Can't see the weld when welding ???
Flux core welding produces smoke in the process of covering the weld with slag to keep the atmosphere and impurities out of the weld till it cools.
The smoke produced at the weld is limiting your ability to see and control the molten puddle.
Another advantage to gas shielded welding, you can much easier see the molten weld puddle.
Also for those that are talking start stop stitch welding, this works best with gas shield welding, no flux to roll down and create porosity in the weld when you stop and start.
