Cool.
I had the opposite problem with some stuff that was a bit too thin. I used it for making retracting lanyards for use on / round water.
1] Wind a long coil along the length of some sort of rod. Knitting needle, wooden spoon handle .etc [pick a width appropriate to how thick a wire you've got]. Secure the ends.
2] Bung the lot into a pan of boiling water, and carry on boiling for a couple of mins.
3] Quick swill in cold water
4] Remove forming rod and find you have now set a long coil in the line with a tendency to want to contract. Improve the strength of that tendency massively by working your way along the coil with your hands rolling each twist so it turns back on itself. When you're done you'll find it wants to contract much more strongly than it did before
5] Add crimps to hold a loop you form at either end for attaching your whatever. Fishing rod to kayak, forceps to PFD,..