-Dark Ages Pattern Welding-
An interrupted twist chevron billet in progress:
See also my plans for a Dark Ages Smelt where I plan to make a seax much like this one from rock to blade...
A billet approximately 1" x 1.5" x 12" has been welded together in 12 layers and drawn out into a .75" x .75" x 32" square rod which has been cut into two pieces approximately 18" each. (Although 12 layers is quite low by modern standards, 7-10 was far more common historically. The beauty of these patterns lies in their boldness and deceptive simplicity.) These were then forged round and twisted in alternate directions with the straight sections kept edge up. They will be forged square again so they may be welded together. It takes immeasurable care to keep these evenly twisted through all of these transformations and took about one entire day.
Welded together & squared away. You can sort of see the pattern:
The billet with the edge welded on and lightly etched. The piece will be drawn out to almost twice the current length of 18", which will emphasize the straight sections a bit more and make the twists just about 45 degrees to the blade. Adding the edge and forging to shape took another two days.
So here's the blade forged to shape... it must now be ground to the final shape starting with a 50 grit belt and working up to 400 grit. The grinding took about four hours on this piece but I was grinding slowly & carefully.
The next step is to heat treat the blade to make it hard & flexible. There are three ways to go about this: a differential heat treat which would leave the spine completely soft and allow for a very hard edge. The drawback is that the difference in the steel's hardness will show as a difference in the etch that brings out the pattern. Another method would be to heat treat the entire blade, including an even temper, etch the blade and then temper the spine further. This would create a soft spine although not as soft as a differential heat-treat. One further method, and indeed the method I have used on this piece is to temper the entire blade somewhat springy. This means the edge is not as hard as possible, but that can actually have advantages such as easier field sharpening. It means the blade is not going to bend in the heat of battle as it might with a differential heat treat nor is it likely to break. No one solution is absolutely better here; and actually, most Migration / Viking blades were made up of a composite core / spine of low-carbon phosphorus-differentiated steel and a high-carbon steel edge. The low-carbon material did not harden and thus, would provide some protection from breaking. Or so they say.
I heat treat in my digitally controlled salt tanks, so I do not have to worry about cleaning off another layer of scale. I simply insert the blade into the molten salt at exactly 1475 F and quench in Heatbath #50 quenching oil at exactly 150 F. The blade is now as hard as possible and could break if I looked at it wrong. I tempered this one thrice at 460 F to bring it from brittle to just under springy. Here is how it looks after heat treating and a light etch in some ferric chloride:
And finished with Sterling, fossil walrus ivory & a Finnish spectralite set in the pommel...
-Click here for a close-up-