Also wanted to mention that I'd probably go with PEC-AL-PEC 1" if I had to purchase loop material again. Like this one:
You get slightly more than 1" (OD) of aluminum pipe inside plastic material. It's probably still light. I made loops from 7/8" (OD) HVAC soft copper pipe and 5/8" (OD) HVAC soft aluminum pipe. All of these can be formed by hand but 7/8" copper pipe is noticeably heavy! I won't be surprised if 1" PEC-AL-PEC will be even lighter than 5/8" (OD) aluminum.
Regards,
Simon
KM6MUL
