Yamagata Metal Casting
Yamagata Metal Casting
Despite being made of metal, pieces of Yamagata metal casting seem to have a warmth and sense of life, not usually associated with an inert object. This may have something to do with the fact that all of the more than 60 stages of the production process involve techniques fostered by years of tradition in the hands of countless craftsmen.
Stage 1
Creating the Mold Pattern: First, the design of the urn is drawn and from this drawing, the pattern with which to shape the mold is made. The pattern is fixed to a round frame in order to make the two halfs (upper and lower) of the mold. Then, to make the mold, the pattern is rotated and the sand packed down hard.
Stage 2
Decoration: Some Yamagata sand, which is said to be so suited to this work, and some clay are then used to produce a thin membrane in the mold and to create the exact shape required. A number of layers of this sand and clay mixture are applied to produce the mold. Next, the lugs for the handles are made and embedded in the mold. Then, using a spatula, a pattern of raised spots or other design is added to the mold. Needless to say, this work requires great concentration.
Stage 3
Core, Firing, Mold Assembly: Made from hard packed sand, the core is formed. This provides the void within the urn. When finished, it is allowed to dry naturally and then fired. The core is then placed between the upper and lower halfs of the mold, which is now ready for the casting.
Stage 4
Casting: Having removed any extraneous matter, the molten metal at a temperature of between 1,300°C and 1,500°C is poured without stopping into the mold. This is a moment of great tension even for the most experienced of craftsmen as it will determine the quality of the final casting.
Stage 5
Breaking the Mold, Finishing: When the casting has cooled a little, the outer frame of the mold is removed and then, using a small hammer, the core is gently broken up and removed. Effectively speaking, the sand has been biscuit fired and produced an oxidized membrane, which will prevent rusting. Any flashing or other unwanted pieces are filed away to perfect the shape and the surface is polished.
Stage 6
Coloring: To finish the urn, a special brush is first used to apply an undercoat of natural lacquer, which is then burned on to prevent it chipping. Then, having slightly warmed the surface of the urn to effect even coating, a number of applications of a solution of iron rust in vinegar or tea is applied with a grass brush to color the piece. A cast iron or bronze lid is then added to complete this chanoyu-gama, ready to take pride of place among the other items used in the tea ceremony.
The traditional techniques used in the making of Yamagata metal casting are special to this production center. They are techniques developed tirelessly over many generations by countless craftsmen, who have worked in the shadows of the 900 yearlong history of this craft in Yamagata. The same production process used to make a chanoyu urn is widely used in the making of such household items as kettles and cooking pots. It is also used for decorative items such as bronze flower vases and ornaments. It is even used in the manufacture of parts for cars and agricultural equipment.
