“Holy Pressure Vessels Batman!”
Don’t do this at home. Gas pressure is not necessarily your friend. Take this article for example. This guy was killed by the air pressure alone. 140 pounds per square inch across your chest (approximately 12″x12″ on me = 144 square inches) will come out to be 10 tons of force on some important parts of your body.
So, if you’re retreading tires, please be careful.