Mold filling and feeding device (400) and process including using refractory filter cloth (202) to seal a mold line (100), in continuous conveyance, to a multi-stage pressurized filling and feeding device. The mold line (100) consists of vertically parted or horizontally parted green sand molds (101), or an extruded bed of media carrying various types of molds, including green sand, nobake, lost foam, investment casting shells, etc. These molds are bottom or side filled while moving for increased production rates. Feeding under pressure, while moving, is a second operation that improves casting integrity. The process includes a new and more efficient method of treating iron with magnesium for compacted graphite or ductile iron. A stitch (242) of filter cloth (202) holds modifying alloy (630) to the molds (101). A vacuum and pressure controlled column (550) provides consistent flow to thin walled castings, and pressurized feeding for heavy castings. Radiant energy losses are contained in the automatic system. The process and several special purpose machine components make a unified system for hardening liquid (600) such as molten metal in casting of aluminum alloy wheels or other metal castings, and also plastic polymer, rubber tires, etc., or food stuff, as in molded chocolate candy.