ACT II student Chris is seen welding aluminum in lab. Auto Collision students must learn to weld steel with a MIG welder and aluminum with this 220 volt Firepower welder. Welding is a skill that must be mastered to be a capable auto body technician. Students learn how welders work, terms used in welding and welding theory by doing textbook assignments and then go to the lab to practice stitch, spot, plug and continuous welds.