The method is called Hot moulding. There are some pictures under kayaks, gallery and pictures from workshop. As Pete guesed the heating shapes the wood and hardens the glue. The same way as when you are using steam. But hot moulding is not common among amatures. Cold moulding is more common among amatures. It is done similar but no heat is added. And you use 4" widh strips of veneers layed across in thre layers. You can use a regular strong back as mould just add some support along it cover the mould with some plastic sheet and use staples to keep the veneers together.