Saturday, February 28, 2015

Blooms - Blades - Historic Realities

I don't often make references over to Facebook.
The main reason why is that I actually find the format itself unwieldy and not at all suitable for any kind of serious discussion. (This not helped by the fact that Facebook increasingly will only function correctly with high speed connections and the latest software - and I have neither).

There is however, currently a very interesting discussion going on about 'what they knew' - in reference to bloomery iron smelting, modifying carbon contents and tool making. 
My own comments (below) come in something like 35th in the stream. There is some pretty good stuff there (even if in shorter bites), so go take a look if you can...
Hi, there's something I've been wondering.
Most Scandinavian literature debates why there's a tradition for laminated blades here. The conclusion is always part because steel was expensive.
At the same time the local archaeological consensus is that Scandinavians were unable to make steel other than by carburizing in a box up until quite recently (when crucible steel came), and that making steel in a bloom furnace is impossible.
Of course as Mark Green and others have shown, ...and I've tried myself, it is quite easy to carburize in a hearth.
So why should it be expensive? Could it be because while the low C outer layer could be rougher and less worked/refined, they insisted on heavily refined steel for the edge?
(my additions)
Hinted at by Tim Young and Lee Sauder : We do need to remember that in the distant past there was no 'scientific' understanding of process, no open sharing of information, extremely limited transportation. An individual was very much fixed to his local 'tradition' of working, only had locally available materials. Those of us who have experimented with differing furnace types and radically different ores (even different charcoals) know that there is a dance between furnace, ore, air and fuel. For those of us who first started the present 'Early Iron' movement, believe me, there were a huge number of complete failures before any kind of iron at all was ever produced. If we had kept working in isolation, with only our local resources, I dare say we would still be just making slag!
My first smelt attempt - L'Anse aux Meadows, 2001 (everything we did was WRONG!)

The objective of an ancient iron master was to make as much *usable* working bar as possible with the least amount of effort (labour, time, materials). The blacksmtith (much less the bladesmiith) was a totally separate profession. My understanding is that although higher carbon blooms might sometimes be produced, this was likely more on a firing by firing rate. It may be that one individual iron master in a certain spot might be more dependably able to make a specific quality of iron than others around. This could be the result of knowledge / experience / materials - or any combination of these factors (maybe even just dumb luck!).
Replica Currency Bars - for Parks Canada, 2001

I find there is often confusion between theoretical archaeologists and practical experimenters. Just because something can be demonstrated experimentally it is *possible* does not mean it was *common* (I think most of the experimenters here have produced cast iron by accident more than once for example!). On the reverse, all that can ever be said is our modern experiments only prove "A" way - we can never be certain we are demonstrating "The" way... 
Iron Smelt as Historic Re-creation - Vinland 2010

1 comment:

Unknown said...

Its obviously a minor quibble, but I would dispute the accuracy of the phrase "only had locally available materials". We have plenty of evidence that cultures of that time period traded with neighbouring tribes, who traded with neighbouring tribes, and so forth, resulting in materials being surprisingly widely distributed. The Vikings in particular would have had access, perhaps not in great quantities, to materials from significant distances.


February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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