Today was a good day. I spent about 3 hours on the forge. My arm did much better today than it did on Sunday. Anyway, after doing some yard work, I decided to fire up the forge. I spent the first hour doing some more work on the bootscrapers. While I was working, my mind kept coming back to a show I had seen on the History or Discovery.
The show was talking about cannons through the middle ages. The earlier cannons were interesting but a cannon from the later middle ages interested me more. The cannon in question was one from the Mary Rose(a later middle ages English warship). www.maryrose.org
Now, I have a soft spot for the Mary Rose. I've visited the Mary Rose museum in Portsmouth 3 times in my life. There is something about that ship which has always interested me. Anyway, the show was talking about the cannons recovered from the Mary Rose.
The show detailed the reconstruction of one of these cannons. The cannon comes from an extremely complex construction process. It starts with long iron staves layed side by side to form a cylinder. Very similar to how you make a wine barrel. Once the cylinder is formed from the staves, you need someway to hold them together just like the metal bands on a wine barrel. The way this is done on the cannon is by forming metal rings very similar to the rings you wear on a finger except on a much larger scale. These rings are heated, placed over the cylinder, then cooled. During the cooling process, the rings shrink forming a tight band around the staves holding them tight together. From what I could tell, these rings were down the hold length of the barrel.
Anyway, during the show, they showed the blacksmiths making the gun. The part that caught my attention the most was the forming of the rings. The smith was using a bending bar to form the rings. A bending bar is like a long two prong fork with the tines pointing out to the side. It is placed over a hot bar and the leverage of the handle makes it easy to bend the bar.
When I had tried to form circles in the past, I had always done it by hammering the metal over the edge of the anvil's horn. While this worked it has several drawbacks(especially to a new smith like me.) It tends to create bulges on the edge of the metal where it is struck and it is difficult to make that near perfect circle.
So, today I decided to make a bending bar and give it a try on my metal. Now, this idea had occurred to me before I saw the show but I had assumed that the metal was too thick to bend this way. Well I made the bending bar, heated up some 1 1/4" x 3/8" bar stock, put it in the vice and bent it...
Damn, it was so easy and so easy to control compared to the hammering. One of the most common misconceptions by non blacksmiths is that blacksmithing is almost all hammering. In reality, only about 25-50% of blacksmithing time is hammering at the anvil.
This also reminded me of one my great weaknesses that I am trying to get rid of. I have a bad habit of forming theories on how things should be done even when my level of experience is not that great... Well, I proved myself wrong(I think). The bending bar will probably be the way that I will form the circles for the clock gears.
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