Welding question 2

I am struggling to master a simple 115V wire feed welder. I need to repair
a glider trailer. Now, I'm pretty damn good with oxy-acetylene and TIG but
this wire feed thing has me stumped. The rig I borrowed doesn't have an
argon bottle for true MIG welding so I'm using flux core wire.

Of course I RTFM and practised on some scrap until I could run a modest
bead. The big problem is upside-down welding on the bottom of the trailer.
Aside from the need to lie in a shower of hot metal, the results are really
ugly. Any tips?

bildan