Cold Shut or Non-Fill

Technical Support

Struggling with a specific casting defect or just need general technical support?

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  • 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.

Pouring practices.

Pour quicker, add more head pressure.

Heat loss.

Use Kaowool wrap.

Non-laminar flow.

Use filter.


Improper gating (size and structure).

Increase runner and gate size.