Both glaze firing and bisque firing are crucial stages in ceramic production, each serving a distinct purpose. While both involve heating the clay, there is a notable difference in temperature between glaze firing and bisque firing.
Bisque Firing
Bisque firing is the initial firing stage, where raw clay is heated to a temperature of around 1,800 to 1,900 degrees Fahrenheit (982 to 1,037 degrees Celsius). This firing removes water and organic materials from the clay, making it more rigid and less porous.
Glaze Firing
Glaze firing, also known as high firing, is the final firing stage. During glaze firing, the kiln temperature is raised to a higher range, typically between 2,200 and 2,400 degrees Fahrenheit (1,204 to 1,316 degrees Celsius). This firing causes the glaze materials to melt and fuse, creating a glass-like surface coating on the pottery.
Temperature Comparison
As seen from the temperature ranges, glaze firing is indeed hotter than bisque firing. The higher temperatures reached during glaze firing are necessary to achieve the desired finish and functionality of the glazed ceramic piece.
Conclusion
Glaze firing is conducted at a higher temperature compared to bisque firing. Both firing stages are integral to the ceramic process, with bisque firing preparing the clay for glazing and glaze firing creating the final aesthetic and functional qualities of the piece.