Mold surface treatment process and mold

摘要

A mold comprising a cavity for defining the shape of a casting and a mold body for forming said cavity, comprising: a mold body formed of an ordinary temperature setting resin or thermosetting resin and casting sand, said mold body having a surface layer portion on the surfaces thereof including depressions, said depressions in the surface layer portion being filled up with at least one porous powdered material selected from the group consisting of hydrous magnesium silicate clay mineral, activated carbon and activated alumina, thereby providing the mold body with smooth surfaces whereby said mold generates less amount of material such as gums which cause defective castings during casting since molten metal is restrained from intruding into the walls of said mold.