How to Bisque Fire

Bisque firing is an essential step in the pottery-making process that involves firing clay pieces at a lower temperature to prepare them for glazing and final firing. This initial firing transforms the clay from its fragile, unfired state into a porous and durable material, making it easier to handle and absorb glazes effectively. Understanding the bisque firing process is crucial for achieving quality results and ensuring the longevity of your ceramic creations.

In this article on how to bisque fire pottery, we will cover the basics of bisque firing, including the materials needed, different techniques and methods, as well as some tips for success. Whether you are a beginner or an experienced potter, read on to learn more about this important step in the pottery-making process.

Materials Needed

To bisque fire your pottery pieces, you will need a kiln and kiln furniture (shelves, stilts, etc.), cone supports, pyrometric cones, and firing cones. In addition, you will also need the following materials:

Bisque Clay

This is a type of clay that has already been fired once at a low temperature to remove water and carbonaceous materials. It is porous and easier to work with than raw clay.

Glazes

These are used to add color, texture, and other decorative elements to your pottery pieces. There are various types of glazes available in the market, such as matte, gloss, crackle, etc., so choose one that best suits your desired outcome.

Tools

Some common tools used for bisque firing include a sponge or cloth for cleaning off excess glaze from the edges of the piece, tongs for handling hot pieces, and a heat-resistant glove for protecting your hand while loading and unloading the kiln.

6 Step-by-Step Guidelines on How to Bisque Fire

Step 1: Prepare Your Pottery Piece 

Before beginning the bisque firing process, ensure that your pottery piece is completely dried. This is commonly referred to as the “bone dry” stage, where the clay is free of any visible moisture and feels room temperature to the touch. It’s crucial to allow sufficient drying time to prevent any cracking or breakage during firing.

Carefully inspect the piece for any imperfections or dust, and clean it with a soft sponge or cloth to remove debris. At this stage, you can also smooth out any rough edges to refine the final shape. Proper preparation sets the foundation for a successful bisque firing.

Step 2: Bisque Firing

The bisque firing process involves heating the clay piece to a specific temperature range, typically between 1650°F and 1940°F (900°C-1060°C), depending on the type of clay used. This process transforms the soft, pliable material into a hard, durable ceramic form.

During the firing process, organic materials such as plant fibers or even tiny air bubbles within the clay will burn away. This creates microscopic pores in the clay body, making it more porous and allowing glazes to adhere better during the next firing. It also strengthens the piece by removing any remaining water molecules.

Step 3: Glazing

Once the initial firing is complete, the piece is ready for glazing. Glazes are made from a combination of minerals and oxides that are melted onto the surface of the ceramic piece. They can be applied in various forms such as liquid, powder, or suspended in water.

The glaze application process involves dipping, pouring, brushing, or spraying the glaze onto the surface of the pottery. The thickness and evenness of the glaze application will affect the final appearance and functionality of the piece.

Step 4: Firing the Glaze

After the glaze has been applied, the piece is ready for its final firing. This firing process will melt and fuse the glaze minerals onto the ceramic surface, creating a smooth, glass-like finish.

The temperature and duration of this final firing depend on the type of clay and glaze used. It is important to follow the specific instructions for both materials in order to achieve the desired results. Once the firing is complete, you can remove your pottery from the kiln and admire your finished creation. However, there are still some additional finishing touches that can be done to enhance your piece even further.

Step 5: Decorating and Finishing

One way to add unique and personal touches to your pottery is through decorating and finishing techniques. This can include adding designs or patterns, carving into the clay, or adding additional layers of glaze for a more intricate look.

There are various tools that can be used for decorating and finishing pottery such as brushes, stencils, sgraffito tools, and slip trailers. These tools allow you to create different textures and designs on your piece.

Step 6: Firing

Once your pottery is completely dry, it’s time to fire it in a kiln. This process involves heating the pottery to extremely high temperatures, typically between 1700 and 2300 degrees Fahrenheit.

Firing serves two purposes: first, it hardens the clay into a durable and long-lasting material. Second, it creates a chemical reaction with the glaze that gives your piece its final color and finish. There are different types of firing techniques such as bisque firing and glaze firing. Bisque firing is done at a lower temperature and only hardens the clay, while glaze firing is done at a higher temperature to create the final look of the piece.

Following these steps on how to bisque fire your pottery will ensure that your piece is strong, durable, and ready for glazing. Now, let’s take a look at how to properly glaze your bisque-fired piece.

Common Mistakes to Avoid

When working with pottery, avoiding common mistakes can save both time and effort while ensuring high-quality results. Here are some pitfalls to steer clear of during the glazing and firing process:

Applying Too Much Glaze

Overloading your piece with glaze can lead to dripping or pooling during firing, which may ruin the design and cause the piece to stick to the kiln shelf. Always apply an even, thin layer for better control. 

Skipping Proper Cleaning

Failing to clean your bisque-fired piece before glazing can result in uneven coverage or defects in the final product. Make sure to dust off any remaining debris and wipe down the piece with a damp sponge before applying glaze.

Ignoring Safety Measures

Glazing and firing can involve hazardous materials and high temperatures, so it is important to take precautions for your own safety. Wear gloves and a mask when handling glazes, and use proper ventilation in your workspace.

Not Calibrating Your Kiln

Kilns need regular maintenance and calibration to ensure accurate firing temperatures. Failing to properly calibrate your kiln can result in under- or over-fired pieces, causing them to crack or break during the process.

Rushing the Drying Process

It can be tempting to rush the drying process in order to get your pieces fired and finished quicker. However, this can ultimately lead to disaster. Drying too quickly can cause cracks or warping in the clay, ruining all of your hard work.

Not Properly Preparing Your Clay

Before beginning any project, it is important to properly prepare your clay by wedging or kneading it. This process helps eliminate air bubbles and ensures a uniform consistency throughout the piece. Skipping this step can result in weak spots or uneven firing.

Frequently Asked Questions

Q1: How Do I Know When My Pottery is Ready for Glazing?

A1: You can check the hardness of your bisque-fired piece by tapping on it with a tool or fingernail. It should make a high-pitched sound and feel hard to the touch. The color should also be light and not appear chalky.

Q2: What Type of Glaze Should I Use?

A2: There are many types of glazes available, including glossy, matte, and textured finishes. It’s important to choose a glaze that is compatible with your clay body and firing temperature. You can also experiment with layering different types of glazes for unique effects.

Q3: How Do I Apply Glaze to My Pottery?

A3: Before applying glaze, make sure your piece is clean and free of any dust or debris. You can apply the glaze using a brush, sponge, or by dipping the piece into a bucket of glaze. It’s important to have a consistent thickness of glaze on your piece to ensure even coverage and prevent any drips or pooling.

Q4: Should I Apply Glaze to the Bottom of My Pottery?

A4: It is not necessary to apply glaze to the bottom of your pottery, as it will be in direct contact with the kiln shelf during firing. However, some potters choose to glaze the bottoms for aesthetic purposes or to prevent any warping that may occur during firing.

Conclusion

Glazing pottery is a crucial step in the ceramic process that enhances both the functionality and aesthetic appeal of your pieces. By understanding the different methods of application, the importance of consistent coverage, and considerations like whether to glaze the bottom of your pottery, you can achieve successful and beautifully finished results.

Experimentation and practice will help refine your techniques, allowing you to bring your creative visions to life with each unique piece. Thanks for reading this article on how to bisque fire.