Lost-foam casting

After the coating dries, the cluster is placed into a flask and backed up with un-bonded sand which is compacted using a vibration table.

Secondly it controls permeability, which allows the gas created by the vaporized foam pattern to escape through the coating and into the sand.

As the foam is of low density, the waste gas produced by this is relatively small and can escape through mold permeability, as for the usual outgassing control.

It is also dimensionally accurate, maintains an excellent surface finish, requires no draft, and has no parting lines so no flash is formed.

Lost foam is generally more economical than investment casting because it involves fewer steps.

[5] Lost-foam casting was invented in the early fifties by Canadian sculptor Armand Vaillancourt.

Public recognition of the benefits of LFC was made by General Motors in the mid 1980s when it announced its new car line, Saturn, would utilize LFC for production of all engine blocks, cylinder heads, crankshafts, differential carriers, and transmission cases.