When using Motsenbocker Lift Off #4 in a pressure washer it is recommended that this application only be used in a natural porous surface such as unpainted brick, concrete or slump stone. The affected area should be sprayed with Motsenbocker Lift Off #4 out of a trigger pump or can be applied with a tank sprayer when large areas are affected with the graffiti. Once the affected areas have been sprayed and allowed to sit for two or three minutes then a pressure washer can be used to remove the graffiti. It is recommended that a pressure washer of at least 2000 PCI with a ten degree spray tip be used. It is not necessary to use although in some instances this can be helpful, after the Motsenbocker Lift Off has been sprayed in but before the pressure washer is used to rinse. When rinsing we recommended that you start at the bottom and working its way up vertically to remove the graffiti. This is so the water doesn’t wash away the product while it’s activated on the graffiti.