Sodium Sulfate (Na₂SO₄)
Sodium sulfate (Na₂SO₄), historically known as "Glauber's salt", is a chemical compound that has both decorative and technical applications in ceramics. As a flux, sodium sulfate lowers the melting point of glazes, facilitating vitrification and improving adhesion to the clay body. It is especially useful in low-temperature glazes, where it helps to create shiny, well-fused surfaces.
In experimental and decorative techniques, sodium sulfate is used to generate unique visual effects. When interacting with the surface of the pieces, it can produce crackle textures, color gradients and reactive patterns. It is also used in salt firing processes, where the vapors released during firing react with the ceramic surface to create rustic and textured finishes.
Its high solubility in water facilitates its application as a liquid solution, either by dipping, painting or spraying. However, its reactive nature requires careful handling, as excessive amounts can cause problems such as run-off or glaze destabilization.Interesting Fact
Sodium sulfate not only has a legacy in ceramics, but has also been used for centuries in the chemical and pharmaceutical industry. Today, it is a key ingredient in detergents.Helpful Tip
Use sodium sulfate in small quantities and test sample pieces to evaluate its impact on the glaze or decoration. Work in a ventilated area and wear personal protective equipment, as dust can be irritating. Be sure to store this compound in airtight containers to avoid moisture absorption.
