Inventors: Chester, Victor;
Assignee: General Porcelain Mfg. Co. (Trenton, NJ)
Primary Examiner: Padgett; Benjamin R.
Assistant Examiner: Barr; J. L.
Attorney, Agent or Firm: Kane; John J., Zoda; Frederick A., Sperry; Albert
A composition of matter utilized by particular method for forming an electrically conductive glaze upon the outer surface of a ceramic mold form wherein the combination includes approximately 33 percent soda feldspar, approximately 20 percent flint, approximately 9 percent calcium carbonate, approximately 1 to 2 percent ball clay, approximately 2 percent kaolin, approximately 7 percent zinc oxide and approximately 27 percent black iron oxide, all percentages being taken by weight, the method including the addition of an amount of flocculant such as 20 percent magnesium sulfate solution or deflocculant such as sodium tetrapyrophosphate or sodium silicate to control the viscosity of the solution and thereby control the thickness of the layer formed upon the external surface of the ceramic mold form, including the spraying or dipping of the mold form in the resulting solution for coating thereof as well as the firing of the coated ceramic mold form in a furnace or approximately 2200 to 2300 degrees Fahrenheit for approximately a 30 hour cycle. |
Heat Accumulators 
