[30m] Screwdriver Antenna problem: It was the ground plane!

[Jason Hsu, AA0II]

I attached one long wire radial DIRECTLY to one of the ground screws ON
the bottom of the antenna, and my problem was remedied.  I could
transmit into the antenna WITHOUT having the SWR suddenly go up.  So the
aluminum foil attic insulation ground proved to be an inferior solution
despite the fact that my ohmmeter showed continuity.

Can anyone tell me what I can do to create SOLID bonds between the
antenna grounding screws and my aluminum wire radials?  The #12 copper
wire soldered to pre-tinned copper ribbon taped to a strip of aluminum
foil attic insulation taped to a sheet of aluminum foil attic insulation
taped to a strip of aluminum foil attic insulation taped to aluminum
wire radials doesn't cut it.

The radials are already buried, so I can't move them around.  I can't
use copper, because copper corrodes aluminum.  There are only three
screws on the bottom of the antenna.

Jason Hsu, AA0II