G2 Stucco: How Does it Rate? Wax to Metal in 8

摘要

Typical investment of wax patterns requires a few days. Some pattern complexities and shell/ drying conditions require longer times, while a few are shorter. Every foundry however has a customer who inquires about receiving their casting in-hand within days. The G2 stucco system invented by McGuire and Hellstrom has provided this interesting capability to foundries nearly regardless of slurry system used. Shell property testing and extensive customer tests of two G2 stucco offerings now support consideration of this unique rapid shelling option. G2A is Minco’s current production version and G2B is an experimental stucco blend undergoing testing. This paper will summarize and discuss various shell strength test conditions including bend and burst tests. Also shell permeability, thermal expansion curves and loaded creep results will be reviewed. Actual shell dryness comparison of standard shell versus a G2 stucco shell has been made by TPM in Houston TX. Unfortunately this was not quite complete by the paper deadline. This data will be made available in the presentation at the annual meeting.