Hi guys,
I don't think I phrased my query very well - it wasn't me that was spraying! I appreciate the difference between the G and GH nozzle - don't pretend to fully understand the physics but I appreciate their different forms will modify the plasma
Personally, with our set up, I like run the standard parameters and check the voltage obtained is healthy when ever I come to use the system.
The problem was 2 similar parts sprayed with the same powder in the same week but very different coating hardness an thus in this instance, quality. From my own suspicions and from the advise above I believe this was caused by an unauthorized nozzle swap ie GH to G. I think it would be worth checking our cooling too though.
Needless to say the suspect part has been reworked.
Thanks,
Jim