PPSh-41: Upper Receiver
Since this piece hinges and supports lots of other parts, I decided to try to form this from a single piece of plastic. I cut a piece of wood to match the INSIDE of the receiver and using the heat gun, wrapped the plastic around the wood.
Unfortunately, because of the length of the piece I couldn't keep a uniform level of heat on the plastic to keep the bends even. Not only is the receiver uneven and lumpy, but it turned out too wide.
My second rule of building (the first being "measure twice, cut once") is "don't be afraid to do it over". This time I cut out the sides of the receiver as individual panels and join them together like a box. I glued in a thin strip on the inside joints for support.
I glued the sides on to the top piece (a "u" shape) and then glued in a barrel support and the muzzle end.
Before I glued the bottom, I painted the inside as it would be next to impossible to paint it when completed.
A little putty, sanding and blading the edges to get the "bend metal" round edges that I tried to get with the first attempt.