A method of applying a viscous material to a fastener comprises aligning a nozzle relative to the fastener by engaging an aligner with the fastener. Engaging the aligner with the fastener comprises positioning the aligner over the fastener and advancing a biasing tube toward the fastener to establish contact between the aligner and a structure to partially retract the aligner into the biasing tube until a plurality of surfaces of the aligner contacts one or more outer surfaces of the fastener. A flexible wall of a dispenser bellows is deflected by expanding a pressure-application device, which is configured to apply pressure on the flexible wall of the dispenser bellows, wherein the dispenser bellows is in fluid communication with the nozzle. The viscous material is expelled from the dispenser bellows responsive to deforming the flexible wall.