Abstract: Apparatus mounted on a fixed structure and including a plurality of selectively operable fastener applying guns for securing insulating material to sheet metal without the fastener passing through the sheet metal and while the insulating material and the sheet metal are moving continuously. The apparatus includes a plurality of guns mounted on swinging members and located above a rotating anvil and adjacent to a hold-down roller so that the guns can swing while the fasteners are penetrating the work and move with the work during the time the fasteners are being driven.