Build an Arc Welder from Microwave Ovens: Part 3 June 30, 2009 by rickety 6 Comments The Story So Far Paul obtained his microwave ovens, wired the garage for 220 volts, and extracted the first transformer. In this segment he replaces the old secondary windings with new, thicker wire. One side of the secondary winding was sawed off with a hacksaw. The secondary windings were in so tight they had to be knocked out. Tearing out a few windings loosened the rest. The secondary is completely removed. Using short lengths of 6 gauge wire as guides. The completed secondary consists of 11 feet of 6 gauge wire wound in 11 turns. Related Articles Build a Microwave Transformer Homemade Stick/Arc Welder Learn from the experts.