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I Forge Iron

minaraimono

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Everything posted by minaraimono

  1. Thanks for the article. I do wish it had about ten times as much text, but its more or less cured me of any doubt that the carbon content is homogenous in pattern-welded steel. I am, however, still really curious what is responsible for the visual layering. Just saying, "The compositions are different" hardly stands up to the scientific integrity set forth by this article. I think we owe it to ourselves to get to the bottom of it. And if there isnt anyone here who can explain this yet, maybe it will be the subject of next years Jacquet-Lucas award? I make billets of damascus out of mild/wrought iron (its carbon content is lower than standard US "mild steel" but I've never seen a spec sheet on it) and Japanese Shirogami (white) #2. The white steel is known for its high purity. It has 1% carbon, and practically nothing else. Mn, for example is .20~.30 wt%. Si is .10~.20 wt%. And seeing as Sulfur is less that .004%. and they dont even list Nickle, I think its safe to say there is'nt much. After forging and HT I don't even etch it in acid. I sand blast it. And that reveals the laters. I would just like to understand that a bit better.
  2. This has got me wondering. Im probably a little confused. I make a very simple "damascus" out of wrought iron and Hitachi White #2 (that might read something like 1095 is US terms). Now I dont fold it all that much; Im happy with about 64 layers. But after a blade from this steel is forged and HTed, I can sand blast the piece with a blasting grit that it harder than iron, but not as hard as the steel and the layers are revealed. I was assuming this was because of variations in carbon content. I'm not saying that carbon doesnt migrate. Im sure it does to various extents. But fully homogenized after 5 welds? Even with a billet that has 300+ layers, it seems that people can reveal the layers with acid etching etc. If thats not a function of the acid eating away more of the softer (i.e. lower carbon) layers, what exactly is going on in that process? Im not a serious pattern welder so I have never researched it in detail. But I should like to understand this part just a bit more clearly.
  3. This is out of my field of specialty, but perhaps I can pave the way for some of the more knowledgeable folks to post by getting things clear first. Are you talking about heating the blade for forging, or only for heat treatment (HT)? If its post forging, but pre-HT, you can really go to town on the scale without worrying about overheating. And if you do a mirror finish, thats going to be the last thing you do to the blade (post-forging, post-basic grind, post-HT) so where does fire-scale become a problem? Are you suggesting putting a coat of one of those products on it before heating it? If so, it seems pretty likely it will just burn off, doesnt it? Also, yes, setting your fire (gas or coal forge) to be "fuel-rich" or "reducing" is important if you are worrying about scale (oxidation). Again, not sure if we are talking about heating for forging or HT, so its hard to advise. If you are forge welding the blade and therefore getting heavy scale, you might find it handy to water-hammer. Perhaps there are some people who are familiar with the products you mentioned and can explain how they work. Could be I am missing something here.
  4. One option, if you don't love the idea of (A) having potential variations in carbon distribution and/or ( having a less exact idea of the composition of the material, is to laminate a single layer of steel at the core of the blade (steel section is usually about 1/3 the width of the billet). Its the favorite technique in Japan and since this is a Japanese-esque blade, I thought i might mention it. Here is an example of a single-bevel kitchen knife I made using a nickle/wrought iron damascus fire-welded to a single layer of Hitachi white #1. This way the nickle doesnt end up at the blades edge at all, but we still get the high contrast of its layers. But your piece is really hansom. The only other thing that comes to mind is: to my eye the blade line should either be a little more straight, or a little more evenly curved. Really minor though. I could point out at least as major flaws with the knife in the photo I attached. Nice job. PS sorry the photo quality isn't better. I had to push the contrast in photoshop so you could see the steel section and it all looks a little funny now.
  5. Are there any Top-level iron-craftsmen working in Turkey? I am thinking of visiting Istanbul and I was curious if there might be anyone worth visiting while I am there. Seems like the city should have a rich heritage of craftsmanship but perhaps its a thing of the past.
  6. You are right, its taking way too long to communicate this way. We could have had this settled with a 15 minute conversation over a cocktail napkin. I can't really justify spending more time on this so I'm afraid this will likely be my last post. (I only have a few months left of my current journeymanship and I want to make every minute count). The only point I will address is this: "The geometry of a blade with a flat or hollow grind allows for a more acute edge and therefore can attain a higher level of sharpness." Its the phrase that got me into this discussion in the first place, and I take tremendous issue with it. Also, it seems to be the same point that you illustrate with your drawings. Geometrically the drawings are not wrong, but they have very limited application to knife making. You assume that a more acute angle will give a "higher level of sharpness". This is not really true in practice. With any basic knife set-up its easy enough to get the edge too acute. That is, getting the material to where it no longer has enough thickness to hold a physical structure. Getting a sufficiently acute angle at the blade edge is not the issue for most people who cant make a knife sharp enough to shave with (excluding absolute beginners). And the acuity of angle is NOT the principle reason why Murray's knife shaves so well in the video. Micro structure and sharpening techniques are far more important. As I mentioned before, we make and sharpen every type of knife you can imagine in the shop where I am working. These blades have a huge range of geometry; single-bevel, double-bevel, sushi knives, hunting knives, cleavers, French chef's knives, knives designed specifically for cutting mountain-potatoes and knives for removing the poisonous livers from puffer fish!(河豚引き). We sharpen them all at various appropriate angles, and when they are done, they can take hairs off your arm. Cleavers and sushi-knives alike, dispite having very different geometry right down to the blade edge. Why? Micro structure and sharpening. I was simply concerned for beginners who might read what you wrote and think something like, " I should buy/make a hollow ground knife because it is sharper!" Or, "This hunting knife of mine could never be sharpened to a shaving edge because its convex". I suppose you will say that you covered this when you added "(but not to say that you can't get [convex knives] shaving sharp and then some)". But to add that as a parenthetical to a whole post that gives an argument for the superior sharpness of concave and flat grinds feels very misleading for beginners. P.S. I find it interesting that you chose to make the thickness at the spine and the width of the blade constant, and then work down to the blade edge (In your drawings). I would have thought about it in the opposite direction (likely the reason for many of the misunderstandings). I would start by identifying the appropriate angle for the blade edge itself and then work towards the spine with appropriate proportions to suit the knife. I know I can get a surgical sharpness on a blade held at 14-16 degrees from the surface of a whetstone. So i dont worry about trying to get it anymore acute then that. The real performance-sharpness comes from micro structure and the tools and skills used for sharpening. I have had knives that were sharpened at this angle and didnt end up taking a good edge. My boss tried sharpening it and it still would barely take hairs off. We put my blade under a microscope next to one of his blades, and sure enough, my grain structure wasnt the same. He said it looked like i had over heated it while forging, but how he could see that is still something of a mystery to me. P.P.S. The point about "micro serrations" is a good one. Lately we have been discussing the merits of matching up gain-size to sharpening stone#. for example, we only take Japanese white steel past 3000#. It holds a super fine structure so it can benefit from a super clean edge. But all of our Swedish stainless blades stop between 1500# 3000#. It has a courser grain, so its better to use the "micro serrations" to your advantage. And thats all I have to say about that. Good luck with everything!
  7. I really don't have time to spend on the internet, so I wont try to defend every aspect of my position. But I somehow feel compelled to point out a few things that I worry would be dangerous inaccuracies for beginners to be exposed to (that or I need some serious straightening out myself). 1)"Actually, flat ground and hollow ground blades have the ability to be sharper than a convex ground blade." In terms of functional sharpness of the cutting edge (i.e. a shaving test such as in this video) this is not true. In the shop where i work we make and sharpen Japanese sushi knives, western style knives, meat cleavers, hunters, skinners, you name it. Every one of them has to take hair off your head with the slightest brushing stroke or it doesn't go out the door. 2)"A more acute angle for the edge means a sharper edge. This is edge geometry." "edge geometry" seems like a wealthy way to describe the angle that the blades edge is sharpened at. It is just one angle at the end of the day. No matter what goes on above it, the edge is always just one, single, simple angle. Usually equates to between 10 and 20 degree angle to the sharpening stone. You can get this angle whether or not the blade is flat, concave or convex. 3)"Flat and hollow grinds if applied to the same blade/same dimensions/proportions will result in a more acute edge than a convex grind based solely on their geometry, you can not argue against that, and that was my point above. The geometry of a blade with a flat or hollow grind allows for a more acute edge and therefore can attain a higher level of sharpness." I do argue against this. And i hope some other people will chime in so that we can get to the bottom of it. I might be wrong, but I say: What angles and "geometry" that happens farther up the blade is ultimately very important to the performance of the blade (its torque strength, whether or not fish meat will stick to it etc) but its of minimal importance to the cutting edge . We are talking about a few thousandths of a inch here.*The angle of the cutting edge is set, as i said before, to one, singe simple ">" shape at the end of the day. Or it better be. Because is you dont set your knives to a good crisp angle, even if its only at the level of a 3000# whet stone, you are not going to cut anything. If we put a knife under the microscope to examine just the cutting edge you would not be able to see the slightest difference between a hollow-ground and a convex knife. You would only see part of the top line in this shape ">". And you would be able to see that at this magnification the edge is not such a clean pretty line. Its a bit ragged and torn. The cleaner and more even it is, the better its going to cut. And how "crisp" this edge is when viewed under a microscope has a lot to do with crystalline micro structure and the skills and tools used to sharpen it. This is a terrible over simplification, but i just dont have anymore time. PS. The choice to use no secondary bevel gives only one advantage, strictly speaking. By just laying the whole blade surface against the stone he doesnt have to rely on his hands to control the angle. Its a lot easier to sharpen, but I maintain that it says nothing about the sharpness:geometry relationship. Imagine he sharpened it like you say he does in the video. "he lays the entire primary bevel on the stone and brings it down to an edge (no secondary edge bevel), then lifts the angle slightly for stroping purposes." Now that he has the edge that he wants, lets pretend that he suddenly decided to make the knife convex! Crazy idea, but theoretically, he could change the knifes geometry without even touching the edge. The side walls near the spine would need to be thinned, but there is enough material for it. Then he would just have to preform the super-human feat of blending that convex curve down from the spine to withing some mind-boggling fraction of an inch from the edge without touching it. Not realistic, but maybe you see my point.
  8. I can tell you with some certainty that the knife in this video was not "flat" or "hollow ground". Murray is a friend of mine. He learned to make Knives in Kumamoto using the same tools and techniques that I am studying in Sakai. In my humble opinion basically none of the blade geometry described by TarAldarion above is relevant to the "cutting edge" of the knife. When shaving hairs we are talking about the last few micrometers of material! Talking about convex/concave/flat grind etc. without any consideration of the dimensions or proportions of the blade is meaningless anyway. The sharpness of this blade is mostly due to proper heat-treatment that results in a super fine grain structure that will take and hold a fine edge. Sure good sharpening skills are required as well, and Murray is one of the best. But blade geometry (as long as we are in the range of reason) has much more effect on how a blade "slices" through something, and very little effect on how sharp the edge is.
  9. I'm not actually sure I have time to comment on all of the issues that I would like to address. I guess thats what I get for jumping in so late. First, the notion that somehow, "water evaporates, generates hydrogen and 'mild' explosion results" is impossible. Steam is still chemically water, and the process of separating the H from the O requires more than hitting steam with a hammer. (electrolysis is the most practical method, I suppose). But enough about the science. There are almost certainly several things going on at once and I don't claim to understand it all perfectly. Lets just say that you can remove scale from the surface of iron/steel by "shocking" it. To do this you want to generate a large amount of steam as suddenly as possible and deliver a jarring blow. The steam is expanding, the steel is contracting and in that same moment its being whacked with a hammer. Very scientific:D. But now lets look again at what it is we are trying do. "Make a beautiful piece of ironwork" right? I think we can all agree on that; whether its a kitchen knife or a garden gate. As many people have pointed out, before you even start talking about water-hammering, you better have your fire running right AND be focused on forging quickly and efficiently. If you leave the iron soaking in the fire, or take a dozen heats to draw one tapper, there is no amount of water-hammering that can save you. For almost all general forging purposes a good stiff-wire-brush is faster, more convenient and it wont cool down your work, besides. Japanese bladesmiths use "水打ち" mizu-uchi (water-hammering) with success for several reasons. Here are just a few. The shape of the material is very uniform. Blades and billets can easily be set on top of the wet anvil and struck suddenly without fear of ruining the piece. Not so easy with a leaf that has a nice cross-pein texture on it or even a runner for a railing that will need to be perfectly straight at the end of the day. Also, they mostly use this technique when preping for a forge weld, or if the blade is "黒打ち" Kuro-uchi (black-hammered) meaning that it will not be polished all the way to the spine. This makes it very important that there be no thick scale on the sides, as the hammer texture will be part of the blades final appearance. I should also ad that I am very skeptical about the idea that water-hammering has any metallurgical benefits of its own. It should typically be done at a bright-orange heat. If you do it too hot it will start to scale again right after you hit it, but with tough scale, you might have to start at a yellow heat and keep going until it cools below oxidation. Typically the hammer, rather than any kind of mop or swab is used to put the water on the surface of the anvil in Japan. This way the hammer is wet as well. As suggested by someone previously, you dont want to set the piece on the anvil and leave it there. You want to pick it up between blows so that it wont evaporate all the water before you hit it and also so the piece wont cool down (this is a good idea any time you are working super thin stalk as well). Sword-smiths, when doing the "鍛錬" Tanren (working tamahagane into a billet by folding and fire-welding repeatedly) will set the billet over the wet anvil but with one side angled up. That is, not letting the billets face touch the anvil, only the right or left edge. Then the striker brings a seldge down on it and drives the billet down into the puddle. Personally, I use water-hammering to prep for forge welds on blades and billets, and thats about it. It can be a useful trick, and sure its great for everyone to find creative and novel applications of it, just so long as we dont lose track of the goal: "Making a beautiful piece of ironwork" and most of use can add "as efficiently as possible". There's my however-many-cents-that-was.
  10. Its time to update the prescription in my glasses, and I was thinking about moving to contacts. Before I go to the doctor, I was wondering if any one had thoughts or experiences regarding wearing contacts in the shop. Of course I would always be wearing safety glasses over them, but are there any health concerns, or other things specific to smithing that I should consider? Thanks
  11. MAN, that xxxxxx me off. I've sent emails to the American Bladesmith Society and the University of Phoenix (because that site is part of a bigger site called "Phoenix State University" which is meant to trick people into thinking its part of a real school). There is probably nothing anyone can do, but....
  12. Between the Anvil Fire articles and Frosty's post, you should have more than enough info to go on. Just remember that an anvil is no better than what its sitting on. A good stand/base is absolutely key. I know that a lot of people use them, but I highly recommend NOT using any kind of fabricated stand, i.e., steel legs. The amount of energy that it will steal from your hammer blows will cost you much more time than finding a good stump or building a sand-filled stand (in the long run). Thats all the time i have. Im sure others can add more details about stands, if you want. P.S. At age 15 the most important thing you can teach yourself is Good Posture. It is the foundation on which all skill is based. I wish I had payed more attention to it when I was your age. But its never too late...
  13. There is, as far as I know, no such book. There are not even any "how to" books written in Japanese on the subject of blacksmithing. While the Japanese language does have a word for "blacksmith" (someone who makes objects by forging iron) there is no community surrounding the craft in such broad terms. There are regions with strong traditions of making certain types of objects, for example, Sakai is famous for kitchen knives and Miki is famous for carpenters tools. Within those towns there is a network of craftsman, but they tend to keep to themselves. In fact, it can be very hard to get knife makers, chisel makers, saw makers etc. to see that they are all part of the same craft. Perhaps because so few people have back yards to begin with, the "back yard blacksmith" phenomenon does not really exist in Japan. Very few people consider smithing something that just anyone can take up. I don't know of anything written in English, but one book that might be of interest is called 日本鍛冶紀行 (nihon kajikikou): Japanese Blacksmith Travel Journal. Its in Japanese and not instructional at all, however, it has lots of pictures of traditional Japanese farm tools, and is currently in print. Its nice to see some of the iron products of Japan other than the swords, knives, chisels and planes that have become so dominate. It might be inspiring, or at least intriguing. I tried to find an English website that sells it, but failed. If you paste the Japanese words written above into a search engine the Japanese version of Amazon is one of the first hits. You might be able to figure out how to check out based on the icons, and its relatively familiar layout. (2,000 yen is about 20$ US) While I was on Japanese Amazon I did find a few books about blacksmithing that I don't yet own. None are "how to" style books but they might have some good information all the same. I will let you know if i find something good.
  14. Kalevra, ホーヒさんからメールを送っていただいてありがとうございました。 Greetings all. I am now in my second year of living and studying blade smithing in Japan and have a healthy foundation in Western style smithing as well. This by no means makes me an expert, especially where swords are concerned, but I suppose I might have some perspective on this matter. That being said, I want to stay as far away from the, "If Zatouichi where to meet Sir Lancelot in a dark ally..." scenario. I can think of several objections, but most importantly there is little for us to learn from it. With that, I would like to seize upon the last phrase offered by the proceeding contributor; "every tradition has wisdom to impart to anyone who will listen. The key is determining it from the piles of you know what that can come with it." I do believe that there is wisdom to be gained from looking at and comparing cultures and traditions, otherwise I would not be where I am as I type this. However I have the rather unlikably esoteric belief that such things ought to be experienced before they can be discussed. Rather than get caught up on ethereal Lets get back to something we can sink out teeth into. I believe this thread started with a video of three strikers working on a billet for a Japanese sword. Very quickly we get a comment on the difference in the design of the hammers being used. I think Johannes has the right of it, for the most part. Personally, I am still uncertain of the value of changing the center of gravity of the hammer if used in the standing position. The same hammer shape used while seated has a whole different story. With a few more years of research I might be able to write a book on the subject, but suffice to say, the body mechanics change completely, and the Japanese hammer takes advantage of that. I don't think anyone will find much value in using it while standing, unless you happen to be accustomed to that style of hammer already. Now I will jump to where "philip in china" adds his comments. Personally, I cant say I see anyone in this video either, " swing... just like somebody breaking toffee," or "hold both hands at the end of the handle." I see feet and hands set apart, and relatively good posture. Perhaps the fellow to the far right is doing a better job of keeping his spine straight, but I've seen worse at every single blacksmithing event I've been to (and a few better). The distance from the anvil and the hight of the swing are both different from what we are used to, but remember this is not "up-hand position" striking, and should not be expected to look like it. Considering how long the arch of the swing is (which gives them more power), they are doing a good job of hitting with positional and axial precision. Perhaps that change in handle location does help. I'm not sure. I think this technique is being utilized with attention to physical laws and body mechanics (about which if you really really want, I could offer more of my thoughts). But i think its more important that we each cultivate our own eye. Make some observations of your own and post them. Think about the basic physics at work and apply your own experience. Then we will all be able to engage ourselves in the topic, and some wisdom might just precipitate out. Personally, I only have so much striking experience, but I'm not familiar with what "philip in china" calls, "slidingthe handle through the hand on the down stroke [sic]." I think my hands stay put on the down stroke. But its been about two years since i did any striking. Please correct me if this is wrong. And to see some guys really swinging like Casey Jones, and a glimpse of similar hammers being used in the west (though for different reasons I suspect) check out this video. another group of spectacular craftsmen
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