Patent ID: 8122583

Claim:
A method comprising: casting a metal in a mold cavity, the mold comprising a shell and a casting core partially embedded in the shell; removing the shell and core from the metal, the removing leaving at least one opening in a surface of the metal, the at least one opening formed by the casting core; masking with a non-liquid mask to form a skirt; filling the opening with a sacrificial material, the filling comprising, after the masking, an at least partial immersing in a vessel containing a liquid form of the material, wherein: during the immersing, the skirt allows an exposed portion of the metal to lie below a surface level of the liquid; one or more openings of the at least one opening are within the skirt; the immersing is sufficient to provide an up-flow of the liquid out of said one or more openings within the skirt responsive to introduction through another one or more others of the at least one opening outside the skirt; machining the metal and the sacrificial material at the at least one opening; and after the machining, removing a remainder of the sacrificial material.