Each piece of rebar is held in place by a copper wire. The wire is run through some drilled holes around the rebar. The rebar is actually soldered to the copper wire. To solder the wire to the rebar, I first notched the rebar with an angle grinder. I then used some plumbing flux to clean the surface and a MAPP gas torch to heat it. I actually used some rosin core, leaded electronics solder to make the joint. It actually wetted pretty easily.
Another wire runs all the way around the bucket. Each of the rebar wires is twisted around the main wire. I twisted a bunch of excess wire at the end of the loop to create a thick enough terminal to easily clamp onto.