Said of a gun whose settings put too much heat into the particles or substrate: high power, extra hydrogen, short standoff or slow traverse. Running hot raises oxide content, decarburizes carbides, vaporizes fines and overheats parts. Running cold, with low power or long standoff, gives unmelts, low deposition efficiency and higher porosity, and a good parameter set sits between the two.
Carbide's coming out brittle and the W2C peak is up on XRD, we're running hot, back the oxygen off.
Also heard as
- running cold
- hot
- cold
Related terms
Unmelts
Lab shorthand for particles that hit the surface without fully melting and kept their round shape.
Oxides
Thin oxide films formed on metal particles in flight, showing as dark stringers between splats.
Cook
Booth slang for overheating a part during spraying, usually from slow traverse, short standoff or no pauses.
Particle diagnostics
Sensors that measure the temperature, speed and size of particles in flight to monitor the spray process.