I found an IKEA dresser in the garbage downstairs. I found a roll of duct tape. So I naturally thought: "hey, I can make the sliding door from this!" :)

Starting out with the measurements of where the sliding door will go I made three ribs that define the curve:


Which I then covered with strips of the back of the dresser to form the mould.

I then covered it with 4 alternating layers of roving and mat fiberglass:


Now it's time to sand it to get the curve just right and build it up to the desired 4mm thickness by additional layers of fiberglass.