrel hoops on the shelf, but I wanted to do it with what was to hand, as part of the experiment.....
Here is a sneaky pic of the gorgeous texture on the blister steel as it comes out of the can. This is from two that had welded themselves together in the can and I broke apart.
20130326_103444_zps2234afbd.jpg

Next Vid uploading....don't hold your breath, we are still on copper phone lines here:D


Hi, Will. I am a new comer to the forum here.:)

I have admired your work for quite some time now. The knives you made are just exceptional! And there's nothing more exciting than checking your new work on this board every other week. :)

Alright, let's get back to our subject... blister steel :angel2::laugh:

On your experiment... from the cut-open BLUE colored blister steel picture you took, I think, it probably gave a hint on why the quenching failed at the end (not enough carbon). The blue color might not be the right one your are looking for, and it should have been pink or yellow color. I could be wrong on this... but, doing some reading on Japanese Kera (steel bloom from Tatara Smelting) color could possibly point you to the right direction. Please take a look at the google books link attached at the end of my post, the book title is "The Art of the Japanese Sword" (only sample pages are available, but it's already good enough), pay attention to the section that describes the 5 different colored regions of Kera,

1. Yellow, Tamahagane, carbon 0.5 - 1.2;
2. Pink, Owarishita, carbon 0.2 - 1.0;
3. Blue, Hobo, mixture of Tamahagane and IRON;
4. Grey, Noro, mixture of slag, steel, iron, and impurities
5. Green, pig iron, carbon 1.7 and above;

In later pages, there's also a close-up picture of 3 good Tamahagane pieces taken from a Kera, it demonstrated a lot of the yellow color and some pink and blue spots.

Other than the coloring, like you suspected... the iron pieces used in the experiment might have been just too thick and the soaking time was not long enough.

In addition, besides the blister steel method, there are also other ways to carburize iron to steel. In contrary to the common believe of Tamahagane must be obtain from Tatara smelting, Japanese from ancient times actually made small quantity of it directly from a smith forge by melting and carburizing salvaged iron objects... The book I linked has this info also. In the later pages, there's a section explains "Making Tamahagane in the Forge". Maybe it will give you some new ideas (with less trouble)? :wink::)

http://books.google.com/books?id=UR...ce=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
 
Thanks for that Mr Clinton, it was rather puzzling why the piece would not harden. Looking back on this I think it was actually a heat treatment problem. As the piece sparked well, showing carbon and diffusion should have been complete after all the folds. I think I did too many heat cycles on the piece and it would not harden. As I'm used to oil hardening steels. Having done a bit more recently with water quench steels I think this could have been the case. I think the next experiment of this nature will be a smelt under the guidance of a friend who has much experience of making steel. Thanks again for your comments:)
 
Thanks for that Mr Clinton, it was rather puzzling why the piece would not harden. Looking back on this I think it was actually a heat treatment problem. As the piece sparked well, showing carbon and diffusion should have been complete after all the folds. I think I did too many heat cycles on the piece and it would not harden. As I'm used to oil hardening steels. Having done a bit more recently with water quench steels I think this could have been the case. I think the next experiment of this nature will be a smelt under the guidance of a friend who has much experience of making steel. Thanks again for your comments:)

It's very nice to see your reply too, Will. Your answer is short, but very informative. It helped me to learn something new as well. So, thank you also. :wink:


I agree the piece indeed had enough carbon (after multiple viewing of your wonderful youtube clips). With some more checking on the web, I also ran into this discussion on another board, one of the subject covered is similar to what you have suggested-- water quenching. :lol2:

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=110;t=003022;p=1

On page 2, according to Scott Roush's original words,

"It hardened wonderfully after 5 tries..turns out the austentizing temps are WAY above most steels. It also got an awesome spontaneous hamon (without clay) but it's hard to see with the 600 grit polish and the patterning."

It seemed that he had the exact same problem, and had to do it 5 times to find out the right temp. Yikes. :clown:


Anyways, carburizing is the key process involved in making blister steel. So, in theory, the type of color shown on the surface (or type of color pigment) of the finished product should be similar as along as carburizing process was used (e.g. blister steel, traditional Japanese Tatara smelting, smith forge carburizing).


Regarding smith forge made Tamahagane... I was a bit careless, and didn't realize the book I linked had those critical pages omitted. Sorry about that. :O

On the other hand though, before digging into the real deal of smelting, I do have some good links on smith forge made Tamahagane for you. They should give you most of the hints you need on making high carbon steel by using just a simple charcoal furnace. You can do it outside your workshop (while at the same time carry on with your regular work). Give me a day or two to post, as some of the links will require a tiny bit of translation, but my Japanese is extremely limited (or close to none. :bigeek:). Hopefully, after viewing these, they will put a good smile on you. :wink:

By the way, you can just call me Duckbill, or DB. I got this nickname from my old work... It's weird, but it reminds me of lots good memories. :laugh:
 
ok, writing in multiple posts, here we go. :)

Some background info... Lots people have heard of the term "tamahagane", in Japanese, it means precious steel (and nothing more), and usually, it refers to high quality steel bloom with high carbon contents. Being brought up from eastern Asian culture and knowing a tiny bit of Japanese… so... just my honest personal opinion, the term "tamahagane" does not necessarily imply smelting process must be involved, but rather, technically, any carburizing method produced high carbon steel bloom with little impurities can be called “tamahagane”.

Refer to the book link I posted previously, in ancient times, “tamahagane” is very expensive and not all blacksmiths can afford such material. Sometimes they would have to create their own salvaged steel--“oroshigane” by carburizing recycled iron objects in their charcoal forge. With proper techniques, the quality of “orishigane” obtained could match that of “tamahagane”. Carbon content wise would be similar, and purity wise could be even better depending on the type of salvaged iron used.

Still though, I respect the idea of “tamahagane” should be obtained from “tatara” smelting, and traditions shall be honored. In modern day Japan, swordsmiths also honor this tradition, and for most of the katana forged, (depending on lamination type) the cutting edge must be forged from genuine “tamahagane” or its “mixture” (forge weld) with “oroshigane”. (The youtube links I post below should explain this very well.)

Ok, the 1st example, a post-World War II Japanese documentary dubbed in English, so it’s very much self-explaining. To date, IMHO, this is the most accurate and direct depiction of how a katana is being made (no artistic editing, no exaggerated descriptions, no fancy story telling).

[video=youtube;f7z9pkQnz_0]https://www.youtube.com/watch?v=f7z9pkQnz_0[/video]


(Please pay attention to portion when the swordsmith turn iron tea pot to “oroshigane”.)
 
For the next example, only Japanese is available. The title translation would be “Japanese legend: Katana”. It was produced in 1995, and is a 2 part YouTube post.

[video=youtube;mkHrcCzswpk]https://www.youtube.com/watch?v=mkHrcCzswpk[/video]
[video=youtube;RGFuJiDUEPM]https://www.youtube.com/watch?v=RGFuJiDUEPM[/video]

Please pay attention to Clip 1, starting from 30”, swordsmith heat up and forge wrought iron objects to thin strips, cut to small pieces, melt and carburize them in forge, around 2’21” the bloom is produced. Both swords made from example 1 and and 2 are of "Honsanmai" construction.
 
The 3rd documentary is also in Japanese only. The title translation would be “Swordsmith’s Challenge”, and is a 4 part post. (Though all the YouTube links posted so far are katana forging related, let's still focus on the making of “oroshigane”.)

[video=youtube;0iLyqwXUrh4]https://www.youtube.com/watch?v=0iLyqwXUrh4[/video]
[video=youtube;0zq5zXfIQBs]https://www.youtube.com/watch?v=0zq5zXfIQBs[/video]
[video=youtube;f3SV9pR7Pjc]https://www.youtube.com/watch?v=f3SV9pR7Pjc[/video]

Clip 1, from 8’54” to 11’15” showed how “oroshigane” is being made directly from iron nails (no forging required).

There are several things made this documentary more interesting. Iron nails used in the "oroshigane" process are 200 some years old and were collected from a nearby ancient temple during its repair/ renovation. The bloom was used to recreate a katana that resembled the same type of steel texture/ pattern and hamon from the same ancient period. The finished sword would be a tribute to the temple. There were 2 major challenges for the swordsmith, the first would be the steel texture. He solved it by forge welding/ folding “oroshigane” (mid carbon) with genuine “tamahagane” (high carbon) to recreate the pattern. The second challenge would be the unique hamon pattern, with some trial and errors he figured it out. The katana he made seemed to have no lamination involved, and could be just “Maru” (mono steel) construction.

(Please note that my Japanese is extremely poor, so corrections are highly appreciated. :) )
 
Part 4 of the 3rd documentary (forum restricts only 3 video links max per post).

[video=youtube;XGUe7_MG6do]https://www.youtube.com/watch?v=XGUe7_MG6do[/video]
 
The next and final example will be of American origin. The way the blacksmith did was quite legit, easy, and straight forward, and really, it should put a good smile on you (as you don't have to dig into the rather complicated tatara smelting process). :) It’s sad that a number of people on YouTube are bashing him on this. These people thought they know “tamahagane”, but indeed they don’t.

By the way, one important thing I would also like to point out (which the author didn’t) is that the tuyeres position is vital on controlling carbon content in the bloom. If the tuyeres are very close to the furnace bottom, atmosphere would be oxidized and the bloom quality will be low. If the tuyeres are set too high, then the melted iron will have too long of a distance travelling down, too carburized, and may turn most of the bloom to cast iron. (Air flow rate and temperature are important also.) However, after a few simple tries one should be able to figure all these out. Really, truly, "tamahagane" quality blooms can be obtained from this method. :)

[video=youtube;5vIJu1ms2sw]https://www.youtube.com/watch?v=5vIJu1ms2sw[/video]

Once the bloom is produced, please refer to the Kera color coding I posted early for quality checks. Oh, by the way, if the bloom obtained is too carburized, don’t worry. There’s an easy way to fix that, but it would be from an ancient Chinese origin. If needed, I will post some short hints here also. :)
 
Very interesting posts DB, many thanks for taking the time to contribute. I have been to a few smelts at my good friends Owen Bush's forge in Kent. He has got his production pretty well sussed as to what goes in and the amount of decent carbon steel produced.
My knowledge of it is very limited but from what I gathered it is the amount percentages of materials fed into the smelt which give the results. I.e too much charcoal to iron rich materials, you would have cast iron. The position of the Tuyere is important when it comes to allowing the slag to separate from the bloom at the latter stages of the burn.
Owen has been using various sources for his raw iron, including iron rich sand, and more recently a vain of iron ore located in Kent, which is a nice touch, charcoal for the carbon content. He builds the furnace up out of clay mixed with straw. Interestingly recently he has been using a solid copper Tuyere and has a little glass sighter set up on the burner to get a visual gauge of temperature.
I have been talking to Owen about making some steel which I can use for a few one off kitchen knives as a special project. I think you can expect something like around 0.8% - 1% C after the higher carbon pieces have been further purified by multiple foldings with iron with all being well.

I would love to get something with an end result of around 1.5% carbon, but I think looking into a micro crucible method would be the way to do this.

Here are some pics I took from the last Smelt at Bushfire Forge in Kent.











This smelt produced around 6 Kilos as I remember.
 
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