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Apparatus and methods for differential pressure, counter gravity, casting of metal in a gas-permeable mold having a vertical passage with a lower open end for introducing molten metal into its mold cavity means. A crucible is provided for holding molten metal with its surface positioned beneath the

Apparatus and methods for differential pressure, counter gravity, casting of metal in a gas-permeable mold having a vertical passage with a lower open end for introducing molten metal into its mold cavity means. A crucible is provided for holding molten metal with its surface positioned beneath the mold. The crucible and the mold are relatively movable toward and away from one another for introducing molten metal into the lower open end of the mold, and pressure means is provided for applying a differential pressure to the mold and crucible to cause molten metal to fill the mold cavity means through the vertical passage. A rigid, permanently crimpable fill pipe is sealingly connected to the lower open end of the vertical mold passage with its lower end extending vertically downwardly toward the crucible. Fill pipe crimping means is positioned between the mold and crucible for selectively permanently crimping the fill pipe to close it, after filling of the mold cavity means, to prevent reverse flow of molten metal from the mold to the crucible as the mold and fill pipe are moved relatively away from the crucible.

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A method of casting in a gas permeable mold, comprising the steps of: providing a gas permeable mold having a vertical passage with a lower open end for introducing molten metal into mold cavity means therein providing a mold support having a lower opening positioned beneath said mold passage lower

A method of casting in a gas permeable mold, comprising the steps of: providing a gas permeable mold having a vertical passage with a lower open end for introducing molten metal into mold cavity means therein providing a mold support having a lower opening positioned beneath said mold passage lower open end providing a crucible for holding molten metal with its surface positioned beneath said mold support providing a rigid, permanently crimpable metal fill pipe having a radially outwardly extending upper flange removeably sealingly interposed between and surrounding said mold passage lower open end and said mold support lower opening with its lower end extending vertically downwardly therefrom toward said crucible relatively moving said mold and fill pipe toward said crucible to move the lower end of said fill pipe beneath the surface of molten metal in said crucible to introduce molten metal from said crucible into the lower end of said fill pipe applying a differential pressure to said mold and crucible to cause said molten metal to fill said mold cavity means through said fill pipe, crimping said fill pipe to close it after filling of said mold cavity means to prevent reverse flow of molten metal from said mold cavity means to said crucible as said mold and fill pipe are moved relatively away from said crucible, and finally removing said fill pipe from said mold and support.