Salt glaze
Salt glazing is a traditional ceramic firing technique that involves introducing salt (usually sodium chloride) into the kiln during the final stages of firing, when the pieces have already reached high temperatures, above 1200°C. Upon contact with the hot, humid kiln environment, the salt volatilizes and chemically reacts with the silica present on the surface of the ceramic, forming a glaze layer rich in sodium carbonate. This process creates a glossy, glazed finish that not only enhances the colors and details of the piece, but also provides a waterproof and durable resistance.
The process requires precise control of temperature and salt exposure time to achieve the perfect balance between gloss and the desired rough texture. In addition, uniform salt distribution within the kiln is crucial to avoid defects and ensure homogeneous glaze coverage.
Salt glazing is known for its unique and varied effects, such as crackle, where the glazed surface develops small cracks that add character and visual depth to the pieces. In addition, firing conditions can generate unpredictable color variations, making each piece unique.Interesting Fact
Although salt glazing was popularized in Germany during the 16th century, its origins can be traced back to ancient techniques used in various European and Asian cultures. For example, in Italy and Spain, they also experimented with salt as a glazing agent to improve the durability and finish of their ceramic pieces, adapting the technique to their local styles and traditions.Helpful Tip
When using salt glaze, make sure you have adequate ventilation in your kiln to handle the corrosive gases generated during salt volatilization. Also, experiment with the amount of salt and the timing of its introduction to control the thickness and uniformity of the glaze.
