... The outer box should be larger all around, but it doesn't matter how much bigger, as long as ... box will be visible even after assembly, so if it matters to you, you might want to take more time ... box (black side up), and place your pots on it when cooking. The base is now finished. Building the ... Solar Cooker LidTake the large sheet of cardboard and lay it on top of the base. Trace its outline and ...