Abstract: A hand-held spray gun for directing a mixture of viscous liquid, such as asphalt, and glass particles onto a substrate surface as an integrated coating. The gun includes an elongated barrel, a spray nozzle at a discharge end of the barrel for creating a discharging spray pattern of liquid particles from a pressurized liquid source, a cutter assembly mounted on the barrel intermediate its ends for receiving a continuous glass roving and cutting such roving into particles for direction into the barrel, a fan mounted adjacent an upstream end of the barrel for directing an air flow through the barrel, and a gasoline-powered engine mounted adjacent the fan for simultaneously driving the fan and cutter assembly.