Water Spotting
Whitish spots on a pre-treated part where minerals in the water have been deposited.

Weather Resistance
Capacity of a coating surface to resist the effects of weathering (UV light and water erosion)

Weld Splatter
Beads of metal or flux left after welding.

Wrap
A characteristic of a powder coating in electrostatic application to seek out and adhere to areas of the substrate not in direct line of sight.