Math and blacksmithing

Explore! 2016

I was not the best math student.

It started early. I buckled down and memorized multiplication tables, but fractions were... difficult and confusing. I liked the puzzle of algebra at first, but keeping track of the decimal places and negative signs was like herding cats. I thought geometry was really cool, but I didn't have an intuitive sense for whether the answer made sense or not.  

By senior year of high school, I was being tutored by my teacher twice a week and my confidence in math was pretty dismal. I took calculus in college and the fact that I remember nothing about it leads me to suspect I've consciously blocked it out. (Stats were a bit different--more learning the concepts and knowing which buttons to press when--which was lucky because I had to take 3 stats classes.) 

And then I took up blacksmithing. 

I attended Blacksmith Days at the Blacksmith Guild of Central Maryland in 2010 where Mark Aspery was giving a demonstration on some complicated joinery that was the subject of his third book (buy the books). He was talking about the math necessary to get everything to fit correctly. 

I felt that old familiar tightness in the back of my throat.  Ah, my arch nemesis, we meet again! 

But Mark wasn't advocating for precision down to three decimal places; that's the realm of machinists.  Blacksmiths need to get close enough. Close enough so that it fits. Close enough to look right. Close enough so that you don't have to do a lot of extra work. 

"Okay", I thought. "I can do that.  Maybe."

In 2014, I took a class with Matt Jenkins at the John C Campbell Folk School and tried my hand at mortise and tenon joinery for the first time, making a garden trellis.  Making a tenon on one end of the bar is just a matter of using the tools correctly.  Getting the bar between two tenons to be a specific size doesn't happen by chance. I broke out Excel and programmed it to calculate the stock size I'd need to start with for each piece. A few weeks later, I gave a demonstration about the project at Central Virginia Blacksmith Guild and shared my experience. 

​That was the beginning. 

[You don't NEED math to do amazing things in metal.  It's just that math helps newbies skip over about 10-20 years of trial-and-error experience.]

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