A reduction of shell mold cracking during solidification and cooling will reduce detrimental metal oxidation and thus improve casting quality and reduce finishing costs. While extensive research has been devoted to the understanding of shell cracking during the autoclave de-waxing cycle, this paper will focus on shell cracking after pouring, during solidification. Engineering approaches were identified to reduce and eliminate the cracking of thin wall, fused silica investment casting shells during solidification and to investigate the effect of cooling rate (position on cooling cart) on metal oxidation. The experimental designs were based on ceramic toughening mechanisms and temperature cycle of shells. The results demonstrated that the combination of a simple “seal” coat after de-waxing and mold cooling rate (position on the cooling cart) had a significant effect on the amount of oxidation present on the final casting.