Abstract: The present invention deals with the continuous metal exchange for workpieces such as a printed circuit board which can take place in a plating tank. The workpieces are conveyorized for continuous horizontal transport into and out of a plating tank. Opposite ends of the tank are provided with slots to receive and discharge the workpieces which are sealed, in the instance illustrated, by opposed rollers or an open slot of small area to prevent leakage in excess of the pump capacity. The workpieces are suspended at their upper portion by a non-conductive hanger, the lower portion of which is rendered conductive. When the workpiece enters the plating tank the conductive portion of the hanger suspending the workpiece from the conveyor, makes contact to energize bus bars thereby converting the workpiece to a cathode (or anode if metal is to be removed). A plating solution is inside of the tank and provided with anodes or cathodes energized for metal exchange.