Abstract: A printed circuit processing apparatus includes a modular tank arrangement with each of the tanks receiving a printed circuit board to be processed on edge, or in other words vertically, and which guides the printed circuit board through the tank for processing without leaving marks or "tracks" on the sides of the board. The boards are driven by rollers on which the lower edges of the boards rest. The boards are held vertically through the use of a plurality of vertically spaced longitudinally extending wires. Spray nozzles are positioned on opposite sides of the boards and are simultaneously operated to generally equalize the pressure on the opposite sides of the board. The spray nozzles contain the necessary solutions for processing the boards, and the guide wires are small enough so that they don't leave any areas of the board unprocessed, nor do they leave "tracks". The modular tanks permit one or several operations in a continuous path with connecting sections between the modular tanks.