in actuality, heat guns are not idiot proof, or you can take this as a proof that i am an idiot. i actually distorted a plastic pen's barrel with a heat gun because i was not cognizant of its non-local distortion until it was too late. the section was far from being loosened, but because the majority of the heat went to the barrel area, i ended up losing its perfect reflection properties.

yes, i may have given up too easily, and i guess this heat gun technique has a learning curve, but why risk it if i know flame will work every single time?