Corona guns typically run from about 30 to 100 kV. Higher kV improves first-pass transfer on open surfaces and lets the gun sit farther from the part, but it adds free ions, worsens Faraday cage effect and speeds back ionization. Operators lower the kV for recesses and recoats and watch the microamp reading, which shows how much current is actually flowing to the part.
Knock the kV down to 40 on the recoat, at full power it's just starring the surface.
Also heard as
- kilovolts
- voltage
Related terms
Corona gun
A powder gun that charges particles with a high-voltage electrode at the tip, the most common gun type.
Free ions
Charged air molecules from a corona electrode that never attach to powder but still land on the part.
Back ionization
Tiny electrical discharges inside an overcharged powder layer that repel new powder and pit the finish.
Transfer efficiency
The share of sprayed powder that ends up on the part rather than in the booth.