Any idea how to build a 12V iron box???

I'm coordinating a community upraising project in Kenya, and we're doing green energie workshop as well as re-use of plastic bags by fusing them so we're looking for a green way to do it... 12V Iron box would be perfect...
Thx for your consideration.

You could make a small metal box Make circles of Nichome wire add a Aluminium piece ontop Inside another metal box add a 12 v car battery or any current and it will heat up very hot and very quickly .

(this is how i made an oven for my shed)
How about using solar to heat a metal bar ?