Ask a professional welder or anyone who has the slightest interest in welding what the most common type of welding is, and you can expect to hear the same answer: It’s MIG welding.
Some people agree that MIG welding is the easiest among all types of welding. But let’s not take other people’s word for it. After all, it’s better to provide an opinion after experiencing it first hand.
So today, we are going to unravel essential information about MIG welding, such as how it works, its benefits, tools and equipment, and tips on how you can achieve high-quality welds.
What Is MIG Welding
MIG or Metal Inert Gas welding is an electric arc welding process that uses a thin filler wire electrode. The wire enables a strong bond between two metal workpieces.
Also known as Gas Metal Arc Welding (GMAW), MIG welding forms an arc around the metal weld pool during welding. The electric arc is created by the inert gas and the wire electrode deposited to the weldment.
What Is a MIG Welder
A MIG welder like the Forney Easy Weld is both a shielding gas medium and an automatic or semi-automatic wire feeding welding machine that contains a rotating motor where you can install the spool.
This motor equipment continually rotates and feeds the consumable wire electrode to the welding gun or torch during the entire welding process.
How Does MIG Welder Work
After triggering the MIG welder, the wire is automatically inserted into the wire feeder inside the welding gun by the spool inside the machine until it comes out at the contact tip of the nozzle.
This wire is constantly fed into the nozzle and melted by direct electric current to create the filler metal during welding.
The electric current forms an arc between the wire electrode and the metal sheet piece that enables the metal pieces to reach the melting point.
Shielding gas, composed of argon and CO2, is released alongside the formation of an electric arc to protect the weld pool or molten metal from reacting to water and oxygen.
This shielding gas is siphoned by the MIG welder from a high-pressure cylinder and goes through a gas diffuser, then released out through the nozzle.
All these processes happen in a cyclical manner where the electrical current flows from the MIG welder to energize the machine, to the torch to create the electric arc and shielding gas, then to the metal workpiece, and lastly back to the welding machine.
How to Set Up a MIG Welder
As you have seen, there are several types of equipment that you simultaneously use:
· power supply
· welding machine
· gas tank
Setting them up perfectly is the key to good welds. And that is what we are here to do.
Power Supply
The power supply provides a constant voltage during the welding process. The voltage is generally a direct current electrode positive (DCEP).
Ensure that the transformers and rectifiers function in their optimal state without power overloading to maintain constant line voltage, essential in stabilizing the electric arc. To do so, clip the ground clamp to the base metal to complete the machine’s circuit.
Welding Machine
Ensure the spool roller works can feed the wire to the welding torch out to the nozzle of the welding torch.
Check the tension nut that holds the spool in place without unraveling or jamming. Keep the tension in the correct amount for a smooth wire feeding.
For a list of optimal MIG Welders, perfect for people on a budget, here is a comprehensive blog that lists down all the MIG welders under $1000.
Wire Electrode
As a rule of thumb, always match the wire electrode to the base metal you are welding. In other words, you should use a stainless steel wire for a stainless workpiece and a mild steel wire for mild steel base metal. You get the gist.
Additionally, choose the wire based on the welding position you will use, the thickness of the base metal, and the number of passes you plan to make.
Gas Tank
Generally, MIG welding is gas-shielded, so a cylinder gas tank should always be behind your back. For the shielding gas to come out at an appropriate amount, turn the handwheel of the cylinder gradually until the pressure gauge shows 1000 PSI, the minimum requirement to weld.
After which, adjust the regulator by turning it clockwise to release the gas slowly. Ensure the gauge is only releasing 10-15 cubic feet of gas per hour (CFH).
Welding Gun
The welding gun is where most of your attention should be during the whole welding process. As the trigger, the welding gun automatically controls the flow of electricity and motor drive that feeds the wire during welding.
Ensure the wire is inside the nozzle before welding to avoid exposure to contaminants before you even start welding.
Benefits of a MIG Welder
After setting up the MIG welder, you can now weld your metals away and experience the following benefits first hand:
Fast yet controllable welding speed
Thanks to the constant voltage and gas-shielding control, welding two metals with MIG is faster than other welding methods like gas tungsten arc welding or TIG. The easy adjustment of wire feed speed also allows welders to operate MIG for various applications.
High-quality weld results
Despite the fast welding capability, the resulting weld still stays clean and high-quality due to the absence of flux and slag, which requires additional working hours during slag removal.
The semi-automatic or automatic process of MIG also ensures low material spatter and results in minimal wastage of welding alloy.
Convenient long single-pass application
The continuous wire feeding does not require you to change the welding wire from time to time. MIG allows you to use a sizable spool of wire electrodes, which lets you weld for long, single passes.
Deep penetration into the weld
MIG is known for its high penetration rate. So whether you are working on thick metals and other hard materials, you can achieve solid and deep joint welds.
Tips on How to Achieve Quality Welds
Even with the complete and correct MIG welder installation, reaping all those benefits can sometimes be hard to accomplish. Fortunately, there are a few tricks and tips, if coupled with patience and concentration, that can help in your attempt to achieve the perfect weld.
Clean the workpiece
Cleanliness matters in welding, too. So always make sure to remove debris, grime, and paint on your base metal, as these can weaken the resulting weld.
Also, keep your tools clean all the time, especially when you’re thinking of welding for the consequent days. Become a fussy welder when it comes to base metal preparation.
Hold the gun in the right distance and angle
Place the welding gun around 3/8 inch away from the base metal to transfuse the right amount of heat and protection during welding. Holding it any further than 3/8 inch decreases the heat and protection coverage.
Remember to position the gun at a 15-degree angle and move towards the welding direction. And travel at a steady speed to achieve a clean weld bead. Do not change pace if you do not want to have an oversized weld bead that may have holes in it.
Change the contact tips of the gun
Lastly, always replace the contact tip after a few heavy welds. Worn-out contact tips can cause welding results to deteriorate over time, as it affects the heat transference and formation of the welding arc between the welding gun and the base metal.
Last Words
You now know how MIG welder works and how you can achieve a good quality weldment. But still, if you’re new to the craft, do not expect to get perfectly shaped weld beads and aesthetically pleasing results immediately.
We all start somewhere, even the experts. You only have to start at the right time and place using the right guide like this article.
