Chevy Tips and Tech - Welding Basics

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From the September, 2011 issue of Super Chevy / By Patrick Hill / Photography by The Author
Welding can be a scary thing for the novice Chevy builder. While not difficult per se, if you've never used a welder before and your Bow Tie needs some new metal installed, it can be a daunting task.

The nice thing about our modern age (or at least compared to when cars were being restored in the '80s and early '90s) is that welding equipment is cheaper than ever to purchase, and the newer DIY-oriented welders have many automatic features that make the process even easier for a first-timer. Miller Electric's Millermatic series and Lincoln Electric's Power MIG series welders are great examples of user-friendly equipment featuring many automatic functions that make welding easy. Plus, these units come in at under $1,000-a real bargain.

On the electric side of welding, besides the commonly known arc welding, you have MIG (metal inert gas) and TIG (tungsten inert gas) welders. TIG welding is usually reserved for more experienced welders, so we're just going to focus on the MIG side.

MIG welding (also known as gas metal arc welding-GMAW) is a semi-automatic or automatic arc welding process where a spool of wire electrode and a shielding gas are fed through a welding gun. A constant voltage, direct current power source is most commonly used with MIG, but constant current systems, as well as alternating current, can be used. There are four primary methods of metal transfer in MIG, called globular, short-circuiting, spray, and pulsed-spray, each of which has distinct properties and corresponding advantages and limitations.

Developed in the '40s for welding aluminum and other non-ferrous materials, MIG was soon applied to steels because it allowed for lower welding time compared to other processes. The cost of inert gas limited its use with steels until several years later, when the use of semi-inert gases such as carbon dioxide became common. Further developments during the '50s and '60s gave the process more versatility, and as a result it became a highly used industrial process.

Today, MIG is the most common industrial welding process, because of its versatility, speed, and the relative ease of using the process in automated robotic welding. Car companies iuse MIG welding almost exclusively. Unlike welding processes that do not employ a shielding gas, it is rarely used outdoors or in other areas of air volatility. A related process, flux cored arc welding, often does not utilize a shielding gas, instead employing a hollow electrode wire that is filled with flux on the inside.
While working on our Project XS Chevelle and '55 Bel Air at Classic Automotive Restoration Specialists, we took a few minutes to make notes about some stuff that the first-time welder would find helpful before he starts performing surgery on his classic Chevy.

Before getting started on your car, the best thing you can do is get some scrap pieces of metal to play around with and use for getting familiar with the particular welder you've got. Scrap metal can help you hone your skills, experiment with different beading techniques, and allow you to play a bit and get a feel for the whole process of MIG welding.
It's really not that hard, and with some practice and patience, you can learn how to fix your car's metal and feel the satisfaction of doing the job yourself. You may even save a few bucks in the process.



Read more: Chevy Tips and Tech - Welding Basics - Super Chevy Magazine