Friday, April 21, 2006

Some 'Bloom to Bar' Links

So - Karen tells me I should get with it and figure out how to add links inside these posts:

I had asked on EARLY IRON a number of weeks ago if there was a known sequence traditional to Northern Europe for converting blooms to bars. Like many things - its turning out that this is something that has never been researched (or the research is hard to find). James Brothers had bounced the question up to ARCH METALS. One response came back - indicating this link

If you check it, you will see that it does not really answer the question.

A bloom as extracted from a the smelter, is inconsistent in its structure. A 'good workable bloom' will tend to be denser in its centre, and have more slag inclusions towards the outside. Imagine a muffin with nuts in it. As the bloom is compacted, the slag (the nuts) is compressed and tends to squirt out of the material. Most of the force is applied from one direction - this will leave thin flattened ovals of slag. The smith will attempt to compress out as much of this slag as possible.
As you might guess - the direction of these thin (microscopic) slag inclusions would indicate how the bloom would have been folded and compressed.

I may get around to writing up something about this. In theory a metal artifact could be sliced and polished and examined in detail to determine things like:
How many folds were made
What direction the folds were taken
What exact sequence of folds and direction of flattening were used.

Right now I have been working in a method suggested by Mike McCarthy. That is taking the roughly lens shaped bloom and compacting primarily from 'top' , with hammering force at 90 degrees to the thinnest dimension. This is then folded in half and welded to create a 'book' (will be longer than it is wide). This is then pulled out to a long rectangular bar and folded back on to itself. This second weld is at 90 degrees to the plain of the first weld.


Since I'm adding links:

is the new information I'm adding to the main web site related to iron smelting. At this point the stuff has a simple list of individual articles and notes.


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