I'm wiring in a rotary phase converter and am almost finished. But I don't want to run a separate piece of conduit to the subpanel. I only have to pull a single 6 ga. neutral wire through the existing conduit and it isn't that long, maybe 5', but it's metal flex and I'm having a heck of a time (read: It ain't happenin') doing it because of the 90 deg. angle and the other wires in there. There's plenty of room but just not making it. Tried to thread a piece of 12 ga. solid conductor through first to use it to attach to the 6 ga. and pull it on through but I can't even get the 12 ga. through. I'm trying not to go buy a fish wire just for this one job. Any suggestions?