Abstract: A pair of horizontally disposed nozzles above a horizontally disposed seal edge surface for coating a frit slurry in a closed pattern on the surface are moved in opposite directions from an abutting, mutually blocking position until the nozzles again come into sealing abutment at a second point above the surface. During the travel of the nozzles, a frit slurry is discharged therefrom at a constant rate and is deposited in a uniform stripe on the seal edge surface. Just before the nozzles abut at the end of the coating operation, the flow of frit slurry from one of them is terminated. This permits the frit slurry from the second nozzle to make a tapered overlay of the frit slurry from the earlier cut off nozzle without forming a bump or extra width at the joint. A rectangular gear generally conforming to the shape of the seal edge surface to be coated is employed to drive the nozzles at a substantially linear speed along the seal edge surface.