The idea of a ruggedized portable soldering station came from having to deal with extension cords when working on large projects in unusual locations. Being built into an old ammo can, it could be carried around easily without fear of taking the case out in the rain. Plus, the ammo can would double as a container for all the extras that go along with soldering, like the solder reel, wick, and other various small tools.

Credit goes to Martin Kumm's design for the building blocks of the heater and the thermocouple amplifier, you can read about his awesome project here: http://www.martin-kumm.de/wiki/doku.php?id=Projects:SMD_Solderstation