Mould structure and its production

Claim 1

METHOD OF PRODUCING AN INEXPENSIVE, STURDY, HIGHLY REFRACTORY MOLD FOR METAL CASTING CONSISTING OF A BACKING BODY AND A FACING WHICH COMPRISES MANUFACTURING THE BACKING BODY FROM A MIXTURE OF INEXPENSIVE REFRACTORY MATERIAL AND A BINDER, SAID BACKING BODY HAVING FORMED THEREIN A POURING SPOUT, PLACING SAID BACKING BODY ABOVE AND SPACED APART FROM A PATTERN, THEREBY DEFINING A SPACE TO BE FILLED WITH THE FACING MATERIAL, POURING THROUGH THE AFORESAID SPOUT INTO THE SAID SPACE BETWEEN THE BACKING BODY AND THE PATTERN A SLURRY COMPRISING A HIGH REFRACTORY MATERIAL AND A BINDER OF A LOWER ALKYL SILICATE, WATER AND A GELLING ACCELERATOR, THEREBY FILLING, THE SAID SPACE, PERMITTING THE SLURRY TO SET BY GELLING, SEPARATING THE PATTERN FROM THE SET SLURRY, AND IGNITING THE SURFACE OF THE GELLED MASS AND ALLOWING THE INTENSE FLAMES RESULTING FROM SAID IGNITION TO BURN UNTIL THE FLAMMABLES ARE CONSUMED.