on the comment of stick welding having better penetration than MIG. It is true that 6010 or 6011 has the best penetration, but there are very few "amatuer" welders with the skill and experience to make good welds with this rod. This is also true of most people who think a few passes with a MIG gun makes them an expert. While it is possible to make a good looking weld with MIG, lots of times there will be lack of penetration on one side of the weld, and without experience, it is not easy to see! When you have the experience(I have over 12,000 hrs of welding MIG) a wire welder will handle anything from 20 gauge to 3/4" plate. There is no easy way to be an expert welder. It, like most things takes a lot of experience, and if you are lucky, someone to show you what is right and wrong.