how would you describe a cold shut?

Andy:

A "cold shut" is an incomplete/improper weld caused by attempting to weld at too low a temperature, but NOT caused by inclusions of foreign matter.

JPH

While forging:This occurs when area being forged say, after fullering, folds over rather than be drawn out flat. the area under the fold is a cold shut.
While welding:This can occur with any electric welding proccess but is common with mig (wire feed) when the temperature is too low or wire too fast or the operator is too slow. The weld at the end or even the edges doesn't fuse to the parts being welded. Instead it pours over like a bead of caulk that is just squeezed out of the tube and allowed to sit on top of the joint instead of smoothing in. This happens a lot in pipe welding: When the weld comes back around to the start and isn't hot enough it will overlap the start rather that fuse into it. The overlapped area is a cold shut

Interesting, to me a cold shut is a foundry term for an incompletely fused casting ie when there is an interrupted pour and the first part is nearly frozen when the second part of the pour occurs. What you call a cold shut in forging I wold call a gall.

Cheers, Bruce