Wear a respirator, rubber gloves and goggles to prevent possible health complications caused by the glazing ingredients. Mix the ingredients in a well-ventilated area.
Measure out each dry ingredient using either a triple beam scale or a digital scale. No matter what scale you use it must measure accurately to 0.1 grams.
Mix 50.5 percent tenmoku custer feldspar, 12.1 percent whiting, 20.6 percent silica, 5.6 percent EPK kaolin, 2.3 percent barium carbonate, 2.3 percent zinc oxide and 6.6 percent red iron oxide.
Pour water in a bucket. Most ceramic firing glazes are about 50 percent water. For example, 1,000 grams of dry ingredients would typically require 4 cups of water.
Add the dry ingredients to the water a little at a time. Stir the mixture together after you add a little of the ingredients to the water. Continue stirring the water and dry ingredients until the mixture is smooth with no chunks. The glaze should have the same thickness and consistency of cream.
Use the homemade ceramic firing glaze as you would commercial firing glazes.