Abstract: A system for applying a uniform band of liquid primer material to the marginal edge surfaces of glazing units upon which a plastic frame or gasket member is to be molded in place. A family of interchangeable applicator tips is provided for use with a dispensing device adapted to provide an on-demand supply of primer material to the tip in use. The different applicator tips of the family have configurations particularly adapted to applying bands of primer material along selected peripheral margins of a sheet member. Each is of a composite construction including a relatively rigid base member covered by a soft absorbent body for contacting and transferring to the sheet surface the layer of primer material. The tips are readily attachable to and removable from the primer material dispensing device.