he correct arc length varies with each electrode and application. As a good starting point, arc length should not exceed the diameter of the metal portion (core) of the electrode. Holding the electrode too closely decreases welding voltage. This creates an erratic arc that may extinguish itself or cause the rod to freeze, as well as produces a weld bead with a high crown. Excessively long arcs (too much voltage) produce spatter, low deposition rates, undercuts and maybe porosity.

Many beginners weld with too long of an arc, so they produce rough beads with lots of spatter. A little practice will show you that a tight, controlled arc length improves bead appearance, creates a narrower bead and minimizes spatter.