How to Make Raku

Raku is a pottery technique originated by Korean potters in 16th century Japan. It has been popularized in Western culture by famous potters and innovators such as Bernard Leach and Paul Soldner. Striking and colorful metallic finishes resulting from a quick firing process distinguish raku pottery from other types of ceramic ware. With painting, glazing and firing often accomplished within an hour, there is even a tradition of raku parties, for fun, sophisticated leisure.

Things You'll Need

• Raku Firing Kiln:
• Oil drum
• Angle grinder
• Propane weed burner and gas tank
• Regulator to monitor tank heat
• Stiff wire
• Ceramic fiber
• Ceramic glue for the fiber blanket
• Refractory bricks
• Kiln shelf
• Reduction Chamber:
• Straw or sawdust
• Large buckets (cleaned lidded paint buckets will do)
• Firing:
• Stoneware clay pottery
• Flame retardant gloves
• Large long tongs

Instructions

Make the Raku Kiln

1. Make the raku kiln yourself at home. After gathering the materials you need, completely clean out the oil drum and segment it 1/3 of the way down from the top, creating a kiln lid. You will probably need an angle grinder to cut the drum. The hole on the top of the lid where the oil knob once was will allow the heat to rise up and out.

2. Create a handle by rounding and attaching stiff wire to opposite ends of the lid so that you can lift it easily.

3. Cut a small hole near the bottom of the drum with a hammer and metal chisel so that you can stick the propane burner through.

4. Open the lid and line the drum with a layer (at least two inches thick) of ceramic fiber, using the ceramic glue.

5. Prop the kiln shelf in and place refractory bricks along the floor of the kiln. You may need additional propping to keep the shelf up.

Glazing Bisque-Fired Pottery

1. Select and mix your glaze recipe into a large bucket. You can find detailed raku glaze recipes online and in the tips section of this page.

2. Pour your glaze into the pottery, circling the glaze around so that it layers fully and evenly. If you are glazing a pot that has a large open face, such as a bowl, use different glazes for the inner face and the exterior creates an artful contrast. You can also use different glazes across the outer surface and can create patterns and designs by holding the pottery at an angle above the glaze bucket and wiping or splattering the glaze down across with utensils and brushes. Or you can dip the pottery entirely into the glaze and shake and hold it down to let the glaze soak and the excess fall back into the bucket.

3. Let the glaze dry.

Raku Firing

1. Place the pottery on the shelf of the raku kiln. Close the kiln lid and start it up by letting the gas flow in through the burner.

2. Regulate the heat so that it rises quickly but slows down at around 1,030 degrees F and shut it off when it reaches 1,830 degrees F.

3. Let the pottery remain in the kiln for two to three minutes after reaching the 1,830 degrees F maximum. Cycles can be as short as 15 to 20 minutes or long as several hours, depending on the pieces and firing requirements.

Reduction Chamber

1. Remove the pottery from the kiln with the tongs. Make sure you are wearing your gloves and that your reduction chamber is outside or on a patio where there is good air flow.

2. Nest the pottery into the reduction chamber, your buckets full of straw or sawdust.

3. Cover the pottery with the straw or sawdust so that the pottery is immersed in heat and flames.

4. Close the bucket lid. This traps the fire without oxygen so that oxygen is removed from the pottery glazes. Let your pots stay in the chamber 15 to 30 minutes to sustain color.

5. You can adjust color and glaze effect based on how long you keep the pottery in the chamber and the temperatures before, during and after the reduction process. The longer you let your pottery cool before placing it into the reduction chamber, the brighter the colors. Areas on the raku pots where you want more color to develop, you can spray with water before placing it into the reduction chamber. Also for brighter colors, hold the pottery in the air for 10 to 30 seconds before post-fire reduction. If you want a more metallic look with dark crackle lines, make sure you leave your pottery in the kiln as long as it takes for the pots to reach 1,830 degrees F and then quickly reduce, making sure you securely cover the lid of the reduction chamber.

Cooling

1. Remove the raku pottery with your tongs and place the pots on a platform to cool.

2. Dump the raku ware into a bucket of cool water.

3. Use a stiff brush to clean your pottery while it is cooling in the bucket.

4. Once cleaned and rinsed, dry the pottery so that the raku pots do not remain damp and fade in color.

Tips & Warnings

• Because it is fragile and porous, raku ware is more suitable for decorative than functional use. Raku pottery should be showcased or stored in a cool dry location.

• Remember to use a clay that contains a great deal of fire clay and similar refractory materials that can endure the extreme heat shock entailed in the process. These include most stock stoneware clays.

• This process involves high temperatures and should be undertaken with caution and guidance from an experienced recreational or professional potter.

References

• CeramicsToday.com: Raku Facts
• Time.com: Pottery. the Seventh Kenzan

Resources

• Raku Glaze Recipes