Monday, March 2, 2015

A Wrought Iron Witch Broom

When I first took up blacksmithing wrought iron scrap was plentiful.  Many people were bringing old iron to the local scrapyard and getting cash in return.  Farms in the outlying areas had an abundance of iron implements in various states of deterioration.  At the scrapyard the collection was being cut up into manageable size pieces for loading in the trucks which transported it to larger steel recycling centers.

The scrap yard I frequented was a two-man operation.  I got to know both of them pretty well.  I could come and go as I pleased and we had a casual relationship in which I took what I wanted and gave all my scrap to them.  Usually no money changed hands.

I picked up quite a bit of old wrought iron from wagon tires and other agricultural machinery. And, on the other end of the spectrum, I picked up a lot of harrow tine, hay rake and spring stock in the tool steel category.

As it turned out I still have most of that stock.  I found that a little tool steel goes a long way and I almost never forged the old wrought iron.

On the few occasions when I worked with the wrought iron I learned the necessity of forging at a high heat.  That lesson was probably worth all the collecting.  If the wrought iron is worked to cold it delaminates and forms what I call a mop or, more colorfully, a witches broom.  The end of the bar sort of unravels and goes in all directions.  This can be corrected by forge welding if the smith has the skill.

I believe this behavior of wrought iron is well known to anyone with some experience but I was unable to find documentation of it on the web with the exception of this link.

I’m fascinated by these details which at one time must have been common knowledge and yet have left little evidence in the technical records.

The stereotypical witch broom was a birch broom or a broom made from similar fiber.

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