Environmental affect on plasma sprayed coatings

[nshepher]

Hello,

I have tried reaching out to several experts in the industry about what affect the environment of the spray booth has on the microstructure of coatings and it seems that nobody can give me a straight answer. In practice it seems that we start having porosity and oxide issues when the temperature is low (below 40 degrees F) or the humidity is high (80% relative or higher) if we are pulling air from the outside environment instead of conditioned shop air.

My question is does anybody have parameters for temperature, humidity, dew point, etc. that they consider a "no spray" range if using unconditioned outside air?

If your shop is using outside air for ventilation are you conditioning it or not?