Hosted at my studio at the Fyansford Paper Mill, we arranged the expertise of Ray & John to show us the start of finish of a typical raku firing. Ray & John arrived equiped with a gas kiln on a trailer, the appropriate glazes and tools for decorating and metal garbage bins for the reduction and water dunking/cooling processes!

Raku firing is a unique and exciting process in pottery that originated in Japan. It’s known for its unpredictability and dramatic results. These pieces are decorative only, getting to around 1000c, the pieces are not vitrified and not for use for door.

Here’s a general overview of how a raku firing typically works:

Preparation: Before the firing begins, the potter creates their pottery pieces using raku clay, which is specially formulated to withstand the rapid temperature changes of the raku firing process. The pieces are then bisque-fired to a low temperature to remove moisture and prepare them for glazing.

Glazing: Once bisque-fired, the pottery pieces are glazed using raku glazes, which are typically formulated to mature at lower temperatures. Raku glazes often contain materials like copper, iron, and other metallic oxides that can create striking colors and effects when exposed to the unique firing conditions.

Firing: The glazed pottery pieces are placed in a raku kiln, fuelled by propane or natural gas. The kiln is heated rapidly to temperatures ranging from around 1000°C to 1040°C. Each firing took around 2 hours to reach temperature.

Reduction: Once the pieces reach the desired temperature and the glazes have melted (and are visually bubbling!), they are removed from the kiln while still glowing hot using long metal tongs or other tools. The hot pottery pieces are then placed into a metal bin filled with combustible materials such as sawdust, newspaper, or leaves. This metal garbage bin is often called a “reduction chamber” or “raku bin.” The newspaper also helps cushion the pots being layered inside the bins.

Post-Firing: As soon as the pottery pieces are placed in the reduction chamber, the combustible materials ignite from the intense heat of the pottery. The chamber is then covered, creating a reduction atmosphere where the lack of oxygen causes chemical reactions in the glazes, producing unique colors, textures, and patterns on the pottery surface.

Non reduction decorating: Pieces can be removed from the kiln, and rather than being placed in the reduction bins, they can be decorated with horse hair, feathers or leaves.

Cooling: After a short time in the reduction chamber (around 20 minutes), the pottery pieces are removed and cooled rapidly using water or by allowing them to cool in the open air. This rapid cooling helps to set the glazes and finishes the raku firing process.

Cleaning and Finishing: Once the pottery has cooled, it is cleaned to remove any remaining ash or soot from the reduction process. Some potters may choose to further enhance the surface of their raku pieces through techniques such as polishing or applying additional layers of glaze.

It’s important to note that raku firing can be somewhat hazardous due to the rapid temperature changes and exposure to combustible materials, so proper safety precautions should always be taken. Additionally, the unpredictable nature of raku firing means that each piece is truly one-of-a-kind, making it a favourite technique among potters and collectors alike.

We had such a great day! Everyone was buzzing – such a fun way to catch up with friends, colleagues and community, new friends and old! Thanks to everyone who came along for the day!
We will list more Raku classes based on demand, so if you are interested in our next raku workshop, please get in touch to register your interest.

Elizabeth x