I want to use the main metal from an aluminum can, but it just curls into the shape of the canHow can I straighten out the metal?
Put your food at the focus.
Does this mean you are allowed to use shaped glass? A series of lenses to focus the sun would heat up the food quickly, and also several layers of glass would allow the energy in but not necessarily outFoil on all the edges not directly facing the sun would also allow the heat to reflect internally back on the food as much as possibleUsing these materials I'm assuming they don't expect you to heat the food up very much.
heat it with something like a plumbing torch, but just heat it enough to bend and not to melt.
