A system for applying liquid coating such as paint to a surface including a spindle-shaped roller cover having painting fabric permanently attached to the roller cover body and that can match the nap of the paint fabric used in a conventional roller used to paint flat surfaces; and a paint pan adapter which enables the user to use the corner-painting roller cover in a conventional paint pan as a reservoir for holding the coating material. The adapter is provided with a V-shaped grille which has a plurality of holes. The grille is elongated like a trough. Part of the length of the grille is submerged in the coating material and part is not. The trough along which the roller cover roles makes it possible for the roller cover to pick up paint from the reservoir of the paint pan and to remove excess coating material from the roller cover and return it top the reservoir.