Measure specific gravity

Specific gravity tells you how much water and how many solids are present in your glaze. It changes over time due to factors such as water evaporation, but also through the glazing process itself. That is why it is important to measure the specific gravity regularly before dipping or pouring. With brush-on glazes, the specific gravity usually remains fairly stable.

First, stir the glaze thoroughly. It should be completely mixed. Then take a large 60 ml syringe. Fill the tip of the syringe with glaze, making sure there are no air bubbles. Weigh the syringe with the filled tip and reset the scale to zero. Next, draw exactly 50 ml of glaze into the syringe. Work carefully and avoid air bubbles. Weigh the syringe again. The displayed weight is the weight of 50 ml of glaze. Record the value to at least one decimal place. Divide the weight in grams by the volume in millilitres. The resulting number is the specific gravity.

Compare your result with the value indicated on the SOGO glaze label. Is your value higher? Then the glaze contains too little water and you should carefully add a small amount of water. Is the value lower? Then your glaze contains too much water. Allow the glaze to settle, then remove some of the water with a syringe. Measure the specific gravity again and repeat until you reach the correct value.