Stegmeier Slip-N-Join Lumber is a reusable forming material that is designed to provide excellent performance on radius forming projects.  Slip-N-Join Lumber, unlike plywood or masonite, is reusable, making it more economical with each job. A light form oil is necessary for the first two uses.  It is light weight and easy to bend into a consistent radius. Slip-N-Join Lumber will not warp or swell from water absorption. Sections can be connected with included couplers.