Re: Working with copper
Copper work hardens. Wrought copper fittings are already somewhat hard ffrom the cold work done while making them.
The good news is copper anneals easily. Grab your torch, and heat one of those couplings up to red hot. Toss the hot fitting in a bucket of water, then you could flatten it with your fingers.
You can anneal copper repeatedly as you work it. It is not uncommon to have multiple anneal steps when forming things that are deep drawn from copper sheet.
No need to work the copper while hot for a little project like that.