MIG Vs Flux Core Welding: What Are the Differences?

Each one of us has a different view when it comes to welding devices. Some might prefer Stick, while some might prefer TIG. On the other hand, there is an ongoing debate about MIG vs flux core where people are taking sides, just like TIG and Stick’s topic.

Nevertheless, we are not the people who take sides. Our experience on both of the methods is plenty. We have spent countless amounts of time using both. And we are here to offer you our unbiased thought about both of them.

Now, what we expect from you is to absorb all of the information regarding the topic and choose the winner by yourself because there is no clear winner in our eyes. Are you wondering why there is none in our views? Well, for that you must carry on reading.


Flux Core Welding vs MIG In Detail

As we have mentioned, there is no clear winner when a comparison of two of the welding processes is taken into hand. The reason behind that would be that there are cases where one will shine the most, while the other would be a bit average. To give a clear glimpse of what we are talking about, here is a description of each:


Flux Core Welding

MIG vs flux core

Allow us to first talk about one of the earliest processes that emerged in the welding community. The flux core welding is also known as FCAW (Flux-Cored Arc Welding) by many. That is basically the short form of the process.

You might have seen the denotation is on tattoos and on the leather jackets that most of the welders like to wear.

On that note, you might have also heard about the shielding with an arc. This is just an alternative to that exact process. The gas that is fed for the arc shielding process is a solid gas. This gas is also referred to as a shielding gas by many. However, no matter what the gas is called, the process is the same.

In reality, the process can be categorized into two types. One would be the shelf-shielding process, while the other is gas shielding. The primary difference that lies between the two is that in the gas shielding, you will require a continuous gas flow.

On the other hand, the shelf-shielding will not require any sort of external shielding gas. That is why you would have the capability of carrying different tasks using them without having to go through the hassle of carrying a gas can with you.


Advantages of Flux Core Welding

Because of having a plethora of unique properties, the FCAW achieves some of the advantages that are not commonly seen on the other welding processes. That being said, let us give you an idea about the benefits that you can expect to enjoy by choosing this welding process:

  • Portability

As these machines have a built-in shielding method, you will not find it necessary to carry around an extra tank with you. For that reason, you would be capable of carrying this almost anywhere without facing any sort of issues.

  • Speed

In comparison, the FCAW is quicker than some of the other welding processes that are available. By keeping that factor in mind, we think it will be safe to state that you should be capable of finishing most of the welding tasks in a short amount of time.

  • Capability

Because of the power that it packs, it will offer you the ability to carry out welding tasks in most of the workpieces. Even if the workpiece is relatively thick, the chances of you finding it incapable of welding will be pretty low, thanks to the power that it packs.

  • Versatility

Most of the FCAW machines you will find in the market can be operated in both automatic and semi-automatic modes. That means depending on the task that you have in hand, you can tune it accordingly and get an adequate amount of result on your workpiece.


Drawbacks of Flux Core Welding

Just like any metal fabrication tool that you will find in the market, these machines are not perfect by any means. There are some things that you might want to keep in your mind before picking one of these up. They are:

  • Capability

Remember how much we praised the power of these machines. Well, it is a good thing and a bad thing at the same time. For having such an amount of power, these are only ideal for the thicker metals. You will not get proper results if the workpieces are relatively thin.

  • Not Suitable for Newbies

If you are totally inexperienced, we would recommend you to pick something else because the gun positions of this one can be a bit critical. However, you can get the hang of it if you practice welding tasks enough with it.


MIG Welding

MIG Welding

One of the semi-automatic welding processes that have been catching a lot of attention nowadays is the MIG machines. For this, you are going to need a wire connected to it, which will draw power directly from the source. And the wire also works as an electrode. It has the function of connecting the two metals.

During the operation, both the wire electrodes and the inert gas will flow through the gun. The inert gas is there to provide a shield from contaminants. That means it will not be necessary for you to worry about the airborne debris ruining the workpiece. For this characteristic, you can work with non-ferrous metals at ease.

Unlike the flux core welding process, this one does not have any variation. All of the devices that are available in the market will adopt the same operational procedure. The only thing that will change would be the power and the capability of the machine.


Advantages of MIG Welding Machines

The welding process did not achieve all of the popularity for being nothing, did it? Well, it has a lot of things going. And the main benefits that you can expect getting by considering this one are as follows:

  • Clean

Unlike some of the other welding processes, this one is known for offering a significantly less amount of spatter. And it achieves that by utilizing a soft arc operational procedure. As a result, the amount of cleanup that the workpieces are going to require will be pretty low.

  • Operational Procedure

Another thing that made this one quite popular is the easy operational process. There are not that many hassles in operating one of these. That is why this one is the one that is recommended to the newbies the most. Even the setup and maintenance process is easy.

  • Controls

Even though the operational process might focus on the newbies, it offers a good amount of controls for the intermediates. You will be capable of fine-tuning the machine to the way you want to by having a bit of knowledge about the device.

  • Capability

Aside from all of the factors, one thing that most welders find amazing about these machines is the capability to work with different types of metals. For having a unique operational procedure, it can work with aluminum and other non-ferrous metals.


Drawbacks of MIG Welding Machines

As you might have guessed, this device is not perfect either. It has some shortcomings, which we think you should factor in before making a purchase decision. That being said, the main limitations that you will find when using one of these are:

  • Additional Tools

Usually, a MIG machine will not ship with all of the things that you will require. There are some things that need to be purchased alongside that kit. For that reason, you would need to spend extra money to get a complete set of MIG welder.

  • Not Ideal for Thicker Metals

Another thing that you need to stay wary about is the capacity. This tool is not the one that you would want to pick if the workpieces you handle are generally thick. The results that you will get when handling projects such as that might not be satisfactory.


Which Factors Makes MIG Better Than Flux Core?

After having proper knowledge about both of the welding machines, you probably want to know about the parts where the MIG is better than the flux core. Well, that is exactly what you are going to know about in this section.


Quality of the Weld

First and foremost, the quality of the weld that the MIG is capable of offering is pretty high in comparison. There is a minimum amount of slag, which results in a minimum amount of spatter produced. That means the workpiece will be clean, and there will be less amount of cleaning required.


Ease of Use

As we have mentioned earlier, the operational procedure of the MIG is comparatively easier than the flux welding machines. For that reason, the chances of you facing difficulties when you are working on projects with this will be considerably low.


Which Factors Make the Flux Core Better Than MIG?

Like MIG, the flux core is also better in some of the factors. And those factors are exactly why many of the buyers opt for the flux welding method instead of the MIG. That being said, the factors that make the flux core better than MIG are:



The flux core machines pack a substantial amount of power. With the amount of power that it packs, you would be capable of finishing most of the welding tasks in hand quickly. So, working on a large-scale project will seem like a hassle-free process for you.



In the tasks where you are handling workpieces that are a bit thick in comparison, the flux core welding should be your go-to choice. These are capable of working with thicker metals, which makes this ideal for industrial works.


Does MIG Offer Better Metal Penetration Than the Flux Core?

MIG Welding for Metal

Some might argue that the flux core is better when it comes to metal penetration. But is that statement actually true? Well, for that, you need to understand the factors that dictate the penetration capability.

The two primary factors that will dictate the penetration capability are the amperage and the voltage. As with the other parameters, the higher these factors are, the better the penetration capability will be.

For example, the machine that can work with a higher level of amperage at a higher voltage can penetrate thicker metals easily. On the other hand, the other factor is the thickness of the metal. If the workpieces are reasonably thick, the chances are that you will find the machines cannot penetrate through those properly.

Let us give you an example to perfectly illustrate the thing that we are trying to state here. For instance, you are working on a project that is 4.8 mm thick. You will find that you are getting a great outcome with the 0.030 flux core wire.

However, if you take the same diameter wire with a MIG, you will notice that the penetration is not lower or higher than 3.175 mm. Do note that, the penetration example that we are giving here uses a power source with a 140 voltage rating.

One thing that is certain for the flux core is that you are going to get a better result with the thicker metals. Considering that, we think it would be safe for us to state that flux core has a better metal penetration capability without considering the other factors.

On the other hand, if the metal workpieces are not that thick and you want cleaner results, you should choose the MIG over the flux core.


Final Words

On the ongoing topic of MIG vs flux core, our conclusion would be to pick the one by considering your skill level and the work requirements. By doing so, you would stay at a pretty place, no matter which side you choose in between the flux core welding vs MIG.