Shell cores are ideal for light castings when the weight is critical and to provide increase dimensional controls and surface finish compared to other core production processes.

Shell Core Process

The shell core process is a hot box operation. The cast iron box is heated to operating temperature and resin coated sand is blown into the box. The heat cures  the resin and binds the sand grains creating a shell. The longer the cure, the thicker the shell.

Sand Identification

Core sand is classified based on the American Foundry Society Grain Fineness Number and the resin content. Both the fineness and resin content heavily influence the type of sand used in a specific part. Melling Engineered Aluminum Castings determines sand type based on customer requirements and casting process criteria to ensure a quality core and ultimately a sound casting. 

Assembly Process

Part specific, engineered assembly fixtures designed for repeatability, efficiency, and full communication between components. Cores are produced individually then combined as a “core pack.” Assemblies can utilize internal/external chaplets, hot set glue, solvent paste and compression techniques. The goal of the assembly design and process is to minimize necessary manufacturing aids (i.e. chaplets, etc.). Cores are ready to be placed into molds as one unit after assembly. Utilizing the core assembly process we can reduce the cycle time, the potential for defects in the casting, and reduce the cost of your casting.


  • Redford-16 Semi-automatic Shell Core Machine

  • 2 Redford-43A Shell Core Machines

  • Foundry Automation Dual Station Shell Core Machine

  • HS-22RA Shell Core Machine

Melling AC Foundry

Cores are molded sand that create internal passages to accommodate draft or integrate details that cannot be machined in the casting.