"I could work 6 meters from a wire with a tuner. "
You could but don't bother.
I'd start with a minimum of a rotatable dipole. Home Depot sells some aluminum C-channel that's heavy enough to build a rotatable 6m dipole and you could rotate it with a TV rotator.
I built a Moxon out of that Home Depot aluminum.http://n3ox.net/projects/sixmoxon/
If you really can't rotate it, try a halo or fixed dipole or something.
Whatever you do, build a *resonant* dedicated 6m antenna that's a good match to coax and use good coax.
Feedline and tuner losses will kill your signal on 6m, and dedicated single band antennas are small and easy to build.