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Tim Mitchell

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Everything posted by Tim Mitchell

  1. Hi All, Here is a really information packed paper by Manouchehr and Niko published in 2013. It has lots of good information and it gives many areas for wootz makers to ponder in their processes etc. Niko and Manouchehr has done a fine job on this and it is good for Niko to share some of his journey in trying to get the best pattern that he can. Thanks Niko for sharing! Link to paper is here: Niko Paper Summary of elements from the paper: NIKO METHOD: Suspicion that Phosphorous creates a stronger pattern (approx 0.16% P) Crucible Charge: - 1155 g rust free bloomery iron - 1079g cast iron (calculated to 1.5%C) - cover charge with 230g of crushed green glass (or his flux mix) Firing stage: - Place crucible in gas furnace - Preheat for 15 minutes then raise to 1600°C - Fire for 90 minutes - Turn off furnace and let sit until crucible is 1000°C (about 2 hours) - Remove crucible and allow to air cool Forging stage: - Bake ingot at 1100°C for 3-5 hours then start forging immediately without cooling stage - Forge above Acm so cementite can move (too high causes problems with pattern) (Acm is 960 °C @1.5%c) - Forge ingot flat like a pancake, - When 15mm in height bore a hole in the centre and use drifts to create a doughnut ring 20mm thick - Cut through ring and open out into a bar (this Doughnut technique is Niko's original method and a real cool one too!) - Use Ball Peen hammer for curved face during this stage forging both sides - After each full pass, file or scrape a very thin layer off the surface of the bar while the steel is still hot - Forge down to blade thickness - Keep blade stock removal to a minimum
  2. Hey Owen, thanks for that, I knew from Al that there was someone in the UK that he was mentoring. I didn't know a name. I will add them to the list. I wasn't debating the difference between melt and smelt.... they are two different things as you say, I was making a snide comment about where the smelt stops and a melt begins.... I don't think that a newbie would immediately understand the difference between melt and smelt easily, but now that these comments have been made... thanks guys.... they will have a better idea of the difference. Hey Mark, as you suggest it is rather more involved than that, with little differences including impurities making a big change in steel patterning or quality. The purpose of doing the summary is to help people to see the method at a glance and then look at the finer details if they wish. It is a place to start experimenting and asking questions.
  3. Niko, Some really lovely patterns there, it makes me eager to get back into forging myself. I have noticed that the more ingots that I forged out, the better the patterns got. Funny how that happens. Good work, keep it up Mate! Tim.
  4. I thought I would share this paper from Klaas Remmen, Thanks Klaas! It is a really good write up on the Georgian Crucible Steel process. The process is from Zaqro Nonikashvili. Good work Klaas and Zaqro! It is well worth a read. LINK Summary of process in paper: GEORGIAN METHOD: Crucible Charge: - Take one clay crucible, divide low carbon iron or pure iron charge (300g) in four equal parts, place two parts of the iron charge in crucible - Cover with layer of sand or crushed glass, - Place 10mm layer of charcoal on glass - Place one part of iron on charcoal - Place one part of charcoal, another part of iron - Finally place one last part of charcoal Firing Stage: (ore reduction) - Fire for 1.5 hours at 1500 °C in Gas forge - or in coal forge, raise slowly to temperature, cover with anthracite coal or coke, cook for 1 hour and let cool, remove crucible after 1 hour. Forging Stage: Zaqro Nonikashvili forging method from other discussions: Thread Link - Heat ingot to 1150 °C for 30 minutes (Agr is 1050 °C @1.5%c) - Let cool on anvil to an orange heat - Strike gently with a few blows on one side at first, return to forge and turn ingot over - Forge between 800 °C and 1000 °C (Acm is 960 °C @1.5%c) (A1is 727 °C @1.5%c) - 65 heat cycles to forge a knife blank
  5. Well done Jan, it will be interresting to see how you go with forging the ingots. I find if you get the melt a little too hot you can have voids forming in the ingot like you have there, often they then fill with carbon, and so you have to forge them as high as possible to be able to close them. I would forge the ingot and get it soft before I try to close the voids or you risk not having them close or cracking the ingot.... I generally haven't had success in closing the voids, although I have heard some do have success on occasion. Hopefully you can make something workable from those ingots. Don't rush the forging, the slower you go and the less force you use initially the better your result will be in my experience. Sorry to hear about your forge, hopefully you can fix it, for first time forging of Wootz I find that it is better to use gas as you can control the atmosphere of the forge and the temperature much better. Happy forging!!
  6. Mark, thanks for sharing the pic, yes the structure does look a fair bit like some of mine. I do mine two different ways to get either your the dendritic pattern or to get the more traditional pattern, and as some note you can get a more dendritic pattern on one part of the ingot and a more watered pattern on another part, wootz is tricky stuff. Some of the old blades showed pretty strong dendritic patterns too, and I don't think we should get to the stage on this list of accepting only very watered patterns as wootz. I suggest that you get some more durable crucibles and continue playing around.... Zeb, thanks for your thoughts, you do make a good point, however we could debate about what level of charcoal added to a melt turns it into a smelt..LOL... Is it a common thing these days to refer generally to all processes as melts? Thanks for sharing about your smelting method from Jeff Pringle, perhaps we could get Jeff to share a brief summary of his process (smelt and forge) so we can list it as Method #2. When you get the forging down and are able to make some blades we can pop you on the list! Keep experimenting.... Jan, thanks for mentioning Ivan, I wonder if he has a site hidden somewhere? Keep the posts coming guys!
  7. Thanks for the correction Tim, don't know why I put MN... He has some really nice skills and has done a huge amount for the wootz field.
  8. Hi Dmitry, thanks for putting your name down, you make a good point about asking if it is OK first, however if someone has a website or posts online that they make their own wootz, then they can't have any objection about being on the list now can they? All the people currently posted have a web presence concerning their wootz work, either forums, publications or website. What I mean about sharing methods etc. is that when I first started out making wootz ten or so years ago, there were only two methods to decarburise an ingot (acid, baking in an oxidizing atmosphere), two methods to melt (open crucible, closed crucible) with a gas or charcoal furnace; only one standard crucible charge, and two different methods of forging the ingot to get the wootz pattern. Things have changed a bit since then and it would be good to have a public record of how things have changed. It is very simple to list a method of making wootz, which those who are familiar with the process can understand. Let me give an example...... Method #1 Crucible Charge: - Clay Graphite crucible - Charge with Sorel cast iron and atomised iron powder mixed to 1.7% carbon content - Add flux of crushed glass and 1" square of charcoal with green leaves - Seal Crucible with solid lid Firing Stage: (melt process) - Fire crucible at 1450 deg C for 1 hour in Gas furnace - Turn off furnace - Cool in furnace overnight to allow proper dendritic growth Forging Stage: - Cycle half ingot in oxidizing flame 6-8 times above Acm (Acm is 960 °C @1.5%C) - Forge in carburising or neutral flame between 850 and 950 deg C until 1cm thick forging equally both sides (keep below 950 deg C) - Grind off decarb and forge out blade Heat Treating Stage: - Heat blade to 950 deg C and quench in heated transmission fluid - Temper at 450 deg F until straw colour - Acid etch in Ferric Chloride to reveal pattern. There you go, that wasn't too hard and it didn't reveal any little secrets either. There are other methods of charging crucibles such as the Georgian method etc. which have come to be talked about in the past years. All I am suggesting is that we do what I have done above for the different types of methods that are out there. There is plenty of room for people to not give their little secrets as this is just general method that we are talking about here. Unless all the wootz makers out there have become snobs... which I know is not the case, we should be able to create a useful sort of record of current methods of wootz production for the wider community, afterall it is about keeping the knowledge alive and helping others to experiment and improve their skills. This sort of record does nothing to harm those like Ric who are running classes in wootz making, as there is a lot in technique and experience that can only be taught one to one or through hard work. I encourage those who use a different method to that listed above to list their method in the same style, omitting any major secrets, but giving the general process. Happy Forging, Tim.
  9. Let me start the ball rolling, these are listed in no particular order. I will edit this post with all new names and links as they are posted, so we have them all together. Post Country and State if possible. Also can you mention what year approx. you first started making wootz please? Al Pendray - US - FL JD Verhoeven - US Richard Furrer - US - WI http://www.doorcountyforgeworks.com Tim Mitchell - Australia - NSW http://www.buffaloriverforge.com Achim Wirtz - Germany Greg Obach - Ontario - Canada http://www.northshoreforge.com/index.html Jeff Pringle - US - CA http://vikingswordsmith.com Larry Harley - US - TN http://www.lonesomepineknives.com/ Heimo Roselli - Finland http: //www.roselli.fi/ Vasily Fursa - Ukraine Dmitry Malakhov - US - WI www.artandknife.com Ivan Kirpichev - Russia http://ivan-kirpichev.ru Evrahim Baran - Belgium http://www.evrahim.be Mark Green - US - NC Dr. Zaqro Nonikashvili - Georgia Klaas Remmen - Belgium (on this forum) Cyrus Haghjoo - Germany http://www.cyrusblades.com Niko Hynninen - Finland (on this forum) Peter T. Swarz-Burt - US - CT http://www.dragonsbreathforge.com Doc Price - Plymouth - UK Colin McIver - Herne Bay - UK Niels Provos - Mountain View - CA- US Regel Jean-Louis - France (on this forum) Adam Adamski - Poland http://forum.knives.pl/index.php?board=195.0 Arkady Dabakyan - Prague - Czech Republic https://www.facebook.com/pages/Arkady-Dabakyan-Wootz-Knives/305717482778765 http://www.kovar-a.cz Fabian Damanet - Belgium (on this forum) Jokke Lagerspets - Germany (on this forum) Miquel Segura - Barcelona - Spain (on this forum) Abdulrahman Jafar & Awni Hapaq - H.K.Jordan - abduja@hotmail.com Sergey Lounyov - Russia
  10. Hello All! It has been quite a few years since I have been involved in the Wootz community. Not due to lack of interest, but due to health and not having an area to work. From glancing around the pages, it seems that there has been quite a lot of experimentation from all over the world, with some very nice looking results. I am gearing up to do a lecture and demonstration over here in Australia for the guild on Wootz production, and was thinking I would like to take the pulse, so to speak, of Wootz making around the world. If you all don't mind could we: 1. Make a list Wootz makers in the US and internationally (will all wootz makers put their hands up please...LOL) (please link to a website if you have one) This is ONLY those who smelt their own wootz and make knives from them. 2. Make a simple survey of the current methods of smelting, ingredients, and forging of wootz (times and temperatures etc) Please try to keep things as simple and as short as possible. Also please try to not post a name or method that has already been listed. I hope this will be of help to the whole wootz making community and is something that it would be good to regularly update. Happy forging, Tim.
  11. Thanks for sharing some footage of your class, it looks like a good time was had by all. It is good to see the know how being shared around. Keep up the good work.
  12. Congratulations Cyrus, it looks like a nice piece of steel. Good Work, it is very satisfying to get to this stage. I think that this won't be your last ingot, welcome to the journey. I look forward to seeing the finished item. Tim.
  13. Jan, The Black Wootz is what is known as Kara Khorassan, it has a very distinct watered pattern and is one of the destinctly Persian patterns. It is called Black Wootz because most of the carbides form into cluster sheets and show up as silver lines, and the gaps between the lines are basically black. It means that the piece of steel has very good separation of carbides into sheets and that the sheets are rather dense. If there is poor separation of carbides, some will stay in between the sheets and will cause the steel to have a greyish look, although the pattern is the same. The lines can vary in thickness and in spacing between different pieces of steel. The Pattern is also different from the other patterns in that it has only wavy lines on the surface, and no straight lines from dendrites are visible. On examining the steel cross section under a microscope the carbides form perfectly straight lines with no irregularities to them. Tim.
  14. Jeff, I can assure you that it can happen and does happen, although often it is visible only via magnification. As to the exact mechansim through which it occurrs I don't claim to know precisely, I can only guess. I wouldn't mind knowing though. I have seen it under the microscope and also Al assures me that if you don't do things right it can happen. It happened in my first ingot and I have no doubt that it was carbon that I was looking at. If you do things right it shouldn't happen though. I haven't seen it in the metalurgy texts either, then again not everything is in there... and even less in my head Cheers, Tim.
  15. Hey Jeff, I have read verhoeven's paper, thanks. It is not bad but there are lots of things that he didn't say. When you do the bake to Achim's specs you raise the steel to the point that the carbon goes back into solution fully in the metal and migrates evenly throughout the ingot, as you do the slow cool the carbon will form in any tiny holes in the ingot, or any cracks that are in there. (it will also happen when the ingot is cooling after the melt) It may be something other than carbon, it is just that tiny voids are not very uncommon in this type of ingot, especially if you get the ingot too hot and boil it a bit. My first ingot showed the same type of thing. Al Pendray has assured me that it does happen and it is carbon that forms in the small voids in any ingot of this carbon content steel. Most ingots have very small voids, some that can't be seen with the naked eye, often I see the voids in the finished blades of people as little pin pricks in the surface of the blade. It is often very difficult to get rid of the voids when they are there. Cheers, Tim.
  16. Hey Cyrus, It looks like you had a few small air pockets form in the ingot during the melt. As you bake the ingot any holes will fill with carbon and create spots like you see there, I think you mentioned that this ingot had been baked already. I don't know if that is what happened there, but I do think it is quite probably what you are seeing. The only fix is to forge it at the top end of the forging range, which if you are lucky may close the voids as the carbon migrates out of the pockets. The worst case senario is that you will get some blades with a little carbon spot here or there. Good Luck. Tim.
  17. Jeff, The scale is exactly what I am meaning, with the dendritic pattern you see a larger scale of pattern the more you forge it, just like zooming in with a magnifier. The more you forge the more you zoom in on the visible pattern. Big thickness reduction big magnification of the pattern, small thickness reduction, small magnification of the pattern that is there. The pattern is always there just not as visible. With the Black Wootz pattern there are no visible dendrites, just cluster sheets, and as you do the thickness reduction, you are zooming in on the pattern, so it is easy to never see a pattern if you either don't do enough reduction with forging or if you don't forge enough on one side. It just doesn't zoom in enough, if you look at it under magnification it is still there, you just can't see it with the naked eye. I wish I did have some pictures of the developing pattern, it would mean much forging and finishing and reforging then refinishing, which I haven't done, I have noticed the differences between two pieces next to each other in a bar when I treated them different. I must do something like that in the future and take pictures. We will see what happens. Now did that help, here's hoping ... there is so much going on that we know so little about, we just get a bit of a glimpse here and there. Some can be a little hard to discribe or to get your head around. Cheers, Tim.
  18. Hey Jeff, What I meant was that as you forge the ingot, the pattern expands as the metal expands and is drawn out in both directions. That means that the thicker the ingot and the more it is reduced, the stronger the pattern you will see. If you forge the ingot on one side predominately, the pattern will expand mainly on the forged side and will be most visible on that side. Depending on how strong the pattern is to begin with, you may not even be able to notice it on that side. The pattern is always there, but it may not be visible to the naked eye. This is more of a problem with the smaller ingots and also with the Black Wootz style of pattern (Kora Kharasan) , I have had the pattern only show up on one side becouse I didn't forge it evenly. It does not tend to be as much of a problem with the dendritic wootz patterns, but is still noticable in the boldness of the pattern. I like to cut the ingots in half and then just forge them flat, that way I have less waste, but you have to be careful about reducing the thickness enough so that a good pattern develops. Seeing I do all my ingot forging by the good old fashioned 16 LB hammer , it works for me. If I had a power hammer I would probably forge the ingots a bit differently. Hope that helps, Cheers, Tim.
  19. Good Work Cyrus, it is a good feeling when you get a nice even melt and strong dendrites on your first ingot. As the other guys say, the hardest part is yet to come. You have to really watch your temperatures or you can kiss the pattern goodbye. Hit it a few times and throw it back in the forge. I can't wait to see what you end up with, it is lots of fun and you usually get surprised. Oh by the way, make sure that you work the ingot evenly on both sides so that you get even expansion of the pattern on each of the sides. If you don't you will end up with a pattern on one side only. All the best, Tim.
  20. Good job Kerk, it can be frustrating sometimes trying to get a homogenus ingot, and no air bubbles. Just remember to forge it slooooow, much slower than you think. You don't want to crumble it at this point. I would grind out the unmelted section first though, to give a more constant pattern in the finished item. 850-900 deg C is usually a good place to forge them at. Don't let it get too cool or you will have a cracking ingot. The center of the ingot looks like it has more cast iron in it than the rest of the ingot, that may cause problems with forging. The whole ingot should look like the bottom left corner, homogenous and nice bright carbide lines. I use crucibles direct from Bartley Crucible and Refractory, If you buy them in bulk they are much cheaper, I seem to remember a bit over $200 for a box of 12 clay graphite crucibles, and I get three or more melts from each one. Lids are available too. It makes for cheap ingots. Otherwise you can buy them singly from a distributor like http://www.budgetcastingsupply.com/Crucibles.html Bartley Crucible and Refractory Inc. 15 Muirhead Ave Trenton, NJ , 08638-5134 Phone: 609-393-0066 FAX: 609-393-1866 I think their minimum is one box of 12. For your next melt keep the crucible away from the blower inlet and let it sit longer ( a clay graphite crucible will help). You are trying to learn two arts at the same time and get them both right at the same time, I would buy a single clay graphite crucible and cut down on the things that could go wrong. You are on the right track, I wish you all the best.
  21. Thanks JM, I have been adding a bit to the site here and there as I get time, it still has a way to go. Tim.
  22. JJH, no Al Pendray and JD Verhoeven have not done a complete step by step tutorial, and are not very likely to do one any time soon. There is so much involved in getting the pattern they do, even Al doesn't get it all the time. Getting the ingot is the easy part. It is how you treat it afterwards which gets tricky. That doesn't mean that it is too hard to get the dendritic wootz patterns as are found on the Indian swords, the Turkish and also some of the Syrian. You just have to watch your temperatures. I have a cheap type N thermocouple in my gas forge which makes it easier to keep an eye on the temperatures of forging. Dave, I suggest you visit Vasilly Fursa's site http://www.geocities.com/qasruf7/bulat.html, he shows pictures of a charcoal furnace (not forge) he made to make ingots. I know of no general forging gas forge which has a large enough burner to heat up a crucible and melt the metal. It requires either coal and forced air, or lots of gas with forced air. I have no experience with the fogg forge or the size of it's burner so I can't comment about it. It is almost impossible to buy the powder in small quantities, the smallest quantity that Hoegenes sells their atomized iron powder in is 700 LBS if I recall. Also the Sorel metal (pig iron) is hard to come by, you will need to call all of the foundries in your area which make ductile iron, you may get lucky. It comes from Canada and is only needed for the trace levels of Vanadium. IMHO the best way for you is to get any pure hard cast iron (of known carbon content) from a local foundry and then add an appropriate amount of 1010 or 1095 etc. in a weight proportion which gives you between 1.5 to 2 percent carbon for the mix. You will need to locate a small quantity of vanadium or manganese from a supply house and add enough to make the mix .0001 % or so (barely a pinch). Your furnace needs to get up to 1400 degrees C and sit there for around one hour. The plant material just needs to be there, pick some leaves off the nearest tree. Just put them in whole or crush them and stuff them in, you only need enough to cover the metal. You can get crucibles of various sizes and small quantity from Budget casting supply Lids are also available for the Bartley clay graphite crucibles. Crush the glass up and place it on top then stick the lid on. Also check out this wootz tutorial at primal fires. By the way DO NOT under any circumstances use ceramic wool blanket uncoated (it needs a solid high temp ceramic refractory coating) in a smelting furnace, the heat causes the particles to break apart and it will fill the air with nasty fibers which will catch in your lungs and can be like asbestos. Also it will cause your housing to melt like this. This was my first furnace, thankfully I wasn't hanging around it much during this event. It was force fed by a shop dust collector blower. That is a popcorn can, and the burner had a cast ceramic flare on it which looked like melted cheese by the end of the firing. Happy smelting, it is lots of fun. Tim.
  23. Hi Kyle, the Red Gums which I am familiar with have greyish smooth bark in the upper portion with some darker coarse bark lower down, if it is all ridged bark then it is a box tree not a gum. The wood when fresh has a dark red-orange look which changes to deep red as it dries out. If it is lighter orange then it is probably something else. All gum trees have smooth bark for most of the tree, the boxes have coarse ridged bark all the way up although the leaves look similar. Hope that helps. Tim.
  24. Hi Jeff, the ingredients are sorel metal (pig iron from Canada) and pure iron powder (atomized iron from hoegenes) ground up glass and some leaves with a small lump of charcoal. Hi Ric, the etching process is this. I finish grind my blades and then go over them with 400 grit emery. At this stage the carbides are exposed and if I was to light etch it at that point with the blade unhardened the pattern would be the usual diamonds in pudding (to quote yourself). I take the sanded blade and harden it in a forge with a slightly oxidizing flame, this etches the outside a bit by pulling the carbides out of the surface of the blade. The surface of the blade is at this point decarburized a little and where the pattern of carbides were, is now a pattern of little pits. I temper the blades and then etch them in ferric chloride for an hour or so, or until the etch is deep enough. Periodically throughout the etch I will take some 1000 or 2000 grit emery and rub the surface of the blade to give me an idea of how deeply the pattern has been etched. The blades seem to be much more resistant to rusting after this process (all except the sharpened edge), and the deep etch gives a much more durable pattern surface for a working knife. As I said before, the pattern is now in reverse, the white dots are now black and the black steel is silver. The Red Gum looks kind of flat if it doesn't have any figure, but when it does it is very nice. It will oxidize quite a bit over time and take on a deep chesnut colour. It also has small pits in the surface of the wood (in areas) which often have to be filled before sanding. Hi Sam, getting the ingot is the easy part, it is how you treat the ingot afterwards that is the tricky part. You have to be very precise with the temperature range that you forge in, and it is slow. That is one of the reasons not may people are selling ingots, athough as the information gets out there more of that may occurr. There are a few wootz making tutorials on primal fires. Tim.
  25. Thanks Don, I have put up a set of pictures on my web site showing the furnace that I use and most of the process. I have to take some more pics showing the ingredients to finish it off. http://www.buffaloriverforge.com/the%20forge.htm cheers, Tim.
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