Thursday, October 16, 2008
Kezuroukai in Yoita 1: tatara
Upon arrival in Nagoya a little after noon, I start helping Mr Sugimura and the copper smith Mr Kunia and son. They were still working on the Inu Jinja, and what a change since I have left 6 months ago.
This kezuroukai was held in Yoita, 与板町, a 5 hrs drive from Nagoya, my base station when I go to Japan. It is a little town of less than 8000 inhabitants, in Niigata prefecture. Yoita hosts several blacksmiths, some very famous in the Japanese woodworking community even abroad in Germany and the USA.
Highlights during this meeting was the tatara, the traditional method to reduce sand iron into steel (it is iron with a small but not negligeable amount of carbon). The tatara was set-up by some university students of the university of Nagaoka. The furnace burnt during 36 hours, and from 18kg of sand iron and more of charcoal, about 5kg of steel was harvested.
At the end of the demolition process (bricks of each layers are removed with a pick) the treasure iron is here, glowing at a more than 1000 degree Celsius. Demolition takes time, as one has to wait for the charcoal to burn until the level of the lower layer.
Though the process of making tamahagane, the precious material used to make high end tools and japanese swords, is the same, parameters involved are different: the heat has to be higher, and the amount of raw material much bigger. The time involved is also doubled. The yield of high grade tamahagane is much lower than the one of iron/steel or lower grade tamahagane.
Just wanted to post so you know that someone is out there reading. I enjoy your blog and encourage you to keep it up!
Do you have any pictures or other information about the sand iron used for this process?
I can be reached at: hinoki dot kuaimu at gmail dot com
remove the spaces and dot means .
I will post more on the latest kezuroukai meeting. I have seen the sand iron, but have no photo to show you. It does look like sand, with a rather coarse grain, brownish. It is wet before being poured in the tatara itself through its chimney.