Hi Mr Davis,
with the heat gun it would really depend on the type and power of it, i wouldnt use a LPG shrink wrap gun as all you would have after a few seconds is a pile of useless smelly plastic.
and a high powered electric one would just blow holes in the work if you were not carefull probally similar to trying to weld with an OXY cutter lol
and a low powered electric gun wouldnt do much at all i know guys that work in a bumper bar repair place and they use a filler rod [scrap bumper bar cut into strips] and a 40 watt soldering iron with a wide tip or chisel tip they are properly called dont use a pointy tip for this as you leave more scratches than you would like to deal with
hope you understand my ramblings.
