What temperature should you fire double glazed pottery?

Double glazed pottery should be fired at temperatures typically ranging from 2167°F to 2345°F (1186°C to 1285°C). This range allows the glazes to mature properly, ensuring a durable and attractive finish. However, the specific temperature depends on the type of clay and glaze used.

What Is Double Glazing in Pottery?

Double glazing refers to the process of applying two layers of glaze to pottery. This technique enhances the depth and richness of the final color and can create unique effects. The first layer is often a base coat, while the second adds texture or special effects, such as a glossy finish or intricate patterns.

How to Fire Double Glazed Pottery

Firing double glazed pottery requires careful attention to detail. Here is a step-by-step guide:

1. Bisque Firing: Begin with a bisque firing to harden the clay. This is typically done at lower temperatures, around 1832°F (1000°C).

2. Apply First Glaze: Once the bisque firing is complete, apply the first glaze layer evenly across the pottery surface.

3. First Glaze Firing: Fire the pottery again to mature the first glaze layer. This firing is usually done at cone 06 to cone 04, or approximately 1830°F to 1940°F (999°C to 1060°C).

4. Apply Second Glaze: After the first glaze firing, apply the second glaze layer. This layer can be decorative or functional, depending on your desired outcome.

5. Final Glaze Firing: The final firing should be at a higher temperature, typically cone 5 to cone 10, or 2167°F to 2345°F (1186°C to 1285°C). This step ensures that both glaze layers mature properly and fuse with the clay body.

Why Is Temperature Crucial in Firing?

Proper firing temperature is crucial for several reasons:

• Glaze Maturation: Each glaze has a specific temperature range at which it matures. Firing outside this range can result in underdeveloped or over-matured glaze.
• Clay Body Integrity: The clay body must also mature at the correct temperature to ensure strength and durability.
• Color Development: The final color of the glaze can vary significantly with temperature changes. Proper firing ensures the intended color and effects are achieved.

Common Problems in Double Glazed Pottery

Double glazing can present challenges. Here are some common issues and how to address them:

• Crazing: Fine cracks in the glaze can occur if the glaze and clay body expand and contract at different rates. To prevent this, ensure compatibility between the clay and glaze.
• Pinholing: Small holes in the glaze surface can result from trapped gases. Slow firing and proper ventilation can reduce this risk.
• Running: Glazes can run if applied too thickly or fired too high. Apply an even, thin coat and monitor the kiln closely.

Tips for Successful Double Glazing

• Test Glazes: Always test glazes on small samples before applying them to your final piece.
• Use Compatible Materials: Ensure that your clay and glazes are compatible to prevent defects.
• Monitor the Kiln: Use a reliable kiln with accurate temperature controls and monitor the firing process closely.

People Also Ask

What Is the Best Clay for Double Glazing?

Stoneware and porcelain are ideal for double glazing due to their ability to withstand high temperatures and their smooth surfaces, which accept glazes well.

Can I Use Any Glaze for Double Glazing?

Not all glazes are suitable for double glazing. It is essential to use glazes that are compatible with each other and mature at similar temperatures.

How Do I Know If My Glaze Is Maturing Correctly?

A mature glaze will have a smooth, even surface without defects such as pinholes or crazing. Conducting test firings can help determine the correct temperature range for your glazes.

How Long Should I Fire Double Glazed Pottery?

The firing time depends on your kiln and the specific glazes used. Generally, it can take several hours to reach the desired temperature, with additional time for cooling.

What Safety Precautions Should I Take When Firing Pottery?

Always follow safety guidelines, such as ensuring proper ventilation, wearing protective gear, and using equipment as instructed by the manufacturer.

Conclusion

Firing double glazed pottery requires precision and attention to detail. By understanding the appropriate temperature ranges and methods, you can achieve stunning results that are both functional and beautiful. Remember to test your materials, monitor the kiln closely, and always prioritize safety. For more insights into pottery techniques, explore related topics like glaze chemistry and kiln maintenance to enhance your pottery skills.