TLDW #24 – Making an Ireko (nesting) Saya

An ireko saya (入れ子鞘, nesting scabbard) is a lining inside the saya which protects the blade from the hardwood. Furusato (故郷) means home place or hometown and contains the ideas of being rooted or grounded wherever one may sojourn, and a confidence and longing for return. This tanto has a simple and elegant form with a natural and humble mounting that reflects the rustic satoyama lifestyle and suits the aesthetics of the way of tea. more about this project

Inome Tanto

The inome (pronounced “ee-no-may”, 猪の目, eye of the boar) name comes from the pierced heart-shape designs of the decorative o-seppa (washers) on either side of the tsuba (handguard). This lovely motif is ubiquitous in Japan, seen often in architecture, furniture, and sword… Continue reading

Making a Bamboo Scoop for Water Forging

Simple technology for pouring water on the anvil, takeno mizusashi (竹の水差し) made from a piece of bamboo.

Forging with a thin film of water on the anvil and hammer prevents forge scale or oxide from being hammered into the surface of the steel. The hot steel instantly vaporizes the water and the resulting steam explosion blows the scale off of the work, keeping it clean as it is worked. This type of bamboo scoop is a traditional style tool for evenly applying water to the surface of the anvil or the hot steel. Read more about the process of making one.

Differential Hardening Sunnobi Tanto

Sunnobi tanto are larger than ordinary tanto (nagasa above 1 shaku) and may have sori similar to ko-wakizashi. Read more about the process of yaki-ire.

1. Using approximately a 1:1:1 mixture of natural clay, polishing stone powder and ground charcoal to mask the back of a hand forged blade about 1-1.5mm thick to slow down the cooling rate.
2. Brushing on a thin slip layer with extra charcoal added along the exposed edge to speed up the cooling rate and protect from carbon loss.
3. Carefully heating in a charcoal forge supplied by air from a fuigo box bellows until the edge reaches critical temperature.
4. Plunging edge-first into cold rainwater to cool the blade quickly and harden the edge while leaving the rest tough and resilient.
5. Testing for successful hardening with a file and then removing the clay with a mild steel scraper.
6. Slightly reheating the blade over the flames to temper the edge.
7. Test polishing on a coarse Japanese waterstone to check the hamon.