Creating a cast iron kettle

Nambu- tekki kettles (except mass-produced models) are produced by hand, using a traditional method perfected over generations. Their creation is an intricate and time-consuming activity which can only be carried out by craftsmen devoted to their craft. Looked after with care, they can last a lifetime.

testsubin mold making

Sand is scraped into the desired shape to create a mold

(photo: Kunzan Workshop)



The process begins at the design stage.

A sketch is made which is then transferred to a sheet of metal 1.5mm thick.

This forms the template for the mold.


Different textures of sand and fine soil are used to create the mold using a special scraping tool (see photo).



testubin mold with visible pattern

The inside of a fired mold showing a recessed design

(photo: Kunzan Workshop)

Various tools are used and designs vary from "Arare" (raised bumps at regular intervals) to incredibly detailed scenes of flowers and animals,some drawn using a transfer sheet and others completely freehand.

The imprinting of a design has to be done while the sand is still damp.

Working quickly to produce a balanced finish takes years of experience and a steady hand.



The mold is fired at 1300c.(704 F.) after being decorated.

handle knob molds

Individual molds for lid knobs

(photo: Kunzan Workshop)

Molds are also made for the lid knobs.Even pieces as small as these are crafted with precision. Thin lines of sand are placed on the inside of the molds to achieve the effect seen on the inset photo.

casting(poring the metal into the mold)

A moment of intense heat and intense concentration when the kettle is born!

(photo: Iwachu Cast Iron Works)

The outer mold consists of two halves. An inner mold (made of sand and clay) is sandwiched between the two, leaving a thin space into which the metal is poured. This thin space will become the kettle's body.



Metal is melted in a furnace to a temperature of about 1400c. to 1500c (760F. - 815F.).

The molds are placed on an ash pit and held stable with long wooden slats.

A long handle is attached to the pot holding the metal, which is then carefully poured into the molds, emitting sparks and small bursts of flame.

A very dramatic spectacle!

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testubin rust-proof coating

Kettles stacked up after the oxidisation process

(photo: Kunzan Workshop)

Once the metal has hardened, the molds are removed and the kettles are cleaned.

Each mold has to be repaired after almost every use and can only be used about 3-5 times. (1-2 times for delicate designs)

(Broken molds are not discarded but broken down and sifted back into sand in order to be used again).



Charcoal is heated to a temperature of 800c.(426 F.) and the kettles are steam-baked for 30-40 mins.

This results in an oxidized coating which helps protect against rust.

testubin-coating the pots

Finishing touches by an experienced craftsman

(photo: Kozan Workshop)





A pot is heated to 250c. and the urushi lacquer is applied to the pots with a straw brush, giving the kettle a glossy sheen.
Afterwards iron stain (Ferric tannate) is applied to the pot surface to gain the matte finish.




testubin-making the handles

Hammering sounds echo around the workshop

(photo: Tanaka Tsuru Blacksmith)

The kettles are completed with the application of a handle,made at a special workshop.

The most difficult handles to make are hollow. These are made by pounding a piece of iron until it is flat and then curling the edges inward. Hollow handles are prized as they are light and don't get as hot as the main body of the pot.


Hollow handles are applied to high-end models over approx. US$700.

The creation of one cast iron kettle consists of over a 80 processes all of which have to be mastered by the young craftsman, learning while he works.
However production is not all. Today's workshops have to be aware of their customers needs and are continually striving to create pieces which are relevant to modern lifestyles, while still staying true to their roots.

In a market overrun with mass-produced items, it is a pleasure to find craftsmen who are still investing time and attention in the creation of highly personal items, both beautiful to look at and practical to use. This introduction has been compliled using information gained by visiting various workshops in the Morioka area. While striving for a degree of accuracy, we have been obliged by the confines of space to condense certain processes. This has led to a general introduction which may not cover the differences between various workshops and craftsmen .We ask for understanding on this matter.