Author: Jordan Powell Photos: Jordan Powell
Welding is undoubtedly one of the core fundamentals of fabricating. In every Masterpiece In Metal we have ever published, some sort of welding had been done to the vehicle, whether it was by the means of metal inert gas (MIG) or tungsten inert gas (TIG). And while the process of melting metals together can be done in the most basic, unappealing way, welding is a serious art form and many strive to lay down the perfect bead. Though it’s rather likely that it will take some time before you will be able to stack some photo worthy dimes, don’t let that discourage you from taking one of the necessary steps to becoming a successful fabricator. So grab your welding gear and some scrap metal, and let Troy Johnson from the Fab School in Riverside, California, help you become a MIG welding guru.
WHAT YOU’LL NEED:
Before you power up your MIG welder, you’re going to need some basic gear, like a welding helmet and gloves, wire brush, and some MIG pliers. Welding helmets can range in price depending on features like an auto-darkening glass, like the one pictured here, or a more moderate, standard glass. Welding gloves will keep your hands from burning up, a wire brush will help clean your material and welds, and MIG pliers provide numerous useful functions. You should also wear a long sleeved shirt, or buy some welding sleeves from your local hardware store. Not only will it save you from splatter hitting your bare arm, it will also save you from the dreaded welding sunburn.
CLEAN YOUR MATERIAL:
If you’re working with some dirty material, it’s crucial that you take the necessary steps to clean it so you don’t end up with porosity in your welds. Those tiny cavities not only look horrible, they will actually contaminate and weaken your weld. So to save you from this headache, grab some Scotch-Brite pads, a wire brush or some acetone to remove any debris or paint that may be on your welding surface.
DIALING IN THE SETTINGS:
Before you can start welding, you need to make the appropriate settings for your voltage and wire speed, as this will be dependent on the thickness of your material. One way of finding the correct settings is actually to do some test welds. On the piece of material pictured here, you’ll see that our welds on the far left were too hot for the thickness of this metal, so we lowered our voltage and wire speed. In the middle, our settings were too cold, and had poor penetration. After adjusting our voltage and wire speed somewhere in between the two, the welds on the far right were spot on. There was good penetration and they had a slight convex shape.
When dealing with tubes that have a bunch of joints coming together, like a roll cage, it’s important to get a full 360-degree weld around each tube. To do so, you’re going to have to start by welding one tube all the way around, and then add the next tube to do the same.
As you can see here, our settings were too hot and we blew straight through our tubing.
If you’re fortunate enough to have a MIG welder that has an auto-set feature on it, like this Millermatic, the guesswork can be taken out of the equation. Simply select the material size and hit the auto-set button.
INSPECT YOUR WELDS:
After you’re done welding, you should always inspect and clean your welds. If you look closely at the piece of material pictured here, you’ll see that on the far left a slight breeze came into the shop and caused our weld to bubble up. Now, if you have some welds that look like what’s on the right, you might need to turn on, or change, your welding gas. It’s not the end of the world if this happens, but you do need to make sure you grind out the contaminated weld and start over.
CLEAN YOUR TIP:
Another important factor in MIG welding is the contact tip. After hours of welding, the contact tip can have weld spatter built up on it, or it might have lost its shape. Although you can simply clean off the tip with your MIG pliers, you should replace the contact tip if its shape has changed.
LET ‘ER RIP:
Now that you know some of the basics to MIG welding, it’s time to start laying down some beads. Before you do so, though, you should come up with a plan of attack, meaning that you should map your weld. If you’re welding from point A to point B, how are your hands going to travel that path? You also want to be as steady as you can be, so make sure you’re holding the MIG gun with two hands and let ’er rip!
Source: The Fab School (951) 782-0567 www.thefabschool.com