How to Build a Kiln for Raku Pottery

Because it is made of bricks, your kiln for raku firing can be easily disassembled.

The first raku pottery was made in Japan during the late 16th century. But it wasn't until around 1911 that this type of pottery was introduced to the Western world. The process of creating raku pottery is the same today as it was centuries ago, and involves the rapid heating and cooling of pottery during the firing process. When firing glazed pottery in a raku kiln, the extreme temperature fluctuations produce the highly desired cracks and fractures associated with glazed raku pottery.



Although they are usually quite expensive, raku kilns can be purchased from some art suppliers. Building your own outdoor kiln for raku pottery requires only simple supplies, such as sawdust and bricks, and may be as effective as a commercially produced kiln.

Things You'll Need

• 100 ordinary, red bricks
• Sawdust
• Dried (greenware) or glazed pottery
• Metal trash can
• Metal lid, such as a trash can lid wide enough to fit over the top of the kiln
• Lighter or matches
• Small stone
• Newspaper
• Soft sponge
• Tongs
• Water
• Fire extinguisher

Instructions

Constructing The Kiln

1. Select a level spot outdoors, at least 15 feet from any buildings. Lay a square-shaped base section of about 15 to 20 bricks on the ground.

2. Place another layer of bricks on top of the bricks along the edge of the first layer, leaving about 1/4-inch between the newly placed bricks. Place another layer of bricks on top of the second layer, continuing to leave about 1/4-inch of space between the bricks. Build layers of bricks in this manner, until the kiln reaches your desired height.

3. Add about four inches of sawdust to the bottom of your brick kiln. Lay your dried pieces of pottery in the sawdust at the bottom of the kiln; the pieces should be arranged vertically.

4. Add more sawdust to the kiln, filling the areas between the pottery. Cover the tops of the pottery with one or two inches of sawdust. Layer any remaining pieces of pottery to be fired on top. Cover these pieces with more sawdust. Continue layering and stacking pottery and sawdust in this manner until all the pieces are in the kiln, finishing with a final layer of sawdust.

Firing The Kiln

1. Place crumpled newspaper on top of the sawdust inside the kiln. Make sure that your fire extinguisher is nearby, in case it is needed. Then, light the newspaper on fire. Cover the kiln with the metal lid. Prop the lid slightly, using your small stone.

2. Check the fire after one or two minutes, to make sure it is still lit. Allow the fire inside the kiln to burn overnight. Assign several people to take turns monitoring the kiln during the night, making sure they have access to the fire extinguisher.

3. Remove the pottery from the kiln when the fire has stopped burning, using tongs, if needed. Wash the ashes away from the pottery using a sponge dipped in water.

4. Scoop up the sawdust ashes and place in a metal trashcan. Cover the ashes with water and allow the ashes to soak for 24 hours. This will prevent any fires from being started by the smoldering ashes.

Tips & Warnings

• Keep your fire extinguisher nearby at all times while using your kiln. Make sure that the fire extinguisher is in clear view so that all people who are taking turns watching the kiln will be able to access it.

• To avoid property damage or bodily injury, you should always be careful when working with any type of fire. You may need to check with your local fire department to make sure you are allowed to build such a kiln in your area.

• Avoid firing the kiln on a windy day. The wind may cause smoldering ashes to blow away, possibly causing a fire.

• Excessively dry conditions may cause objects around your kiln, such as dried grass, to catch on fire. To prevent this, moisten any dried grasses or leaves surrounding your kiln with a hose.

• Do not build the kiln too tall. Remember that you will need to be able to lean into the kiln to place your pottery inside.

References

• Fairfax County Public Schools: Department of Instructional Services: Outdoor Kiln Firing, page 10
• Lockett Pots: Raku