The wider profile of the mountain style kotanto is inspired by a kamakura sword and has a more deeply curved tip (fukura-tsuku) and shorter drop point. The simple and humble mounting style is inspired by the age-old style of farming and foresting tools traditionally used in managing satoyama lands.
Satoyama are the managed forest areas that border the cultivated fields and the mountain wilds in Japan. Historically they provided soil nutrients, firewood, edible plants, mushrooms, fish, and game, and supported local industries such as farming, timber construction, and charcoal making. The interaction of forest, arable land, wetlands, and streams are an important component of the satoyama landscape.
The raw material for this blade comes from a reclaimed harrow tooth salvaged from a farm in northern Alberta. Shown after the forging stage, all shaping done by hand hammering.
After hand filing to define the machi (tang notches) and clean up the profile.
Yaki-Ire: Hardening the Blade
After hardening the blade with a traditional clay and water method. The thicker clay layer on the body of the blade insulates the steel, causing it to cool slower and form pearlite/ferrite. The thin slip layer on the edge increases the surface area, causing it to cool very quickly, forming martensite.
The bevel is ground down until almost sharp, and the blade surface is cleaned with hot vinegar water to remove remaining forge scale.
This particular harrow tooth seems to have been made of an old piece of shear steel, a rare form of pre-industrial steel used up until about a century and a half ago.
The characteristic layers of a shear steel hada can be seen along the edge where the waterstones have polished the bevel.
Tsuba: Making the Guard
One fourth of a silver-plated copper bus bar bracket is forged to shape. The round hole in the center is reshaped and drifted to create the nakago-ana shaped opening for the tang.
Hand filing adjusts the fit snugly to the shoulders of the blade.
The rim of the guard is filed to an oval profile and given a hammered finish.
The inside of the handle is carved to fit the tang snugly, then the halves are joined together with rice paste glue. When dry the shape of the guard is used to create a shape and the handle is carved to match.
As with the handle, the scabbard is carved to fit the blade with saya-nomi (鞘鑿, scabbard chisel) and then joined before shaping with kiridashi (carving knife), and kanna (hand plane). A kurikata (cord loop) is carved from Maple and wedged into a keyway.
The first layer of natural urushi lacquer is wiped off leaving a thin sealing layer in the pores of the wood.
When fully cured, the handle is wrapped tightly in natural cotton cord to provide strength and grip texture.
The scabbard is also strengthened at key points with tightly wrapped cord.
The cord is saturated with natural urushi lacquer and allowed to cure for several days. Several additional coats of urushi are used to create the final surface, each requiring several days to cure.
Reclaimed tea powder is used to give the scabbard a sabi-nuri (rust texture) style ishimeji stone texture. Multiple layers of urushi are used to seal, saturate, and create the final surface appearance.
The handle is polished with dried tokusa (horsetail) and then sealed with a final layer of fukiurushi.
Carving and fitting the mekugi (bamboo peg) that will hold the entire assembly together.
When all of the components are complete, the blade is given its final honing and the knife is ready for assembly.
Specifications
The blade is just under 5.75″ long and the overall length is about 10.25″. The spine at the munemachi is about 5mm thick.
Katachi (geometry): hira-zukuri, kaku-mune
Hamon (edge pattern): suguha
Boshi (tip pattern): maru
Nakago (tang): futsu, kuri-jiri, one mekugi-ana, signed near the tip
Mei (signature): hot stamped katabami-ken kamon
Koshirae (mounting): satoyama hamidashi style, issaku
