There are a few different types of welding (depending on who you ask, there’s up to nine), but one of the most common is MIG welding. It’s one of the easiest types of welding to learn, it’s versatile, and it’s simple to set up, but what exactly is MIG welding, and why is it so good?
With competitive price and timely delivery, Jinertai sincerely hope to be your supplier and partner.
Metal Inert Gas (MIG) welding is an arc welding process in which a solid wire electrode is continuously fed through a welding gun into a weld pool. An arc is formed between the wire electrode and base metal, melting the base material while consumable filler wire is deposited, creating the weld.
At the same time, a shielding gas is fed through the welding torch to protect the weld from outside contaminants.
MIG welding is also known as Gas Metal Arc Welding (GMAW).
The MIG welding process is relatively straightforward, and most of it is automated too.
MIG welding is always done on direct current (DC), which means that the current only runs in one direction. Like a battery, it requires a completed electrical circuit to work. All the components of the welder work together to form this circuit.
First, a wire spool is loaded into the machine. This wire is fed through the driver rollers, into the torch liner and out of the contact tip and nozzle. The wire will start feeding continuously when the torch trigger/button is pressed and stop when it’s released.
Pressing the torch trigger will also start the gas (if it’s needed), which is fed through the nozzle to shield the weld.
The wire plays two parts: heat source and the filler material. When the wire passes through the copper contact tip, it becomes electrically charged with the welding current. The wire comes out of the torch and touches the base metal, creating an arc between the two.
That’s the first half of the electric circuit formed.
The arc melts both metals, depositing filler metal into the molten base metal to form a weld. There are several ways filler metal can be transferred from the torch into the base. Your normal MIG welding transfers metal via the short circuit mode.
Check out our post on short circuit welding and the other modes of metal transfer to learn more.
The final piece of the puzzle is the earth clamp. Without it, your machine won’t arc. You can still pull the trigger and feed the wire through your torch, but all you’ll end up with is wasted wire.
The earth clamp completes the electric circuit that runs from the machine, through the torch, into the base metal, and then back up the earth clamp to the machine.
On top of that, getting a proper grounding is important because a bad earth can cause several issues, including burnback and a wandering arc.
MIG welding is considered a semi-automatic process. The wire feeding is automatic, but the torch movement is still manual, making it semi-auto.
There are only two settings on MIG dedicated machines: voltage and wire feed speed.
The voltage determines how much heat is in the weld. Turning it up or down will adjust how much welding current is added to the weld.
The wire feed speed determines how much wire per minute is added to the weld. The more wire that’s added, the cooler the weld will be, and vice versa.
Your voltage and wire feed speed generally work in harmony together. If you turn your wire feeding to the max but leave your volts too low, the wire won’t burn. You need enough heat to melt the wire, but not so much heat that it gets sprayed everywhere except in the weld.
What you want to set them to depends on a few things. The metal thickness, the metal type, filler wire thickness, weld position and joint type will all impact the settings.
If you’re not sure where to start, almost every UNIMIG MIG welder comes with a Setup Guide on the inside of the machine’s door. It provides recommended settings for different metal types, metal thicknesses and wire sizes as a starting point. It also includes the gas flow and polarity recommended for each application.
Getting the polarity right is pretty important, as it impacts the quality of the weld. The wrong polarity will leave you with excessive spatter, an uncontrollable arc and poor penetration.
Gas MIG welding runs on an electrode positive polarity. That means the current is positively charged and runs from the negative to the positive. It’s most commonly referred to as reverse polarity or DCEP (Direct Current Electrode Positive).
To set up a UNIMIG welder for DCEP, plug the polarity cable in the positive (+) panel mount and the earth clamp into the negative (-) panel mount.
In our case, the polarity cable acts as the torch because all of our MIG torches come with a Euro quick-connect plug. If your machine doesn’t have a Euro connection, it’ll plug directly into the dinse connecter.
Keep in mind, only gas MIG uses DCEP. The polarity is flipped to DCEN (Direct Current Electrode Negative) if you’re looking to weld with flux-cored (gasless) MIG wire.
That means you’ll plug your torch/polarity cable into the negative (-) panel mount and your earth clamp into the positive (+) panel mount.
MIG welding is one of the more versatile when it comes to the different materials that it can be used on. These metals include:
There are two things to consider when picking your filler wire. Making sure the base and filler metals match and getting the right size.
You want your wire metal and its grade to be as close a match to your parent metal as possible. If you’re welding with mild steel, you’ll need mild steel wire. If you were welding aluminium, you could choose or or another grade wire, depending on your parent metal.
Filler wires of the same metal as your base metal will work even if the grades aren’t an exact match. Don’t worry if you’re not sure what grade your metal is; just match the metals.
The other thing to consider is how thick your wire is. If you’re working with sheet metal, you’re not going to want filler wire that’s 1mm thick. Your wire should be thin enough that it’ll melt but thick enough that there’s enough metal deposited to form a proper join.
A good all-around wire size is 0.8mm. You can drop down to 0.6mm for very thin metal or go up to 0.9mm for thicker applications.
Shielding gas is used to protect the weld from outside contaminants. The gas you can use will vary depending on the type of metal you’re welding. Different gases also have different effects on the weld.
The most common (and generally best) shielding gas you can use for mild and stainless steel is a 75% argon/25% CO2 mix. It helps stabilise the arc and deepen penetration while shielding the weld. For aluminium welding, pure argon gas is needed for shielding.
These aren’t the only two that are available, though. For a full list of all the different gases you can use, check out our post on choosing a MIG gas.
MIG welding can be used on a wide range of metals across a wide range of thicknesses. It’s also one of the fastest ways to weld. These factors combined make it the most commonly used welding method across several industries.
Some of the most common uses of MIG include:
There are a lot of things that make MIG a great choice, not just the fact that it’s easy to learn (though that is one of them!).
While it might be the most popular type of welding, that doesn’t mean there aren’t a few downsides to MIG.
In summary, MIG welding is fast, efficient, simple to set up, easy to learn and used for almost everything. If you’re just getting into the world of welding, it’s the perfect place to start.
Gas metal arc welding (“GMAW”) is an arc welding process that uses a consumable wire electrode and shielding gas, which a welding gun feeds to the joint.
An electrical arc between the wire and base metal generates heat that melts. Shielding gas protects the molten weld pool from harmful atmospheric gasses.
For more Mig Welding Wireinformation, please contact us. We will provide professional answers.
GMAW most commonly uses a constant voltage, direct current power source, but constant current systems and alternating current are usable.
This article explains the basics of the MIG welding process, when to apply it, the necessary equipment, GMAW career opportunities, and the pros and cons of MIG welding.
A MIG welder automatically feeds an electrically charged, solid wire into the weld joint at a set speed, and the supplied gas shields the molten pool.
The power source inside the welder energizes the wire, creating and driving the arc.
GMAW always uses a direct current electrode positive (“DCEP”) polarity. That means the ground clamp attaches to the negative terminal, and the MIG torch attaches to the positive terminal.
Attaching the ground clamp to the welded piece and pulling the MIG torch trigger to feed the wire into the joint creates an arc. The arc happens as the wire contacts the grounded metal, which closes and shorts the electrical circuit.
The arc quickly generates heat, and the wire at the tip melts, as does a thin part of the base metal. But the wire feeder continually pushes a solid wire into the joint, which creates another short circuit.
Shorting the circuit and melting the tip occurs many times per second, and it’s responsible for spatter, sparks, and the well-known, unique MIG sizzling sound. It sounds like bacon frying in a pan.
Note that the wire acts as an electrode and filler metal material with the MIG process. It’s required to create an arc and deposit metal into the joint. So, it’s impossible to MIG weld without filler material.
The short circuit transfer method is the most commonly used. But there are four primary methods of metal transfer possible with GMAW:
The metal transfer mode depends on the wire feed speed, the voltage setting, and the shielding gas.
Read more on transfer modes here.
The minimum equipment needed for a typical GMAW setup includes a MIG welding machine, a power source, a shielding gas cylinder, a consumable MIG wire, a welding gun, and a ground clamp, also known as the work clamp.
Wear basic safety equipment such as a welding helmet to protect the eyes and face and welding gloves to protect hands from hot weld spatter.
While the shielding gas protects the weld pool from atmospheric contamination, it’s imperative to understand how different shielding gasses affect the resulting weld.
There are two classifications for shielding gasses:
Technically, MIG welding requires the use of inert gas only. That’s why people call the process “metal inert gas” welding.
If the shielding gas mixture contains active gasses, the name switches to “metal active gas” welding, or MAG for short. But most people call both approaches MIG welding because there isn’t a distinctive difference.
Read more: MIG vs. MAG Welding
Active gasses influence the weld pool, spatter amount, and penetration depth. Inert gasses don’t interact with the welded metal.
However, inert gasses also modify the welding characteristics to an extent. For example, helium is inert but improves heat input, penetration, and travel speed.
Usually, MIG welding carbon steel requires a mix of 75% argon and 25% CO2. It’s also possible to MIG weld mild steel with 100% CO2 to achieve better penetration. But welding aluminum requires 100% argon or an Ar/He mixture.
You can learn more about MIG welding shielding gasses here.
Various industries use MIG welding, from vehicle manufacturing to construction and general fabrication.
It’s easy to master and provides one of the highest production rates of all manual arc welding methods. Therefore, professionals and hobbyists use MIG welding often.
MIG welding is the most common metal joining method in industrial applications since it’s easy to automate and has a high degree of flexibility. Most manufacturing plants use the MIG process to perform more than 50% of their welded joints.
The most common MIG welding applications include:
Read more: What is MIG Welding Used For?
What matters most for weekend warriors and individual professionals is how portable and affordable manual MIG welding equipment has become.
MIG welders are easy to set up and often work with a 110V input, making this welding process accessible to anyone just about anywhere.
The ease of use and flexibility make GMAW the go-to choice for most welding applications.
Related: 4 Most Common Welding Processes (MIG, TIG, STICK FCAW)
Related read: MIG Welding vs TIG welding
To MIG weld, obtain the following equipment:
Certified MIG welders can find work in almost every industry since the welding method is widely adopted. Plus, MIG welding is easy to learn, and it only takes a few weeks of training to pass the welding certification tests. So, this is an excellent career for people who love hands-on work.
Almost every manufacturing facility needs certified MIG welders. If bending, shaping, cutting, and MIG welding raw materials sound interesting, a welder fabricator job may sound right. The U.S. national median pay is $44,000, and the most dedicated fabrication welders earn above $75,000 yearly.
Construction ironworkers also need to know how to weld. While this job often relies on stick welding (SMAW), they prefer MIG welding when the welding area guards against wind drafts, and they need high deposition rates.
Creating a welding shop is a great way to build a career based on MIG welding. Shops can repair cars, farm equipment, tools, boilers, and more. Welding shops also contract to fabricate construction parts, or welders can work as a subcontractor for a larger manufacturing facility.
Whatever industry seems most interesting, the chances are high that it has a strong demand for certified MIG welders.
Learning to weld in a recognized welding school like the Tulsa Welding School or Lincoln Electric Welding School will help tremendously. These educational institutions will teach their students well and help them land excellent jobs after graduation.
MIG welding is a widely adopted metal joining method. It’s the least challenging arc welding process to master and provides high welding speeds. As a result, the MIG welding process offers one of the most efficient and productive choices for many applications.
Because the welder feeds the electrode wire automatically, MIG welding equipment is simple to set up and use. Plus, MIG welding machines are more affordable than TIG welders. But GMAW offers fewer features for arc control.
Almost every industry depends on MIG welding. While there are innovative variations of MIG welding, like Fronius’s cold metal transfer (“CMT”), traditional MIG welding will remain the top metal joining method for the foreseeable future.
Want more information on Flux Cored Welding Wire? Feel free to contact us.