Reforming plastic - experiment one

I've had an idea for a while to reshape plastic with heat. Specifically 200 liter barrels!

The first experiment has been to pop a drinks bottle in the oven. ;)

I put a dash of water in it and spun up the oven to maybe 150C. It made a little steam pressure as the temperture rose.  Fairly soon the bottom of the bottle made a rather nice balloon! :)

I pulled it out just in time before it burst. It's thin but pretty strong.

The experiment has confirmed a few thoughts in my mind;

1. it's doable
2. the vessel needs containment otherwise the expansion runs away at the weakest point.

Next step... not sure yet. ;)