Although welding with Argon does make it easier to make nicer welds, flux-core wire can be used to make surprisingly good welds, regardless of what anyone thinks or says. Just like anything, setup is the key, if you can't weld without gas, you can't weld with it any better. Although I'm primarily a machinist, one of my duties is to do balancing as well. I was called out of the shop to balance a 1000hp electric motor a while back, and when it came time to weld the balance weights on the motor's cooling fan, I had to use the 110v, flux core welder they had at the location. It was a Lincoln and looked exactly like yours. After a couple practice beads on some scrap, I was amazed at how well it worked. The thing made nice, solid, spatter-free welds that couldn't have been done any better had I been using a sheiding gas. If I was to give you some advice, I'd say crank up the amps a bit and move slower. Good welds on sheetmetal should be on the verge of blowing through. Your kinda look like they're sitting on top. But then again, you are welding temporary bracing in an old Mustang not welding the solid rocket booster tanks on the space shuttle. Function is more important than beauty.
