A Plaster Spray Gun, 1951 The introduction of plastering pumps and spray guns in the 1950s accelerated the use of lightweight aggregated construction. Joseph M. McNulty's 1951 invention could spray on a thick coat of plaster-an inch or more. The patent was assigned to the E Z On Corporation. The Nailable Metal Stud, 1953 In 1953, Jacob M. Gwynne patented "nailable metal structural members" to replace "wooden studs, joints, rafters and the like." The system had flanges "formed to provide nailing areas" for "firm engagement with lateral surfaces." 77