My Dart Swinger Project!

The 4 Key Points of Welding:

Heat
Angle
Distance
Speed (of travel, and/or wire speed)

Coordinate all of these together and you can get perfect looking welds. Gravity plays a part too pulling on the molten puddle as you are moving along.

As Gearhed73 stated above, clean up the axle tubes before welding . . get the rust off. It will be a stronger more pure weld and won't spatter so much.