Well from all the carbon fiber. The stuff I have seen built they bake it in a vacum bag setup. But I am also worried that you dont have enough vacum to form it correctly. And lightweight mdf is hard to find and a tad bit expensive but it available. They also make "bendy board" which is just flexable mdf. Its on page 20 of their online catalog. here is the link
www.selectproducts.com