PVC or Rubber Raft/Air Lift Bag Design and Engineering

Looking for an engineer with experience in welded pvc or rubber materials construction. Looking to build rafts and air lift bags using materials such as Elvaloy, Polyurethane, Chlorosulfonated polyethylene ( Hypalon ), Butyl,
Nitrile/Nitrylon etc. Must have both design and manufacturing experience with these materials and proven experience working with them.