 The process is versatile and can be performed with relatively inexpensive equipment , making it well suited to shop jobs and field work . An operator can become reasonably proficient with a modest amount of training and can achieve mastery with experience . Weld times are rather slow , since the consumable electrodes must be frequently replaced and because slag , the residue from the flux , must be chipped away after welding . Furthermore , the process is generally limited to welding ferrous materials , though special electrodes have made possible the welding of cast iron , nickel , aluminum , copper , and other metals . 
