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Doug Ayen
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Doug Ayen

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How do you measure the brightness of a polished metal surface?

During a recent knifemaker symposium, the topic of stainless damascus came up with the stated problem that nobody really knows which high carbon stainless steels (HCSS) have the greatest contrast. In fact, the expert said in his opinion it was just easier to mix in either non-stainless (D2, L6) or non-high-carbon stainless (305, 315, 420, etc) and accept the inconsistency in the final product. What I would like to do is take a sample of each common HCSS (ats34, bg42, 440c, sv30v, etc), say 20mmx20mm, heat treat, polish to a standard grit, probably .5 micron(A5, 1500 grit ANSI) and then measure the brightness, or reflectivity of the surface, then etch with some standard etchants and see what that shows.  The problem is, I'm not sure what to use to do the measurement. Back when I did typesetting, we used a reflectance densitometer to do something similar, but I'm not finding the right tool. Any suggestions? Ideally, what I'd want is a calibrated light source aimed to reflect off the surface at a specific angle and hit a photoreceiver that can measure how much of that light is being received. The comparative numbers should give a better idea of what existing HCSS would have the highest contrasts, and given the metalurgical analysis of the respective steels, might suggest alloy formulations to try for an even higher contrast. Just don't know what the tool would be to do that measurement.
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This is rapidly turning into "Papers Please: the NIST/ISO Expansion Set"....
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Doug Ayen

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Years ago, I made a seax blade from homemade iron and steel, but never could find a handle style I liked. After studying an article on the geometric proportions of medieval swords, I decided to try my hand at it, not really feeling like going out to the forge today. Instead, I spent a few hours designing according to the same proportions as many early pattern welded swords. The next time someone asks me how hard can it be to design a knife, I think I'll show them this effort. The blade and handle material (mammoth molar) are the images at the top. All the thin lines are different reference geometrical shapes. I think I like this one. What do you think?
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"Righteousness is Quadrangular" A Hypothesis of Geometrical Proportions of Medieval Swords by Peter Johnsson, if anyone is interested. Fascinating stuff.
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Doug Ayen

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Some photos of a knife I'm working on. Wrought iron body, high carbon steel edge. This shows the process from raw materials to the as-forged state, all ready for final grinding and heat treatment.
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So where'd you find the kryptonite?  ;)
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Doug Ayen

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Tomorrow (Nov. 4) I turn 45. Anyone interested in getting together for dinner somewhere? I'm open to suggestions.
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Oh, wait I missed that date completely.  I read this on the wrong day and thought, "I'll say happy birthday on the right day!" and flubbed it. Happy belated birthday anyway!

A Very Merry Unbirthday to You! (yes, you)
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Doug Ayen

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Shop time, with some pics of works in progress. 
http://blackanvil.livejournal.com/127205.html
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Sulfur, phosphorus, and other contaminants are always a potential issue, but the process for making cast iron has pretty much had that worked out for the last couple hundred years. Still, this is why I bought some old cast iron, instead of modern stuff, for the experiments.
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Doug Ayen

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I'm about ready to start my next batch of blister steel. I use a metal retort in which I place hammered thin pieces of wrought iron, this batch a mix of 130 year old old bridge trusses, colonial era safe armor, some heavy (2" thick) wrought iron chain from the 19th century, and some old wrought iron nails of unknown provenance.

I made a larger retort to replace the one I melted last year, black iron pipe with one end welded closed except for the mandatory (MANDATORY!!!1!one!)  weep hole, and the other closed with a cap lubed  with nuclear grade high temperature nickel anti-seize. After a few days in the wood stove, getting that cap off is painful.

To turn the wrought iron into blister steel I'll pack the wrought iron with a mix of powdered wood charcoal, bone charcoal, and this year I thinking about adding a phosphorus source to the mix. Lay in the wood stove, build fire, let soak until a sample piece, when hardened, breaks cleanly and shows a good grain structure. If a cross section polish and acid etch shows an even shine, you're good to go. This usually takes me with my setup about 48 hours, usually broken up into multiple sessions as I only run my wood stove occasionally.

I'm thinking of adding the phosphorus because metallurgical analysis of ancient blades shows that the hardening and embrittlement agent in their steel was as often phosphorus or other materials nowadays considered contaminants as it was carbon. This was true from the start of the iron age until the 17th century, when ferrous metallurgy really got its start. It’s not too surprising — pretty much any element in the same area as carbon can be used to harden steel — nitrogen, boron, silicon, even aluminum are used as hardening agents in modern steel, and phosphorus is right next to them in the periodic table.

I'm thinking this would probably result in steel of a different shade when etched, and that would add additional contrast in pattern welded blades. It wonder if some of the effects seen in migration era pattern welded blades mentioned in the sagas and surviving literature were created by the deliberate use of steels with different carburizing agents or accidental (but convenient) contaminants.

The first thing that comes to mind for an easily accessible and cheap source of phosphorus would be matchbooks (there’s phosphorus in the strike strips, not in the match itself, except for strike anywhere matches), but mom said never to play with matches -- any other ideas? I'd prefer to avoid mail order.
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Let me know when you plan on doing this I'd love to help 😁
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Pics of swords and rapiers up on LJ, along with some commentary.

http://blackanvil.livejournal.com/130899.html
I was up in NYC last weekend, I went to the Met's arms and armor gallery, took a good look at some swords and got some good pics as research for some projects. First up, I have some ideas on making a version of Stephen Brust's Godslayer in rapier form. I saw in a book a few years ago a…
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I braved the cold, unheated shop (temperature: 16F) and put in a couple of hours of grinding on the cleaver after work. I did the profiling, beveling, and shaped the tang. I finally gave up for the evening when frozen fingers (despite the searing heat grinding generates, enough that, as you can see on the tang, it hits "blue" temps ~540F) made control difficult and grinding dangerous. Also, I need to adjust the rotary platen on the grinder, and my fingers were sticking to the metal, the wrench, the cleaver . . .  

The body is 270-year-old colonial-era wrought iron from an old safe, not a very high quality of wrought iron, so there's lots of flaws and imperfections in the body, which are those little squiggles and dark spots on the blade. That said, I'm really liking the pattern that's starting to come out with grinding. I forged thick and ground thin, so there should be lots of figuring in the body when I've got it polished and etched.
Pics:
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Your work is wonderful. 
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Another phone interview conducted this morning, I hope one of these pans out soon.
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Indeed.
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Doug Ayen

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The word from the hospital is that mom's surgery went well. She'll be in the neural ICU overnight, and in the hospital until at least Monday.
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My mom will be undergoing major spinal surgery tomorrow afternoon. Please keep her in your thoughts.
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Hugs. May it go well and may she have complete recovery. 
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Doug Ayen

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Odd question of the day: "What does a Packet Buffer smell like?"
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Styrofoam. Keeps them from getting damaged during transport.. 
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