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Peter T. Swarz-Burt

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  1. The top-center of a wootz invot tends to be more crumbly than the rest, which leads to difficulties in forging and larger than necessary material losses as the cracked material is removed. In the "donut" technique the ingot is flattened height wise into a disc, then hot-punched straight through the the center. This removes a substantial portion of the crumbly material, and once the donut is opened up it exposes the remaining cracks for easy removal. The result is easier forging, less material loss, and a more even degree of cross-sectional change throughout the length of the bar.
  2. This was a 13 pound ingot made using a couple things that are new to me. This was my second time using a clay-graphite crucible, and my first time using the "donut" forging technique described by Niko Hynninen. The final weight of the finish-forged bars was 11.5 pounds, so very little loss.
  3. Jan, I got started off on a tangent of forge and burner design versus the coatings experiment that you were originally discussing. To test the coatings I think you are right that a time-to-temp measurement would be sufficient. Someday I would love to see the forge liner debate of "thermal mass" versus "insulating value" finally resolved, but that will be another day. I barely have time to keep up with the things I actually have to do, let alone start working on things that I simply want to do.
  4. I think that your experiment will need to involve a few parameters: -forge temp that needs to be achieved and a thermocouple to measure it -forging temp that needs to be achieved, which I guess will need to be ascertained by eye -standard bar size to heat so others can repeat the experiment For each forge design, burner type, lining, and coating there will be a lower limit of propane consumption below which the forge simply won't reach the required temperature. Measuring the time-to-temp at various pressures (flow rates) would establish the initial down time, while the time to heat a specific bar to the required temp would establish the rate at which work could be achieved. The standard bar size could be a 4" length of 1" square welded onto a 1/2 RD handle. I think using three of these in the experiment would be appropriate. The basic procedure could be a start from dead-cold on the forge and bars. The timer is started when the fire is lit, and a note is made when the forge first reaches temp. The first bar is then added, and then the time is noted when that reaches temp and is removed and set aside. The second bar is then added, etc. The experiment ends when the third bar reaches the required temperature. The most accurate way to measure the gas consumption would probably be with a scale, assuming that you have an accurate scale for the size of tank you are using. Gas consumed/time elapsed would be the output of the experiment, and this could then be further compared with the amount of useful work that heating the three bars represents. The equivalent experiment with charcoal would be to weigh the charcoal before and after...though this would require some way to extinguish the fire that wouldn't damage the forge. In the case of some of the coatings, I think the experiment would need to be performed once when the coating has just been applied and then a second time after a week or two of reasonable use. My experience in the past has been that the coatings are very effective for a while and then the effect tapers off, I assume due to chemical reactions between the forge atmosphere and the coating material. If you are able to find a coating that is effective and cheap, then re-coating periodically would be no problem. The one time I tried ITC-100 I was very happy with the initial results, but then sorely disappointed by the cost over time as the coating degraded. My last few forges have just been Inswool painted with Kaolin slip, and that has worked quite well from an efficiency standpoint...but it doesn't hold up well to abuse. Adding Kyanite (mullite) to the slip should reduce the crazing of the surface, and adding Alumina should theoretically improve the IR reflectivity. EPK and Kyanite are both readily available and quite cheap. I'm not so sure about the alumina.
  5. Very cool! Interesting effect from the twisted jelly rolls!
  6. Thanks guys! It is a basic blade shape that I have done a bunch of times over the past 15 years, and I enjoy it every time. It hasn't ever become extremely popular, but I get an order for one periodically. Since everything is flat ground rather than hollow ground the "jelly-rolls" are less bold than I would have liked, but they do make for some interesting activity in the twist.
  7. Blade length: 14" Blade material: 15n20/1095/1018 jelly roll twist Handle material: carved moose antler This was a custom order based on the blades I made on Forged in Fire, the "Crusader Sword" episode.
  8. For charcoal, all I can say is that it is worth talking to a few suppliers/distributors and letting them know of your interest. When Jesus Hernandez was coming up to do a smelt at our Hammer-In last year we managed to pick up an enormous amount of good quality charcoal at $5/bag (20 pound bags), including shipping. The price was so low because the lump size on this particular batch didn't meet the standards the distributor wanted, but what did we care that the lumps ranged from 1" to 4" rather than being almost entirely 4"? This particular distributor sold the remaining 7 tons (!) to a farmer in Idaho who spread it on his fields as a source of carbon.
  9. I have found that the age of the forge lining is almost as important as the exact design when it comes to efficiency. We build all of our own forges and we tend to use them pretty hard, but I always notice a distinct decline in performance as the fresh insulation and coating begin to degrade. We go with 2" of Inswool with a thin coating of refractory over that for protection, and this heats up very quickly and gets very hot...until we bang something into it or poke a sword point through the lining by accident. Each round of repairs to the refractory shell improves matters a bit, but never back to the original performance. We run 100 pound tanks, and they last very different amounts of time depending on the type and amount of hot work getting done. Two of my partners were recently working on Viking-style pattern-welded swords, and all that forge-welding ran through an amazing amount of propane.
  10. Green glass rather than brown glass because green glass is colored with iron oxide while brown glass is not. I'm not sure what the pigment in brown glass is, but Wikipedia seems to indicate iron/sulfur compounds. Anything that you put in the slag could end up in the melt, so it is worth being selective. I have purchased Sorel Metal from Henry Perkins Company near Boston, MA. They do custom iron castings and this is one of their base ingredients. As a general heads up, Sorel Metal is VERY HARD and a bit of a bear to break up. I used Gray Cast Iron from MSC for many years, and it is very convenient because you can cut it with a bandsaw. You can also get Ductile Iron from McMaster-Carr. Ductile is generally of higher purity than Gray. I have not done enough melts with the Sorel Metal to be able to say how much of a difference it makes versus the Ductile Iron in a wootz ingot.
  11. Each color of glass is produced by adding metal oxides, and green glass is created with iron oxides. Brown glass is NOT produced with iron oxide, which means you are adding something else to your recipe that is not intended. Anything that is in the slag can also get into the iron, so it is good to be careful with your slag materials. Green glass is your best bet since it is a known entity.
  12. I guess the katar is kind of like a gun in that regard; practice may make you better, but "point this end at your enemy" pretty much gets you started. I tried the larger one out on 1/4" plywood and was surprised that it didn't try to roll my wrist much at all. Katars lack the hitting speed of swords but have far more stabbing power and leverage. I believe they were mostly used by un-armored men but they are often described as being "armor piercing". I would be curious to know more about their use but have never really seen any substantial descriptions beyond captions on pictures. Peter
  13. The handle is about 1" thick at the butt and in the palm swell with a little sweep in between and then tapers down into the blade. The blade itself starts at about 3/8" and tapers quickly to about 1/4" and then a slow taper to 3/16" in the flare. It is heavier than all but the two-handers, but then again it is also a lot shorter. A bit more like a kukri than a sword. As to being too heavy to use, well it is about the same weight as my standard forging hammer but the balance is much better. I wouldn't expect a lot of finesse from it in a fight, but it packs a lot of hitting power given how easy it is to swing. Once it is finished I'll try to get some video so folks can see it in action! Maybe we can rustle up a zombie (or a wooden stand-in) for the demo. Peter
  14. The wicked little forging bug has been having its way with me again, and that piece of 1.5" round 1045 just called out to become something dire and exciting. Thus the swax was born, and I can't decide whether it is of African or Malaysian parentage... possibly both? I haven't HT'd this yet, so we have only done some minor testing, but so far the feeling has been that it hits more like an axe than a sword. Even going into maple logs (strike point just behind the "bill") there is absolutely no feeling of impact. The fully integral handle adds a lot of weight, but it is super comfy and helps the balance a lot. I'm tempted to make some smaller versions as camp knives due to the serious tree trimming ability this would have. Overall length: 24" blade length: 18" point-to-point: 7" weight: 3 lbs 2 oz
  15. The title is pretty much self-explanatory. Having made the first katar I wanted to continue in the same vein, but it turns out that this a dangerous vein to pursue. It seems that things can't help but escalate, and I am a little concerned where we will go next. The blades are forged 5160 and the connectors are all forged mild steel. The blades are 8" long and the overall length is 21". I forged and ground the blades with triangular cross-section; nice and crisp center ridge on one side and a slightly convex "flat" on the other. The blades did warp ever so slightly towards the "flat", but I was expecting this and figured it would add a bit to the visciousness of the end product. I HT'd the blades before assembly and went for a wire wheel finish throughout. I think my next endeavor in this line will need to go back to a more traditional katar, but spice things up by making the blade in wootz. Peter
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