Good weld:
Notice the good penetration into the base material, flat bead profile, appropriate bead width and good tie-in at the toes of the weld (the edges where the weld metal meets the base metal).
Voltage too high:
Too much voltage is marked by poor arc control, inconsistent penetration and a turbulent weld pool that fails to consistently penetrate the base material.
Voltage too low:
Too little voltage results in poor arc starts, control and penetration. It also causes excessive spatter, a convex bead profile and poor tie-in at the toes of the weld.
Travel speed too fast:
A narrow, convex bead with inadequate tie-in at the toes of the weld, insufficient penetration and an inconsistent weld bead are caused by traveling too fast.
Travel speed too slow:
Traveling too slow introduces too much heat into the weld, resulting in an excessively wide weld bead and poor penetration. On thinner material it may also cause burn-through.
Wire feed speed/amperage too high:
Setting the wire feed speed or amperage too high (depending on what type of machine you're using) can cause poor arc starts, and lead to an excessively wide weld bead, burn-through, excessive spatter and poor penetration.
Wire feed speed/amperage too low:
A narrow, oftentimes convex bead with poor tie-in at the toes of the weld marks insufficient amperage.
No shielding gas:
A lack of or inadequate shielding gas is easily identified by the porosity and pinholes in the face and interior of the weld.
