Abstract: A resin application apparatus used in the production of oriented strand board has a rotary atomizer supported within a drum for containing and tumbling wood flakes. A spinning cup is rotatably supported by a housing of the atomizer, with a gap formed between an outer surface of the cup and the housing. A supply line provides resin to the spinning cup for atomization thereof and coating of the tumbling wood flakes. A passageway is formed in the housing terminating in an outlet proximate the spinning cup. Solvent is flowed through the passageway and out of the outlet, sweeping away any accumulated material in the gap and on the spinning cup and housing. The cleaning operation is performed simultaneous with the flow and atomization of the resin, whereby the resin application process continues without interruption.