MattBower

I know we're getting pretty far off topic, but . . . http://asmcommunity.asminternational.org/static/Static%20Files/IP/Magazine/AMP/V167/I02/amp16702p24.pdf?authtoken=cb31535fc425fd4bcb22e182921e2963ed861895 Of course it's true that metals don't diffuse nearly as rapidly as carbon, but I'm not aware that the component steels in ancient pattern welding often varied significantly in terms of alloying elements other than carbon. I'm willing to be enlightened, though.

Notice that I said, "largely myth, particularly with respect to ancient steels that were composed almost solely of iron, carbon and impurities." Modern alloy steels may be a slightly different story (although selecting steels with significantly different properties can cause its own set of problems), but my main point was that in a world where even carbon content was somewhat hit-or-miss, and other alloying elements were there in very small amounts and largely by chance, the "best properties of two different steels" idea is nonsense.

Just to be clear, I know of no evidence whatsoever that there was any pattern welded aspect to genuine wootz/pulad/"Damascus" blades. I don't think you believe there was, but it's not completely clear from your description. (The word "lamination" usually implies taking two different materials and joining them in a solid state process, like plywood or modern pattern welding.) The papers I've read by Feuerbach, Verhoeven & Pendray, and others conclude that wootz was a crucible-melted monosteel, and the pattern was a the result of carbide banding having to do with the hypereutectoid nature of the steel, plus some combination of thermal cycling and the natural presence of carbide formers such as vanadium. E.g., Home Page The Key Role of Impurities in Ancient Damascus Steel Blades TinyURL.com - shorten that long URL into a tiny URL TinyURL.com - shorten that long URL into a tiny URL TinyURL.com - shorten that long URL into a tiny URL "Segregation," rather than "lamination," would best describe what was going on in these steels. And the carbides in the carbide bands would've produced the microscopic sawtooth effect you're talking about, no lamination required. The guys who're making this stuff today don't seem to have any problems letting it cool before they work it, although it needs to be worked in the right way and at the right temperature. The idea that pattern welded steel allows one to take advantage of the properties of two types of steel is largely myth, particularly with respect to ancient steels that were composed almost solely of iron, carbon and impurities. Any serious degree of folding and welding quickly homogenizes the carbon content unless there's a barrier such as pure nickel between the layers -- and in ancient steels there wasn't. That may not be the case for san mai construction and other types where the layers are coarse and the welding minimal, but for typical layer counts in the hundreds it's certainly true.

Buy a crucible! Clay & Graphite Crucibles The homemade alternatives that are going to occur to you really aren't safe.

Nobody's going to shut down coal mining in this country anytime soon. The entire economy would completely collapse. We can't suddenly just do without half our energy overnight. There's plenty I don't like about this current administration, but Obama is neither stupid nor crazy, and neither are (most of) the folks in Congress. Not gonna happen.

I've heard lots of methods of heating metal for beating, but this isn't one of them. I take that as a bad sign. But not having tried it myself, I really can't say for sure. You should definitely give it a whirl, though (don't electrocute yourself!), and if you're interested in knifemaking I'd say you should certainly hold onto it for heat treating!

Except induction heating, which is about as efficient as you can get. :)

That'll be good for heat treating, but I don't think you'll find it satisfactory as a source of heat for forging. It's going to heat the steel primarily through radiant heat and a little convection. That'll be a very slow process compared to any common heat source for forging, such as solid fuel, gas or oil. (Or induction. Man, I'd love an induction forge! But that's a little OT.)

What sort of steel are you using, and exactly how did you anneal it?

For a guy with a million questions, you sure seem to have all the answers.

The steel that comes out of a Japanese tatara smelter is very heterogeneous; some parts will be very low carbon, and others will be nearly cast iron. The bloom is forged down flat and broken into pieces, then sorted by carbon content (mainly based on a highly trained eyeball). The pieces are stacked together (I imagine the process of selecting the right pieces involves a lot of experience, too) and forge welded into a solid mass, then forged out into a billet and repeatedly folded and welded. (But not 200 times!) That homogenizes the carbon content and, as Steve said, helps work out impurities. The result is hardly super-steel. Closer to 1050 without the manganese.

I don't think I've ever seen anyone give such a detailed account of the provenance of their furnace shell before. Here's a basic how-to: "2 bucks" crucible furnace (Skip the Portland cement that he mentions. It won't do anything good in the mix. It breaks down at aluminum melting temps and fluxes the other ingredients.) For your refractory, Rutlands Fire Cement from the hardware store mixed with perlite (1:4 cement : perlite) will be OK for aluminum, though it won't be terribly durable. You can add a little water if necessary, but don't make it too wet; you don't want to pour it as much as ram it. Beyond aluminum things start to get a little more complicated. But don't worry about making your first furnace perfect. If the bug takes you'll end up building several anyway.

The potters have lots of good stuff. Ceramic blanket, soft firebricks, anhydrous borax, fluorspar if you want an even more aggressive flux than borax, iron oxide if you want to try homebrewing iron and steel, grogs and clays if you're interested in homemade refractories and/or making crucibles, etc. I have an idea -- I haven't done the research -- that potters were probably the first iron smelters, albeit accidentally. Which, if true, sorta makes 'em our direct ancestors. Anyway, yes, always keep pottery suppliers in mind when you're looking for some of the harder-to-find stuff.

The vast majority of blacksmithing through the ages used trees as fuel. They're more than adequate. But it's a lot more pleasant if you convert them to charcoal before you start forging.

All I'll say about the lead question is that once it's in your body it essentially remains there forever, and it's much more dangerous for little ones than for adults. Stunted growth, permanent neurolgical damage, all kinds of nasty stuff. Even if a single forging session delivers only a small dose, the dosage is cumulative. And realize that even if you're not working at home, your kids can be exposed to lead dust on your clothes and body. Just be careful. As for identifying scrap, it's a combination of education and guesswork. There's no guarantee that it's safe to work with. (Some of the copper alloys contain especially nasty stuff, which is why you should be extra careful with brasses and bronzes.)

Hallelujah and amen.

Pottery Supplies Those folks have a Brisbane location. Their catalog lists "fibre" blanket (too bad they can't spell -- just kidding, of course!) and refractory bricks, both hard and insulating. They also have refractory cements including a Kaowool hardener, which will serve in the place of ITC if you can't get it. (I don't think it'll give you the same efficiency boost as ITC-100, but at least it should seal in the unhealthy fibers.)

Take a picture of your forge and post it, please. Charcoal is fully capable of melting or burning steel. I have trouble understanding how you can have a charcoal forge that "does not run very hot." The only thing that springs immediately to mind is that perhaps you're using way too much air. You can actually blow the heat out of the fire that way.

As a good rule of thumb, insulation is light and fluffy. (Think fiberglass insulation like you see at the home improvement stores. Light and fluffy, right?) Conversely, and also as a good rule of thumb, things that are dense and not-fluffy usually aren't very good insulators. Clay and sand/adobe/whatever you want to call it is dense and not-fluffy. Draw your own conlcusions. But for a solid fuel forge made of metal you really don't need insulation. If the forge is made of wood you need a little insulation, but it doesn't have to be very good insulation. It's not there to make the forge thermally efficient. If you want to make your clay-sand mix more insulating, you can add some perlite or vermiculite. (Perlite and vermiculite are light and fluffy. They will make your clay-sand mix lighter and fluffier.) But for the sort of forge you're making there's really no point.

Was that quote in Zimbabwean dollars? Sorry, I couldn't resist. Unless your anvil has some truly extraordinary feature that makes it exceptionally valuable as a collector's item, rather than as a tool, that price range is nowhere near realistic.

Can you purchase the blowers separately? And if so, how much do they cost? What is your blower made of?

What's the story with that hand-cranked blower, Joe? It looks brand new.

I think that's actually me you're quoting there, Thomas. At least the 1040(ish)-1060(ish) range is what I was given when I contacted one of the two major American rail anchor manufacturers (UNIT) a while back, and I posted it on AnvilFire and perhaps elsewhere. (I think I remember you saying something about how it'd be nice to be able to identify the ones that are 1060ish.) But getting hard numbers on chemistry always beats taking someone else's word. I was told those hammer bits were S5 . . .

jimbob, No, he did it as a favor. I anticipated before I posted these results that I might get some requests from other smiths wanting to have certain items analyzed. Perfectly understandable. But I haven't decided quite how to handle those sorts of requests. I want to help out, but I also don't want to wear out my welcome by asking too much. Let me think about that.

I posted a thread in the main blacksmithing forum that's probably going to be of interest to some of the bladesmiths as well. I don't know what the etiquette is here as far as posting the same thread in multiple forums, but here's a link: http://www.iforgeiron.com/forum/f7/chemistry-scrapmongers-10796/