[miket]

The whole point was to make the coroplast foldable so it could easily be pulled apart flattened and stowed away on the vehicle.

I wouldn't remove the inside piece between every single flute but every other flute. So the inside theres a box a space a box a space a box a space etc.The outside is of course smooth. I tried it on some 4mm coroplast and it is still quite stiff across the sheet but now very flexible along the length. The top sheet is supported on the edges by the side sheets. Think of one of those roll up metal security doors small stores use. The hinges make it flexible to roll along the length but the track supports it on the edges. likewise the curved sides would also be supported by the top and bottom sheet.

Now I found with the 4mm coroplast the edges(box space box space) dont interlock with each other unless i crimp the end of the flutes(box) a bit with pliers to narrow them slightly.