Bonding of inert particles

Claim 1

A METHOD ENABLING THE USE OF WOODEN MOLDS AND REUSE OF THE MOLDS WITHIN MINUTES IN THE MANUFACTURE OF STRONG SHAPED RESINOUS ARTICLES, SAID METHOD CONSISTING ESSENTIALLY OF THE STEPS OF (1) MOLDING TO A SELF-SUSTAINING WET SHAPE UNDER MODERATE PRESSURE A MOLDABLE AGGREGATE OF MINUTE PARTICLES EACH COATE WITH A SOLUTION OF A BINDER IN A VOLATILE LIQUID VEHICLE, AND WHERE THE PARTICLES ARE NONPOROUS, THE AVERAGE PARTICLE SIZE LYING BETWEEN 60 AND 400 MESH, AND WHERE THE NONPOROUS PARTICLES ARE EQUIVALENT IN SPECIFIC GRAVITY TO SAND, THE AGGREGATE INCLUDING 0.4 TO 2 PARTS BINDER AND ONE TO 8 PARTS VOLATILE LIQUID VEHICLE PER 100 PARTS BY WEIGHT OF PARTICLES, THE PROPORTIONS IN ANY CASE BEING SO SELECTED THAT THE AGGREGATE IS NONSTICKY AND HOLDS ITS SHAPE WHEN FASHIONED WITH THE FINGER; (2) DRYING THE SHAPE TO A HARD, HANDLEABLE, CRACK-FREE, UNIFORMLY POROUS STATE; (3) SATURATING THE DRIED SHAPE WITH A HEAT-CURABLE LIQUID RESIN COMPOSITION WHICH IS SUBSTANTIALLY FREE FROM VOLATILE SOLVENT AND IN WHICH THE BINDER IS SUBSTANTIALLY INSOLUBLE; AND (4) THEN CURING SAID LIQUID RESIN COMPOSITION TO A DENSE RESINOUS STATE, SAID PARTICLES BEING INERT TOWARD SAID BINDER, SAID VEHICLE AND SAID LIQUID RESIN COMPOSITION.