The annealing process of the precision casting ensures the precision casting shell, shell is the basic function of gloss and precise casting.Shell needs to have good process performance, which can accurately reproduce the casting shape, ensure the accuracy of the size.Surface is bright and clean, and there is plenty of room temperature and high temperature strength and the stiffness was required. Precision casting type of the use of four kinds of methods, general parts after stripping local has soft false place can use a trowel row loose tooling then pounded.Two wall intersection place have the damaged part can trowel stick on gravel, sand and then touch the gap to make again.Chunks of sand was brought out to brush on mud water to repair, the area is large, but not deep grooves should dig out some fill again.