Patent ID: 8783302

Claim:
A method of applying an electrically conductive paint to a substrate located in a paint spray booth with an electrically charged paint applicator delivered from a color changer at ground potential, said method comprising the following steps: delivering electrically conductive paint through a first delivery line from said color changer at ground potential to a paint cannister having a reciprocating piston and retracting said piston to receive a predetermined volume of electrically conductive paint in said paint cannister; electrically isolating said color changer from said paint cannister and said electrically conductive paint in said paint canister; providing a second paint delivery line from said paint cannister to the electrically charged paint applicator, said second paint delivery line having a pig being transportable therethrough; and then delivering the electrically conductive paint through the second delivery line from said paint cannister to said electrically charged paint applicator behind said pig by controllably extending said piston to drive a predetermined volume of electrically conductive paint from said paint cannister to said electrically charged paint applicator, thereby electrically charging said electrically conductive paint and applying said electrically conductive paint to the substrate with said color changer electrically isolated from said paint cannister and said electrically conductive paint; and delivering, via a trunk line that connects a first region of said second paint delivery line that is downstream of said pig with a second region of said second paint delivery line that is upstream of said pig, a small amount of purge solvent upstream of said pig prior to transporting said pig through said second paint delivery line, wherein said small amount of solvent has a volume of fifty milliliters or less.