a universal reusable system is provided for molding concrete or other settable fluids for use in building construction . in the subject system , apertured composite plastic panels and frames , prestressed by the presence of an array of removable and interchangeable oversized plastic plugs , are positioned and held in place by a framing system which utilizes a combination of apertured strips used as base guides and both vertical and horizontal channels , as well as dowels and plugs . the use of apertured panels and framing system provides for a reusable assembly whose dimensions can be readily set on site for each application and whose rectilinearity is maintained either by the dowel - aperture combination or by a combination of oversized plugs in adjacent members to be joined and connectors therebetween .