Methods and apparatus for producing display quality glass sheets are provided in which the batch materials for making the sheets are melted in a furnace whose glass-engaging surfaces comprise zirconia (ZrO2). By using molybdenum electrodes, instead of the conventional tin electrodes, to electrically heat the molten glass, the wear rate per unit area of the furnace's glass-engaging, zirconia-containing surfaces are reduced by more than 50%, thus reducing zirconia levels (solid+dissolved) in the finished glass by at least a similar amount. As a consequence of this reduction, rejection rates of finished glass sheets are lowered, which is of particular value in the production of glass sheets of large dimensions, as desired by display manufacturers and other users of such sheets.