How to Pit Fire Pottery

Pit firing is an ancient method of firing pottery that has been used for thousands of years, long before the invention of kilns. This traditional technique uses an open fire to harden clay pieces, making it accessible and deeply connected to nature. One of the most appealing aspects of pit firing is its ability to create unique, unpredictable finishes.

The flames, smoke, and materials used during the process leave behind natural variations in color and texture, adding character and individuality to each piece. For hobbyists and artists alike, pit firing is a rewarding process that blends creativity with craftsmanship.

This article serves as a step-by-step guide on how to pit fire pottery, covering everything from preparation and materials to the finishing touches, helping you bring your pottery to life while celebrating the beauty of tradition.

Materials and Tools Needed

Pit firing pottery requires a variety of materials and tools to ensure a successful and creative process. Below are the essentials you’ll need, categorized for ease:

Pottery Materials

• Bone-dry, unfired clay pots (preferably made from low-fire clay): The project’s foundation should be fully dried before firing. 
• Optional: Burnishing tools can achieve a smoother surface on your pottery, enhancing the polishing effect post-firing.

Firing Materials

• Sawdust, wood shavings, or dry leaves: These items act as insulation, helping to control the distribution of heat within the pit. 
• Hardwood, softwood, or charcoal: These materials are your primary fuel, providing the heat necessary for the firing process. 
• Metal container or bricks: Essential for constructing the pit, ensuring adequate containment and protection for the pottery during the firing.

Color and Effect Materials

• Salt, copper carbonate, or iron oxide: Adding these natural substances can result in unique coloration and finishes on fired pottery. 
• Banana peels, coffee grounds, or seaweed: Organic materials can create intriguing and organic patterns, contributing to the individuality of each piece.

Safety Equipment

• Heat-resistant gloves: Essential for protecting your hands while managing the fire and pottery. 
• Safety glasses: These guard your eyes against flying sparks or debris. 
• Long tongs: Useful for safely handling the hot pottery during or after firing.

These materials will set you up for a successful and enjoyable pit firing experience.

Preparing the Pottery for Pit Firing

Step 1: Choosing the Right Clay 

Selecting the correct type of clay is crucial for successful pit firing. Opt for clay with a low-fire rating, such as earthenware, as it is better equipped to handle the thermal shock during the firing process. Clays that are labeled as suitable for pit or raku firing are ideal. Avoid high-fire clays, as they may crack or fail under the intense conditions of an open flame. 

Step 2: Drying and Burnishing 

Before firing your pottery, ensure that every piece is dry to prevent cracking or explosions caused by trapped moisture. Allow the pottery to air dry thoroughly or place it in a warm, dry environment to accelerate the process. For those seeking a glossy, polished finish, consider burnishing the pieces.

Use a smooth stone or the back of a spoon to gently rub the surface of the clay, compressing and smoothing it. This optional step enhances the aesthetic appeal and adds a protective layer. 

Step 3: Pre-firing Decoration 

To add a personal touch, decorate your pottery with natural elements before firing. Apply leaves, feathers, or minerals to the clay’s surface, leaving unique patterns during the firing process. You can also experiment with organic materials like seaweed or salt to create intriguing effects. These decorations are an excellent way to infuse artistry and individuality into your work.

How to Pit Fire Pottery: Building the Pit for Firing 

Step 1: Choosing a Safe Location 

Select an outdoor area that is free from flammable materials and far from buildings, trees, or dry grass. Safety is paramount, so ensure the location is well-ventilated and easy to monitor. Once you’ve identified your spot, dig a pit at least 12–18 inches deep and wide enough to accommodate your pottery. A well-sized pit helps contain the fire and ensures consistent heat for an even firing process.

Step 2: Lining the Pit 

To prepare the pit for firing, add a layer of sawdust or wood shavings at the bottom. These materials create a base fuel layer that burns slowly and helps to distribute heat evenly. For better heat retention, line the sides of the pit with bricks or metal sheets, which also prevent the soil from collapsing during the firing. This step ensures the pit maintains a steady temperature to achieve optimal firing conditions.

Step 3: Arranging the Pottery 

Carefully position your pottery inside the pit, ensuring that no pieces are in direct contact with each other to prevent breakage. Layer organic materials such as banana peels, sugar, or salt between the pots to add creative color effects.

These elements react with the heat during firing, leaving behind distinct markings and vibrant hues. Arrange everything methodically to protect your pottery and achieve the best artistic results during the firing process.

Starting and Controlling the Fire

Step 1: Igniting the Fire 

Add small pieces of dry wood and kindling over the arranged pottery to begin the firing process. Ensure the materials are evenly distributed to create consistent heat across the pit. Use a torch or a long lighter to ignite the kindling gradually. Avoid rushing this step, as a slow start helps in preventing thermal shock, which could crack or damage the pottery.

Step 2: Maintaining the Fire 

Once the fire has been successfully ignited, maintain it by carefully adding more wood over time. Begin with smaller pieces and slowly transition to larger logs, ensuring a steady and even heat distribution over the pottery.

This stage requires patience; avoid making sudden or excessive adjustments to the fire, as rapid temperature fluctuations may compromise the integrity of your pottery. Keep a watchful eye on the fire, making adjustments as needed to sustain optimal heat levels.

Step 3: Allowing the Fire to Burn Down 

After several hours, when the fire has reached its peak and the heat has penetrated the pottery fully, allow the flames to begin subsiding naturally. As the fire burns down, the pottery will gradually be enveloped in hot embers.

Cover the pit carefully with a metal sheet or a layer of dirt to trap the residual heat, ensuring that it remains consistent for several additional hours. This step is crucial for achieving strong, well-fired pottery with unique color effects from the organic materials added earlier.

Cooling and Removing the Pottery

Step 1: Allowing the Pit to Cool 

After the firing process, allowing the pit to cool naturally is essential. Do not rush this step, as rapid cooling can cause the pottery to crack. Leave the pottery in the pit until the embers have completely burned out and cooled, which may take up to 24 hours depending on the size and depth of the pit. Patience during this stage ensures that the pieces cool evenly, preserving their structural integrity.

Step 2: Carefully Extracting the Pottery 

Once the pit is completely cool, use protective equipment such as tongs or heat-resistant gloves to extract the pottery carefully. Handle each piece gently to avoid damage, as the pottery could still be fragile. Avoid splashing water directly onto the pieces during this stage, as sudden temperature changes might cause cracking or breakage.

Step 3: Cleaning and Inspecting the Pieces 

Once removed, clean the pottery by brushing off any residual ash or dirt using a soft cloth or brush. This will reveal the unique textures and color variations created during the firing process. Inspect each piece thoroughly for any cracks or imperfections that may have formed. These distinctive marks add to the pottery’s character and represent the natural, hands-on crafting process.

Finishing the Pit-Fired Pottery 

Step 1: Polishing and Sealing 

To enhance the natural colors and textures of the pit-fired pottery, apply a thin layer of wax or oil to the surface. This step not only enriches the piece’s visual appeal but also adds a slight protective layer against dust and minor abrasions. Be sure to use a soft, lint-free cloth to spread the wax or oil evenly across the pottery, paying attention to intricate details. 

Step 2: Buffing for Shine 

After sealing, use a clean, soft cloth to buff the pottery gently. This process brings out a subtle shine, highlighting the unique finishes

. Buffing also helps to smooth out any inconsistencies in the sealing layer, giving the pottery a refined, polished appearance. Take your time to ensure an even and glossy result. 

Step 3: Displaying or Using the Pottery 

Pit-fired pottery is best suited for decorative purposes, as its porous nature makes it unsuitable for holding food or liquids safely. Display your finished piece in a prominent location to showcase its handcrafted charm and organic beauty. Whether placed on a shelf, incorporated into a centerpiece, or used as a planter, each unique creation tells the story of its artisanal origins.

Common Pit Firing Issues and Troubleshooting 

Pottery Cracking 

Cause: Uneven heating or cooling during the firing process. 

Solution: To minimize the risk of cracking, allow the fire to rise gradually in temperature. Avoid sudden temperature shifts that can stress the clay. Once firing is complete, ensure the pottery cools slowly by smothering the fire in ash layers or leaving the pieces in the kiln until fully cooled. 

Faint or Uneven Coloration 

Cause: Insufficient use of chemical additives or organic material during the firing process. 

Solution: Enhance the vibrancy and uniformity of colors by experimenting with various organic materials, such as wood chips, leaves, and sawdust, as well as oxides and salts. Adjusting the placement of these materials around the pottery can also influence the final effect. 

Warped Shapes 

Cause: Uneven firing conditions or improper stacking of pieces. 

Solution: Carefully arrange pottery in the pit to ensure even heat distribution. Avoid overcrowding and use supports to maintain the shape of pieces during the firing process. Keeping a balanced fire and consistent heating will help preserve the intended forms of your creations. 

Conclusion

Pit firing pottery is a timeless and fascinating method combining artistry with nature. The process involves preparing the clay pieces, carefully constructing the fire, controlled cooling, and finishing touches to reveal the final masterpiece. Each stage contributes to the uniqueness of the result, with patterns and colors distinct to every piece.

The beauty of learning how to pit fire pottery lies in its unpredictability and creative possibilities. For the best results, experiment with various natural materials, like organic additives and oxides, to craft truly one-of-a-kind works of art that celebrate individuality and craftsmanship.