[jack neville]

I use whatever works and pieces of railway track are good for pressing over long lengths. But heavy to set up hence the use of my overhead gantry to facilitate positioning of the setup.

As the pressure comes down I just slacken the chain block and then remove the clamps holding the sheet as the curve begins and the pressure holds everything in place. It is crude but effective but for one off things like this it is hard to find engineers either interested or able to do exactly what you need.