What Is Glaze Firing? Learn About Ceramic Glaze Firing

As previously mentioned, ceramic production involves more than just 2-3 steps. There is another crucial step that requires special understanding and attention: Glaze Firing. This process is carried out after bisque firing and glaze application.

Glaze firing is the process of placing glazed ceramic pieces into a ceramic kiln to melt the glaze, allowing it to fuse with the surface of the piece. This creates a surface with properties specific to each type of glaze, such as a glossy, semi-gloss, or matte finish, which is durable and suitable for use.

Glaze Firing Temperature

The glaze firing temperature is not a single number for all types of ceramics. It depends on the type of clay, the glaze, and the temperature specified by the manufacturer. Generally, it is advisable to check the information for each type of glaze and clay before firing to achieve optimal results and reduce the risk of damage to the pieces.

For larger or thicker pieces, the rate of temperature increase should be carefully controlled, and the firing time extended appropriately. This helps reduce the risk of cracking or damage from rapid temperature changes.

Another tool used to monitor firing is the Pyrometric Cone, which assesses the actual heatwork received by the piece, considering both temperature and duration of heat exposure. Therefore, when firing with cones, it is important to refer to the specific cone type and appropriate recommendations, and not to rigidly set a fixed time after the cone falls for all cases.

Things to Know Before Glaze Firing Your Pieces

An important aspect to consider in ceramic glaze firing is the proper preparation and arrangement of pieces inside the kiln to prevent damage during firing.

• Wipe the glaze off the bottom of the pieces thoroughly.
• Maintain adequate spacing between pieces.
• Prevent glaze from running onto kiln shelves by using Kiln Wash.
• For some types, stilts may be used to elevate the pieces and prevent the glaze from directly contacting the kiln floor.
• Allow the kiln to cool down slowly and naturally.

Clean the Kiln Every Time

Before placing pieces into the ceramic kiln, always inspect and clean the interior of the kiln to remove any clay debris, grit, dust, or other foreign matter that might fall onto the pieces during firing.

Even tiny particles can create imperfections on the glazed surface, affecting the aesthetics, quality, and value of the finished piece.

Therefore, glaze firing is another crucial step that ceramic artists should not overlook. Selecting the appropriate temperature for the type of clay and glaze, properly preparing the pieces, as well as arranging them and maintaining the kiln, all contribute to the quality of the final product.

Paying attention to details even before firing will help minimize damage and increase the chances of producing beautiful and high-quality ceramic pieces.