A method and apparatus for controlling the dispersion of molten metal in a mold cavity is disclosed, the control facilitated by a localized densification of foam in a lost foam casting operation for producing metal castings, wherein the filling of regions of the mold cavity which do not lend themselves to castability is maximized, an amount of backfill and casting defects are minimized, and a flow pattern of molten metal and material properties of the resulting casting are optimized.