Friday, April 30, 2010

Re-Inventing Layered Steels

This entry modified from a comment sent to the Norsefolk discussion group. Readers will see it reflects back to recent (and many past) articles on Layered Steels...

It is clear is that there is a huge amount of information available on the internet to anyone who searches for it on the topic of layered steel blades. Fairly quickly the critical eye spots those who actually know how to make the material themselves, or have done serious research, and the flakes and the phony.

One important 'historical' note:
The exact methods required to produce close replicas of Migration era Pattern Welded swords, or decorative patterned 'Damascus' blades, where essencially lost to the blacksmithing community (at least mostly in Europe and certainly in North America) through to the 1960's. Early work by a team out of the British Museum attempting to duplicate the amazing sword from Sutton Hoo suggested some possible methods (since proved NOT ideal). An American smith and blade maker named Bill Moran is largely responsible for re inventing working methods for producing effective layered steel billets and introducing those techniques to the North American bladesmith. When I started smithing in the late 1970's, only the top master bladesmiths knew how to make layered steels, and they were certainly not talking. The methods quickly escaped into the community at large. These days the first thing many new smiths attempt after learning how to forge weld is a layered steel billet. The published work of Scott Langton, who created the replica of the Sutton Hoo sword now on display at the British Museum, certainly needs to be mentioned.

There is a signficant termonology problem - one that has raised its head here already. I notice that the more experienced smiths and researchers here are using language in a quite specific way:
Layered steel - refers to creating a billet from a pile of plates, these plates are differing iron alloys. The billet may be drawn and folded a number of times to increase the layer count.
Pattern Welding - should be employed here in its strict archaeological definition. This is a method distinct to Northern Europe, at its height of use in the Migration period (say roughly 200 - 1000 AD). Here individual billets, usually of low layer count, are drawn to long bars. Bars are twisted in alternate directions. Then these bars are welded together to form the central core area of a blade. The result is a distinctive herring bone pattern.

Modern knifemakers (incorrectly) use the term Pattern Welding to describe 'any layered steel blade that shows a pattern'. Most typically the method they employ involves first creating a billet with high layer count. This block is then cut into or punched to expose the layers in predictable and regular patterns. What they are describing would be more accurately called 'Damascus' steel. This method is quite different than N European Pattern Welding, which believe me, is significantly more difficult than simple fold and stack.

see also :

I must disagree with comments that only etching will show the patterns. As the block is composed of differing alloys, each is effected at the polishing stage differently. There is in fact a subtle pattern revelled by the differing rates which the various hardness of metal layers are cut by the polishing. Generally holding the polished blade will suddenly show the pattern in the light. This may actually have been the case for historic blades. Statements in old tales like 'a serpent was seen to dance along the blade' describe this very real effect.
Truth is, we will never know just what finish was used historically on Pattern Welded blades. Modern blade makers use acid solutions to selectively etch and also stain the various layers. None of these acids were known during the Migration era. It is true that deliberate surface rusting, or discolouring with natural acids like vinegar, will increase the contrast in the alloys. This is a more subtle effect than use of solutions like Ferric Chloride or Nitric / Hydrocloric acids (all standard for modern blade makers).

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

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