Investment casting shell quality is a very important factor in producing top-notch, reliable parts. There are numerous potential causes of less-than-optimal shells that are controllable by the right foundry staff and processes. Shells are made by repeatedly dipping wax patterns in a special ceramic slurry, which is then heated to produce molds for the desired parts. Inferior shells can result in inferior parts. Top-quality shells require careful management of slurry composition, drying time, ambient temperatures, humidity, air flows, and other factors. There are many other quality control considerations in the investment casting process, but shell quality is a good place to start.
