Method of joining shell molds

Claim 1

THE PROCESS OF MAKING A COMPOSITE SHELL MOLD WHICH COMPRISES PREPARING AN INVESTMENT COMPOSITION CONTAINING PREDOMINANTLY REFRACTORY PARTICLES WITH AT MOST ABOUT 3% OF A THERMOSETTING RESIN CONTENT AND AT MOST ABOUT 5% OF A HIGH TEMPERATURE BINDER CONTENT, DEPOSITING A LAYER OF SAID INVESTMENT COMPOSITION ON A PLURALITY OF HEATED METAL PATTERNS MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 200* AND 500*C. TO CAUSE THE DEPOSITED RESIN CONTENT TO BIND TOGETHER AT LEAST A THICKNESS OF SAID LAYERS INTO BOUND SHELL LAYER SECTIONS WHICH WHEN ASSEMBLED ALONG MATING JUNCTION SURFACES WILL DEFINE A MOLD CAVITY OF A METAL OBJECT TO BE CAST, REMOVING ANY EXCESS OF DEPOSITED COMPOSITION CONTENT NOT ADHERING TO THE INDIVIDUAL LAYER SECTIONS SO FORMED, THEREAFTER ASSEMBLING THE INDIVIDUAL SHELL LAYER SECTIONS AND JOINING THEM ALONG THEIR MATING JUNCTION SURFACES INTO A COMPOSITE SHELL MOLD STRUCTURE, THEREAFTER HEATING THE ASSEMBLED COMPOSITE SHELL MOLD STRUCTURE OT A TEMPERATURE IN EXCESS OF 500*C. FOR CAUSING SAID HIGH TEMPERATURE BINDER CONTENT TO BECOME EFFECTIVE AND CAUSING THE REFRACTORY PARTICLES OF SAID INDIVIDUAL SHELL LAYER SECTIONS TO BECOME BOUND TO EACH OTHER AND ALSO TO ESTABLISH A JUNCTION BOND ALONG THEIR MATING JUNCTION SURFACES AND THEREBY JOINING THE MATING SHELL LAYER SECTIONS INTO AN INTEGRAL MOLD STRUCTURE.