Spot or stripe sprayed onto a test plate with the gun held still for a moment or passed once, so the operator can see the shape and centering of the deposit. A round, centered footprint means good powder injection and alignment; a comet tail, offset or double peak points to wrong carrier gas, a damaged injector or a misaligned gun. Footprint width is also used to choose the index between passes.
Shoot a footprint on the scrap plate, I think the injector got bumped when you changed hardware.
Also heard as
- spray spot
- spray pattern
- spot test
Related terms
Carrier gas
The gas stream, usually argon, that carries powder from the feeder through the hose into the spray jet.
Pass
One sweep of the gun across the area being coated; the coating is built up pass by pass.
Plume
The visible jet of hot gas and glowing particles streaming from the spray gun toward the part.
Shoot
Booth verb for spraying a coating onto a part or coupon.