For some, it may seem inconceivable, but a few equipment manufacturers produce machines capable of both wet-mix and dry-mix shotcrete spraying without converting the equipment. The method these machines use is known as the wet-thin stream method of conveyance.The design is based on the rotor-style dry process machine. The rotors, however, are designed for the wet process as well. This is achieved by equipping the machine with a low-proï¬le rotor with large-diameter ports, which allows the wet-mix to drop into the ports and be pneumatically conveyed through the hose to the nozzle. The hoppers are fastened with rubber mounts and equipped with vibrators that assist the material in flowing into the rotor.