There is a more elaborate explanation of how I put this together in a blog on my website here: http://watersideworkshop.com/2016/11/06/i-want-to-be-ironman-for-halloween/
When I make a costume, I try to make it functional, cool looking, but also warm so when we are finished, he doesn’t have to hide it with a jacket. All the pieces were printed out and sewn onto a red hoodie one size bigger than he is for the room needed to sew on pieces and hide wires, but also so I can layer warm clothes underneath.
Some of these pieces were heated with a heat gun (hair dryer works) and bent to shape. They were also quickly airbrushed and hand painted with Auto-air paint. It was a fun project that we enjoyed doing.
Safety disclaimer: This costume could be harmful to wear in a car or vehicle due to the stiffness of the plastic with belts, but it easily allows enough movement to take on and off for a car seat.