Embodiments of the present invention relate to automatic sanding hopper systems and methods for supplying sand to a tap hole in a furnace. The automatic sanding hopper system may automatically open a chimney door to provide access to a furnace through a chimney hole. A hopper assembly in the sanding hopper system may automatically move to a position in which a plunger may automatically actuate to clear or clean out the chimney hole. The hopper assembly may thereafter automatically move to a position in which a sand dispenser delivers sand through the chimney hole, into the furnace, and into the tap hole in the furnace. A sensor device may determine whether or not the tap hole is properly filled with sand. The hopper assembly may automatically retract and the chimney door may automatically close to begin another steelmaking heat.