I have 8ga wire. Stranded copper. Used some on a 10m vertical, doubled over. Worked good then experimented with aluminum cable company coax about an inch in diameter. After a storm last April a neighbor and I waited weeks for them to pick it up after the new stuff went up. Never did and a good amount is still there, hanging in small trees and shrubbery along a street.
Work about as good as the 8ga copper. I expected a huge difference but can barely tell a difference. The copper might actually be better but if you're in a situation were you only have ONE, to work with ... then do what you do and get out the tools.
[edit] I didn't use the coax as a coax. I used it as elements. Unshielded aluminum, porous plastic interior with a solid 10ga center conductor.
[editx2] I say porous but it's kind of a tight cell bubbly interior, white in color, easy to melt with a torch in case you want to flatten one end.