It all began in the early 17th century when the Nanbu clan, which ruled the area centered around present-day Morioka City in Iwate Prefecture, invited tea kettle makers from Kyoto to Morioka.
Later, the Nanbu domain summoned many foundry workers and tea kettle makers from various regions to produce weapons, tea kettles, and everyday items. The famous Nanbu iron kettle originated in the 18th century when tea kettles were made smaller and improved, and its ease of use led to its widespread use.
Meanwhile, in the region corresponding to present-day Oshu City, Iwate Prefecture, which was under the control of the Date clan, the production of cast iron everyday items was also thriving. After the Meiji era, technological exchange between the two production areas progressed, and in the 1950s, cast iron products made in both Morioka and Oshu came to be collectively called NAMBU Tekki (Cast Ironwork).

• Technology/techniques/raw materials

  Technology/techniques/raw materials

  Technology/techniques

  1. Mold making shall be carried out using the following techniques or methods:
  (1) It must be made from sand.
  (2) For the casting sand in the part that comes into contact with the molten metal, use "true clay".
  (3) The mold shall be made by "turning mold" or "filling mold".
  (4) When using a "turned mold", the surface of the mold shall be "patterned" or "textured".
  (5) Firing or drying the mold (including "surface firing").

   

  2. The surface of the casting shall be colored using lacquer and iron oxide.

   

  3. For items used as cooking utensils, "metallic sealant" must be applied.

   

  raw materials

  1. The material used for casting shall be iron sand or pig iron for casting.

  2. The lacquer used as a coloring agent shall be natural lacquer.

• Work scene

  Work scene

  Here, we will introduce the manufacturing process of iron kettles, a representative product of NAMBU Tekki (Cast Ironwork).
  Making an iron kettle involves more than 80 steps, and it can take nearly two months from design to the final product.
  There are two types of craftsmen who make iron kettles: one who creates the body and another who specializes in the handle. It is only when the skills of these two craftsmen come together that a truly magnificent piece is created.

  Step 1: Drawing

  First, I draw the shape of the iron kettle I want to make on paper. While iron kettles are generally made in round or flat-round shapes, I also make original designs.
  Next, a cross-sectional view is determined from the drawing, and a "wooden pattern" for making the casting mold is made from sheet metal. Although this pattern is made of sheet metal, the name "wooden pattern" remains because wood was used in the past.
  Three wooden molds are needed for the iron kettle: a mold for the upper half of the body, a mold for the lower half of the base, and a mold for the lid. These wooden molds are rotated to create each of the molds.
  In many cases, when creating the wooden mold for casting, a wooden mold for the inner core (nakago) that will be placed inside the mold is also made. The inner core is used to create the hollow space inside the iron kettle, and the wooden mold for the inner core is smaller than the mold that makes the outer shell by the thickness of the iron kettle.

  

  Step 2: Mold making

  River sand, clay, and a clay syrup called "hajiru" are mixed together and placed in an unglazed outer frame called a "sanegata." A wooden mold is placed in the center of the sanegata and rotated to create a casting mold.
  The river sand is refined in three stages to match the shaping process. First, a rough shape is created using coarse sand, and the mold for the spout is embedded and attached to the main body. Next, the sand mixed with the clay is made slightly finer to refine the shape. Finally, very fine sand sifted through silk is used to create a smooth inner surface that comes into contact with the pouring iron.

  

  Step 3: Pattern pressing and surface finishing

  The pattern pressing process takes place before the mold dries. The "arare" pattern, famous for Nambu iron kettles, is created by pressing 3,000 patterns one by one using a pressing tool. In addition to geometric patterns, some kettles are decorated with pictures of flowers, landscapes, and other subjects using various tools, resulting in a relief-like finish.
  One of the charms of Nambu iron kettles is the process of creating a textured surface, which is called "hadauchi." This involves sprinkling finely ground sand onto the body, applying a mixture of sand and clay dissolved in clay syrup to the body using a cloth tampon, or applying it to the surface of the body with a brush to create the desired texture.

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  Step 4: Core Making

  Using the wooden mold for the core that was made earlier, a core mold is made in the same manner as the casting mold, and the mold is fired. River sand, baked sand (sand that has had impurities removed by firing), and clay paste are mixed together to make the core sand. The core mold is placed on a potter's wheel, and the core sand is pressed into the inside of the mold to form a bowl shape, creating the body and bottom molds of the core. The finished body and bottom molds are glued together with clay paste, and dried thoroughly in the sun to completely remove the moisture from the core.

  Step 5: Drying and firing the mold

  After the body and tail molds are dried, they are fired over charcoal at around 800-1000 degrees Celsius for about two hours. Any small cracks that occur during this process are repaired with a brush or spatula. (De-aeration)
  Next, a runner is created in the base mold for pouring in the molten iron. Similarly, a runner is created in the mold for the lid, completing the mold making process. Finally, oil fumes are poured inside the mold to cover the surface and prevent the molten iron from sticking to the mold.

  

  Step 6: Mold assembly

  The body mold is placed face down, and the core is placed inside. Two or three small pieces of iron called "katamochi" are placed on the bottom of the core, and the bottom mold is placed on top of them. The katamochi are used to prevent the core from floating when molten iron is poured in, and they become part of the cast iron.

  Process 7: Casting

  Molten iron is produced by melting pig iron in a large melting furnace called a "koshiki," which is over 3 meters tall. In addition to coke fuel, pig iron, scrap iron, limestone, and other materials are placed inside the melting furnace. Inside the furnace, the materials melt and mix at a high temperature of 1,300 to 1,400 degrees Celsius. The molten iron is called "yuru" (molten metal). The yuru that flows out of the melting furnace outlet is received with a ladle called a "toribe," which has a red clay interior, and poured into the mold through the runner.

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  工程8： 仕上げ

  Once the mold has cooled, it is opened and the product is removed. Next, the core is broken up with a metal rod, and any sand adhering to the inside is carefully removed.
  Any excess molten iron that spills out from gaps such as the seams of the mold is hammered and filed down to shape it, and then the entire piece is finished neatly with a wire brush.
  The finished iron kettle is fired over charcoal at a temperature of 800 to 1,000 degrees Celsius to create a magnetic oxide coating. This process is called "rust prevention," and the resulting coating prevents rust. The rust prevention technique originated with Nambu iron kettles.
  Because the outside of the iron kettle is exposed to direct heat and has uneven heating, the oxide film on the outside should be removed by scrubbing with a wire brush or similar tool.

  

  Step 9: Polishing and coloring

  The kettle is inspected for leaks, and if there are no problems, the coloring process begins. The finished iron kettle is heated over charcoal to a temperature of about 200 degrees Celsius to prepare the surface for application of the finishing lacquer or the ohaguro solution, which is a mixture of iron rust, acetic acid, or tea juice. While the iron kettle is still hot, lacquer is applied with a brush made of kugo grass and then baked on. The iron kettle, which has been undercoated with lacquer, is then finished by applying either ohaguro or tea juice with a brush.

  

  Step 10: Making the vines

  Since the handles are made by forging, they are produced by craftsmen specializing in handles. There are two methods: "bag handles," which are made by rolling a single sheet of iron, and "wood handles," which are made by bending a round rod. "Bag handles" are a very elaborate technique, and only a few people are able to perform this technique.
  The main body has been given a colored finish, and once the handle is attached, it's complete.

  

   

• Close-up

  Close-up

  Morioka's NAMBU Tekki (Cast Ironwork) a representative example of traditional crafts.

  Boiling water, brewing tea NAMBU Tekki (Cast Ironwork) adds color and tranquility to those moments. Morioka's cast iron is so well-known throughout Japan that it's often mentioned when talking about traditional NAMBU Tekki (Cast Ironwork). Nurtured by the rich natural environment of the Nanbu region, it has warmed the daily lives of its inhabitants.

   

  The history of NAMBU Tekki (Cast Ironwork), alongside the Nanbu clan.

  NAMBU Tekki (Cast Ironwork) received its first designation as a traditional craft in 1975. The history of NAMBU Tekki (Cast Ironwork) dates back 350 years, beginning in the mid-17th century when the Nambu clan built Morioka Castle. Morioka, which had abundant raw materials such as iron sand and wood for charcoal, subsequently became known throughout Japan as a major production center for cast iron.
  Initially, only tea kettles were made, but through continuous refinement, in addition to the iron kettles that have become synonymous with NAMBU Tekki (Cast Ironwork) a variety of everyday items such as pots, wind chimes, and accessories are now produced.
  In recent years, NAMBU Tekki (Cast Ironwork) has been experiencing a resurgence in popularity, not only for its aesthetic beauty but also for its practicality, thanks to the growing awareness of the health benefits of iron leaching from it. We visited "Morioka Handmade Village," a collection of workshops that produce NAMBU Tekki (Cast Ironwork), and spoke with the owners.

  

  The world of craftsmanship is endless, no matter how high you go.

  "It takes 3 to 5 years to be able to make something that can be sold, but in this world, there's no end to how far you can go," said Maeda, the owner of Torayama Workshop, one of the five workshops in Morioka Handmade Village. Including Maeda, three craftsmen are working hard to make ironware. "I originally worked in sales for NAMBU Tekki (Cast Ironwork), but I've been making it myself for 20 years now." "It's a fun job if you can persevere for 5 years, but a lot of people quit." In the world of craftsmen, where skills are cultivated through steady daily effort, patience to acquire skills through years of effort and a spirit of inquiry to further refine those skills are indispensable qualities.

  

  (Craftsman)

  A job that blends tranquility and ferocity.

  Among the many delicate tasks performed by artisans, often carried out silently and without a sound, ironware making stands out for its roughness. Mr. Maeda, while telling me his story, files the spout of an ironware. "This makes a huge difference in how easy it is to pour." The sound of filing the iron resonates in my head at a pitch not heard in wooden products. In the cupola where the iron is melted, the iron boils at a scorching temperature exceeding 1,300 degrees Celsius. In contrast, the process of pressing patterns that give the iron kettle its character onto the mold is completely silent. This silent process is repeated 3,000 times for each iron kettle. Rough work and quiet work are repeated, and the ironware is completed.
  And in contrast to the loud noises produced by the work, the craftsman remains silent. The meticulous work continues silently in this harsh environment.

  

  The sound of a file grinding resonates.

  Are iron tools difficult to handle?

  "Many people think that iron kettles must be boiled over charcoal, but that's not true. You can boil water over gas. The important thing is that you use it." Many people think that iron kettles rust easily, or they are too particular about it. "Here, once the water boils, we transfer it to a thermos. The iron kettle is hot, so if you empty the water and leave it, it will dry quickly. That's all it takes to prevent rust." With just a little care, an iron kettle can withstand long-term use. Without that little bit of care, an iron kettle might not add any color to your life.

  

  Iron kettles, which can be repaired even if they develop holes, also contribute to resource conservation.

  Product development and talent development that look ahead to the future.

  In recent years, from a disaster prevention perspective, there has been an increase in apartments equipped only with induction cooktops and no gas stoves. Mr. Konno, secretary-general of NAMBU Tekki (Cast Ironwork) Cooperative Association, is actively working on developing new products to suit this living environment. "Compared to stainless steel kettles, they conduct heat better and boil faster." He is also actively involved in making iron kettles for induction cooktops. Mr. Konno is working with craftsmen to encourage them to create products that are in line with the times. It is these efforts that are quietly supporting the popularity of NAMBU Tekki (Cast Ironwork).
  They are also actively recruiting successors from outside the prefecture. Compared to the glamour of the outside world, it is a humble world of craftsmanship, but many young people are drawn to the appeal that "NAMBU Tekki (Cast Ironwork) is a local tradition that we can be proud of to the world. We want young people with the spirit to carry on this technique to join us."

  NAMBU Tekki (Cast Ironwork) is being re-evaluated from the perspectives of health and energy conservation. By learning about its production methods and the dedication of the craftsmen, your daily tea time is sure to become even more fulfilling.

  

  The polygonal iron kettle, which is difficult to manufacture, is a product developed by Torayama Kobo.

  Craftsman Profile

  ​Tomoyuki Maeda

  He is the owner of Kozan Workshop and a certified traditional craftsman. "You never know until you open the mold. Casting is like a demon," he says, his concentration on his work never wavering, even with his advanced skills.

  Anecdotes

  Happy reactions: Letters from children

  There is a curriculum in the 5th grade of elementary school in which students learn about traditional crafts from various regions. Among the traditional crafts NAMBU Tekki (Cast Ironwork) is well known and attracts many children to visit the workshop. It seems that the children who visit often send letters afterward, and the letter in the photo is one example. The elaborate manufacturing methods and skilled techniques of traditional crafts seem to impress not only adults but also children, and the letters convey the children's surprise and curiosity. It seems that the artisans and members of the association are very pleased with these kinds of reactions. Learning about traditional crafts may be an ideal way to learn about things as a whole, not just the techniques, but also the changes in local culture and history, and the way of working.
  Many of the letters received were handwritten, with drawings and writing that showed great individuality. However, some, perhaps reflecting modern times, were professionally made, incorporating images from computers or using word processing software. These felt somewhat bland, considering they were made by children. Perhaps even letter writing requires the skill of handwriting?

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    Numerous thank-you letters and reports received from children.