Cold Shut or Non-Fill
Incomplete fill of the shell cavity, forming a puzzle-like section in the casting with a positive-negative junction
Indicates that the two metal streams met, but did not merge and completely fill
Likely due to insufficient temperatures or insufficient permeability of the shell
Causes of this defect are evident in the shell, metal and other portions of the process; to cure, R&R recommends taking the following actions:
Shell not permeable enough.
Increase shell permeability cast under controlled atmosphere or vacuum.
Shell/metal was too cold.
Increase temperature of shell/metal.
The mold, shell or metal were too cold.
Increase the temperature of the mold, shell or metal.
Metal was not fluid enough (low metal fluidity).
Increase metal fluidity.
Pour quicker, add more head pressure.
Use Kaowool wrap.
Improper gating (size and structure).
Increase runner and gate size.