The flux core arc welding process and
self-shielding wires can be used when welding outside, or where other
environmental conditions prevent the use of an external shielding gas. In this
process, the outer covering and flux core melt in the heat of the arc, producing
shielding gas and creating a slag covering that protects the weld pool.
This process also creates more smoke and spatter than other types of MIG welding.
A few changes need to be made before beginning. Polarity of the weld circuit
needs to be switched to electrode negative. And since no shielding gas is
required, you should shut off the gas supply. You may opt to remove the nozzle
as well. When you’re finished welding you’ll need to chip or brush the slag
from the weld bead. Make sure you wear safety glasses during this procedure.