Introduction to Raku Pottery
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Introduction to Raku Pottery
What is Raku Firing?
Raku firing is an exciting and unpredictable pottery technique that originated in Japan. Known for its rapid cooling process, raku creates unique, dramatic finishes on ceramic pieces. The process involves removing pottery from the kiln while it’s still red-hot and cooling it quickly, often in combustible materials.
Why Choose Raku?
Raku firing is ideal for potters seeking spontaneity and artistic experimentation. Its unpredictable nature and striking results make it a favorite among ceramic artists looking to push creative boundaries.
Keep in mind that none of the glazes used in Raku firing are food safe because the kiln is only heated to 1,800°F (982°C). That is why Raku pottery is used for decorative purposes because the glaze does not vitrify.
Key Characteristics of Raku
Crackle Patterns: Created by rapid cooling, crackle glazes form intricate lines on the surface.
Metallic Effects: Reduction firing enhances the metallic tones in certain glazes.
Organic Variations: No two raku pieces are alike, making each one a distinctive work of art.
Supplies
Before you get started, it’s important to have the right supplies to make Raku pottery. This checklist has everything you need:
- Clay
- Glaze
- Wax Resist
- Kiln or Kilns
- Extra Long Metal Tongs
- Heat Resistant Gloves
- UV protection Safety glasses
- Reduction Chamber (can with lid)
- Sand
- Combustible material
- A sponge with an abrasive cleaning pad
- Soap
Color of your Clay
The color of your clay determines how it will respond to the compostable materials, reduction chamber, and glazes. Darker clays produce more muted tones, whereas lighter clays yield brighter colors.
Glazing the Bisqueware Before Raku Fired
Apply low-fire glazes to the ceramic pieces for an interesting and unique look.
When applying glaze to raku ceramics, you want to apply 2 to 3 layers of glaze. You don’t want the raku glaze to be too thin because that will affect the end result. Apply three coats to your bisqueware. Check the thickness of the glaze with your fingernail. The glaze should be the thickness of a t-shirt.
Stains and Oxide
You can get creative and add oxides like Red Iron Oxide. Stains, and other additives in combination with your glaze or alone in order to create unique effects on finished pieces.
For example, copper oxide can produce vibrant blues when combined with an iron-rich base glaze, while cobalt oxide yields deep purples when applied over lighter-colored slips.
Wax and Film Resist
After your pot has been bisque fired, you can apply wax resist, or film resist to your pot. Wax Resist is a water-based coating to prevent color from adhering when glaze is applied to bisque or greenware.
Make a pattern any way you want with Wax Resist, then glaze your ceramics. Wipe away the glaze from the wax resist and fire. After the firing, The area where the wax was applied will burn off and leave a black matted surface to create a unique look.
Mayco AC-302 Wax Resist repels color when brushing underglaze or glaze or when dipped glaze is applied over it. It can be used for waxing the foot of thrown pieces before glazing or using as a decorative design technique. The product is blue out of the jar so when painting with it, you can easily see where it’s applied.
The Raku Process
Preparation:
- Use a raku-specific clay body that can handle thermal shock. Alabama Art Supply carries Smooth Raku MC117 and Raku Lite MC138 from Alligator.
- Apply glazes designed for raku firing, which often yield vibrant or metallic effects.
Firing:
- Heat the kiln to around 1,800°F (982°C).
- Carefully remove the red-hot pieces with long-handled tongs.
Reduction:
- Place the pottery into a container filled with combustible materials like sawdust, newspaper, or leaves.
- Cover the container to create a reduction atmosphere, which alters the glaze’s chemistry and results in unique finishes.
Cooling:
After a few minutes, remove the pottery and allow it to cool in open air or water.
Safety Considerations
- When making Raku pottery, safety should always be your top priority. If you are a beginner, you need to be extra careful. Besides having your protective gear like gloves and eyewear, you should also make sure your arms, legs, and feet are protected.
- Work in a well-ventilated area or outdoors to avoid inhaling fumes.
- Wear protective gear, including heat-resistant gloves and a face shield.
- Wear long pants and shoes that cover your feet. Wear a long sleeve shirt or arm protectors.
- No clothing or long hair hanging down. You don’t want anything to catch fire.
- Make sure you are at a safe distance from the kiln when it is opened. If you are opening the kiln, do not lean into it because a gust of hot air will be released during the kiln opening.
- Make sure you use extra-long tongs, and caution should be taken when lifting the fired pots out of the kiln, as the red-hot pots can cause serious burns if not handled properly. It is a good idea to practice lifting your pottery with the long metal tongs before doing the real thing.
- Use tongs and tools specifically designed for raku firing.
Additional Considerations for Raku
Glaze Choices: Raku glazes often contain materials like copper carbonate or cobalt oxide, which create vivid colors and metallic effects. Experiment with different formulas to achieve your desired results.
Surface Decoration: You can add texture or patterns to the clay body before firing to enhance the unique effects of raku firing. Carved or stamped designs become highlighted by the glaze and reduction process.
Environmental Impact: Be mindful of the materials used in reduction firing. Choose organic, non-toxic combustibles, and always work in a well-ventilated area.
- Elizabeth Ragona