Exhibition of Japanese arms of Polish private collections and District Museum in Torun - 2011
Tatara project - Biskupin 2008
In 2008, the Archaeological Fest Biskupin, under the theme "Japan - a country not only the samurai," we conducted an experimental process of melting steel in a Japanese furnace - Tatara. Due to the budget, we could not build a Tartar original size (about 3m x 1,8m x1,2m ) and we had to limit ourselves to a smaller version. Our furnace Ttatara was 1.2 m length of 0.9 m in width and height of 1.2 m.
For the construction we started in August and a week working on the underground part of the furnace, which is a very important part of the whole structure Tatara. This underground structure was designed to reduce heat loss in the ground oven. Its function can be compared to a thermo-battery.
At the very bottom of the drainage ditch dug. Chamber built over it, which filled the timber and then fired with a small air-so that was charcoal. Charcoal in the chamber (which is directly under the furnace proper) served as a kind of battery pack heat. The chamber was surrounded by an additional air channel (double-walled thermos).
In August, we completed work on the part of the underground and overground part stove built. In the meantime, we have iron ore, which is then gathered in containers. We hid it in a dry room where she waited for the September melting.
Tatara already finish the construction during the Archaeological Fest. After three days of construction and drying, we ignite our Tatara. The process ran continuously for about 72 hours.
After burning the excess of charcoal in the end, to the delight of the visitors we pitched our Tatara furnace. With a broken furnace extracted the huge lump of "Kera".
She had an impressive weight over 100 kg and still it was heated to redness. The next day we started to break Kera into smaller pieces. From this block we obtained approximately 40 kg high-grade "Tamahagane" (1.1 -1.2% C) accounted for the rest of the steel of medium carbon saturation, soft iron and pig iron.
Tatara process was a success!! During this experiment we used about 400 kg of iron ore, and about 1000 kg of charcoal.
