If you haven't fabricated anything for your truck, but would like to, you can easily learn the most basic skill necessary -- MIG welding -- to build almost anything for your ride. We teamed up with one of the biggest names in the welding industry, Miller Electric, to prove that anyone can learn how to weld. We really mean anyone, since our own associate editor, Mike Alexander, was the guinea pig for this article and is pictured throughout the learning process. This article will give you the knowledge needed to safely operate a MIG welder and the basic how-tos of laying down a good weld. Once you have the basics down, with tons of practice, the sky is the limit and so is the level to which you can customize your own truck.
A wire-feed MIG welder outfit consists of the welder itself and several consumable items. These consumables include the electrode, welding wire, and shielding gas. A MIG welder is capable of welding ferrous metals such as steel, aluminum, and stainless steel, depending on what type of shielding gas you use and the diameter and the type of the weld wire. Since our trucks are built from steel, we'll concentrate our efforts toward making good welds on steel.
The MIG process welds steel together by heating the metal with an electric arc. The arc is generated between the electrode in the welding gun and the metal workpiece. This arc is shielded from contaminants in the atmosphere by the shielding gas. The most common shielding gas readily available at welding supply houses is a mixture of 75 percent argon and 25 percent CO2. This mix helps produce welds with little slag and excellent penetration. The wire we'll use in conjunction with the shielding gas will have a steel core with a copper coating and diameter of 0.035 inch. This wire will be suitable for welding steel with a thickness between 1/6 and 3/8 inch. When we weld sheetmetal, we can switch electrodes in our welding gun, then switch to a smaller-diameter wire such as 0.023 inch.
MIG-welding is one of the easiest welding processes to learn as well as the most inexpensive. For Part I of the welding series, we're going to focus on the basic MIG setup and how our first attempts at welding turned out. Then, we're going to practice our technique, and as time goes on, we'll show you what we learned and how our welding has improved.
The argon/CO2 shield-gas mixture is regulated to 25 psi with this regulator. The bottle is turned off between welding sessions. | 
In this article, we'll be welding 3/16-inch mild steel plate, which is used for all Silver Star Custom notches. This 0.035-inch wire is suitable for this application and was inserted into the Millermatic 210 wire-feed welder. |
After the wire is fed into the driver roller, the welder is turned on, and the trigger is pulled on the gun. The drive roll activates and feeds the wire into the liner of the gun. Drive tension is adjusted until the wire feeds smoothly through the gun without "bird nesting." The wire is then cut off 3/16 inch away from the tip of the gun. It's a good idea to cut the small section of old wire off the end before you begin welding because it will lessen the initial pop from the welder at the beginning of each weld. | 
Before you begin welding, you must first ground the welder to a metal work surface the part can sit on, or connect the ground clamp directly to the part you'll be welding. |
Once the welder is set up properly, grab some scrap steel to practice welding on. We decided to use a set of notches from Silver Star Customs to illustrate our learning curve. In this picture, we jumped right in without much practice and welded up one of the notches. The gun should be positioned at a 45-degree angle, with the contact tip approximately 3/8 inch away from the surface of the steel. Use one hand to hold the gun, and the other hand to steady it. | 
It's important that this gap and angle be maintained as the gun is moved along the surface of the metal. To begin welding, the trigger on the gun is pulled, which simultaneously turns on the shielding gas, wire feed, and voltage. If the gun is held steady enough, you'll see a small puddle of weld form on the metal, which you can either drag toward you or push away. Pushing the weld along the steel will typically yield a less-desirable weld, with less heat penetration than dragging the weld puddle along the steel. |
On the inside cover of all Miller MIG welders, you'll find a handy chart. This will tell you what settings the wire feed and voltage the welder should be set to for each metal type, depending on what kind of shielding gas and wire diameter you're using. Follow the setting instructions, and you'll have a better chance at producing a good weld. | 
The front of the welder is where you'll find the on/off switch and controls. In the upper-left-hand corner, there's a dial marked wire speed. This dial controls the rate at which wire is fed into the gun. The dial on the right is marked voltage, and it controls the amount of voltage coming from the welder. The more voltage applied, the hotter the arc coming out of the gun will be, and the thicker the weld will penetrate into the material. There is a direct correlation between voltage and wire speed: The hotter the weld, the quicker the wire must be fed into the puddle. |
Once the welder is set up properly, grab some scrap steel to practice welding on. We decided to use a set of notches from Silver Star Customs to illustrate our learning curve. In this picture, we jumped right in without much practice and welded up one of the notches. The gun should be positioned at a 45-degree angle, with the contact tip approximately 3/8 inch away from the surface of the steel. Use one hand to hold the gun, and the other hand to steady it. It's important that this gap and angle be maintained as the gun is moved along the surface of the metal. To begin welding, the trigger on the gun is pulled, which simultaneously turns on the shielding gas, wire feed, and voltage. If the gun is held steady enough, you'll see a small puddle of weld form on the metal, which you can either drag toward you or push away. Pushing the weld along the steel will typically yield a less-desirable weld, with less heat penetration than dragging the weld puddle along the steel. | 
Your first few attempts at MIG-welding will most likely not yield a very effective or good-looking weld. This is Mike's first attempt, and it's not too pretty. You'll find that a steady hand is one of the most important parts of making a good weld. In this photo, we see that although the welder is set correctly and the weld is penetrating the metal (look at the heat marks around the weld area), the weld is not good. Without much practice of the proper technique, Mike moved too slow and didn't spread the curlicues far enough apart, so the weld piled on top of itself. |
As Mike finished up one of the notches, he became a little more aware of a steady hand and the placement of the weld. Here is a much better weld. As you can see, there is an equal amount of heat penetration throughout the weld, and the weld is equally distributed. A good technique for distributing the puddle across both parts being welded is to make curlicues or small letter C welds as you go. We found that this will give a much more desirable stacked-dime look to the weld. Aside from looking at the weld, you can tell a good weld from a bad weld by the way it sounds. You'll hear a continuous buzzing noise when making a good weld. A bad weld will make popping noises and a lot of sparks and sound very inconsistent. | 
What does a bad weld look like and why does it happen? This photo illustrates what happens to a weld when insufficient voltage is supplied from the welder. The arc is not hot enough to penetrate the steel adequately and as such the weld has a tall, fat appearance, with little or no heat penetration marking around the weld. Turning the voltage up to the recommended level will cure this situation. |
Here's a good example of what happens when you move the gun too quickly across the work area. Moving the gun too quickly breaks up the puddle. You'll know you're screwing up by all the sparks and prominent popping noises you'll hear. | 
Moving the gun too slowly will yield a weld that is too wide and sloppy-looking, and will put too much heat into the work piece. |
After completely welding up both notches, Mike's welds show definite signs of improvement. Now that he's getting the technique down, all it will take is some practice to produce a desirable weld every time. Don't miss Part II to check on Mike's progress and see if he can weld some more stuff up. | 
Once you've mastered MIG-welding steel with your welder, you can move onto other materials such as aluminum. Certain models of welders, including the Millermatic 210, offer optional spool guns, which have their own wire supplies built into the gun. Switch out the bottle of argon/CO2-mix shield gas for straight argon, and you can easily MIG-weld aluminum together. That's another story altogether, though, and something we will later. |