Molding apparatus for rapid transfer of molten resin or pitch in an infiltration molding process. The apparatus includes e.g. an extruder (4) for melting and conveying a resin or pitch and a mold (10) arranged so that resin or pitch is conveyed to a mold insert cavity (19) within the mold. The mold insert contains an internal protrusion such as a locating ring (25) for positioning a porous body (1, 18) within the mold insert cavity in a position that brings about unidirectional flow of the molten resin or pitch through the porous body. Also, rapid resin or pitch infiltration molding process that includes injecting a high melting point, high viscosity, molten resin or pitch into the mold to effect a unidirectional impregnation of a heated preform via a pressure gradient in the mold.