Stop Chasing Perfect Castings—Start with Perfect Sprues You've nailed the ceramic shell. The alloy's pure. Pour temp? Dead on.Then—crack—a casting comes out flawed. We've all been there. And more often than not, the weak link wasn't the pour or the shell. It was hiding in the wax room: a sprue that looked "close enough" but wasn't. Hand-rolling sprues has its...