Wednesday, February 13, 2013

Why I Use Wrought Iron: Materials Asking Questions

My early April return to the United States was somewhat unexpected.  I'd planned on finding a Volunteers For Peace program on an archaeological site elsewhere in Europe. My month at Owen's working continuously in a shop, exploring myself through creativity and my world through materials and tools, pulled me into something that I didn't want to break up by un-grounding myself again.  So, instead of continuing my travels, I decided to return to Oakland to the familiar shop of Jim Austin and Jeff Pringle, and to bring my new experience to the test and further exploration.

One of the ways I decided to do this was to introduce techniques I'd begun with Owen, using new materials.  Owen tends to buy lots of high-quality, modern, commercially-produced Bessemer steel for its predictability in working and heat-treatment, reduction of risk variables, and general superiority.  He personalizes it by pattern-welding and doing his own heat-treating.  Just because he prefers to use those as a craftsman and a businessman, his creativity and curiosity as an artist and a scholar have led him to the use of and experimentation with many older and homebrew steels and irons; wrought iron, bloomery iron and steel, shear and blister steel, tamahagane, wootz crucible steel, etc.  These older forms of ferrous metallurgy interest me immensely, and Jim and Jeff have quite a lot of experience in these, so I jumped in with enthusiasm. 

The above picture is the first piece of wrought iron I ever worked with, a very popular material among the bladesmiths of our movement for its textural expressiveness due to a varyingly visible grain-pattern.  The grain of wrought iron is a product of its very particular smelting process, which leaves an amount of silica slag in the metal left over from the original ore, which was not refined out during the process.  I love its texture, always having been moved by the natural grain of wood, but in something so seemingly immovable as iron, it's more mysterious somehow. 

The wrought iron I was using here was part of a large Victorian-era bridge that Jim and Jeff found in the Mojave desert.  I'm fascinated by the use of found objects and materials, because of the inherent story they evoke.  Sure, any material has a source or origin, and many of them are impressive and interesting if you understand them, but first the question must be asked.  Often, a homogenous commercial steel like 1095 does not necessarily invite a question as to its creation.  Every batch of wrought iron that was ever produced is different, and it has a characteristic of visible grain that encourages you to ask what the grain is, why it's there.  That question, that curiosity, is the seed of the imagination that allows you a story, gives a prior character to the object, because it had a life before it met you. 

That's why I use wrought iron.  Historically, it was forge-welded to pieces of higher-carbon steel to give mass to a blade while conserving higher carbon material for the edges of blades.  Wrought iron has a carbon content around 0.1% - 0.3%, meaning a few things.  It won't harden (meaning there is not sufficient carbon to for the crystal matrix necessary for that) and probably won't ever snap, but also can't temper, so it's very prone to bending.  With this in mind, you can decide on your ratio of steel to iron in a blade and what's important: cutting ability, mass, conservation of material, and visual effect.

I used it here in a blade construction generally called san mai, what I believe is a Japanese term for an originally Chinese technique, but which understandably originated independently wherever there was ironwork.  It's produced by sandwiching high-carbon steel between two other steels or irons, and removing material on the bevels to reveal the high carbon on the edge.  It's the first forge-welding I did with Owen, but the above billet is one I welded in Jim Austin's coke forge.  That billet yielded a few blades, like this double-edged one below:

I forged too much on one bevel before grinding and pushed the wrought iron onto the edge, which is an unfortunate occurrence. That was less of a problem in the below little broken-back sax, with which I was pleased with my ability to forge to a shape I designed.  I'm discovering that with practice comes control, and since there's no limit to imagination, the only limit to realizing it is practice.  So go get on that project! 

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