Arc Welding 101: Hands-off MIG education

Q: I recently bought a gas metal arc welding (GMAW) machine, and I’ve also just completed a beginner’s welding course at the local college. Unfortunately, the basics don’t explain enough about the controls, such as voltage, wire speed, and stickout, and how they affect the weld penetration, height, and travel speed. Do you know of any reasonably detailed books or videos on the subject? I plan to weld box tubing together, and I’d like complete penetration because I’m grinding the beads flat, but I’d like to achieve an even flatter bead profile to begin with. I’ve learned how to adjust the knobs for that nice, clean buzzing sound, and I get things to stick together nicely, but I’m not sure what to dial in for the penetration and bead profile I’m looking for.

A: Your story is all too typical of many welder training programs. In a manufacturing environment, with a continual focus on process control, it baffles me that many welders don’t have a good understanding of the basics when it comes to controlling the weld process. Hands-on welding often is the focus of an employer-based or vocational school GMAW class. But hands-on welding without process knowledge is a whole lot of just spinning your rollers (wheels … get it? I’m funny!). You need to be able to answer two important questions:

1. What mode of weld metal transfer does this joint call for?
2. Which weld settings (volts, wire feed speed) will produce that mode?

The first place I would start is www.weldreality.com. There you’ll find a book titled Manual and Robotic Gas Metal Arc Welding, by Ed Craig. This book has been the backbone for all my GMAW training. Also, most of the big equipment manufacturers have free, downloadable process information. You’ve taken a class that has given you the hands-on knowledge for GMAW; now you need to spend a little time increasing your process knowledge with a good book.

By the way, instead of grinding those welds to make your project look like one continuous piece, why not buff those welds to show price in your workmanship?