The Battle Of Flux Core Vs Mig Welding

Flux core welding and MIG welding are very common welding processes all over the world. Arguments continue to rise on which one is better than the other. Some people strongly maintain that MIG welding is better than Flux core welding. Others say that Flux is better than MIG.

Beginners find it even more confusing. According to practical reviews from different welders, these two welding processes produce similar results. Both FCAW and MIG welding has advantages and disadvantages. The battle on Flux Core Vs MIG Welding is yet to find a winner.

Flux Core Welding

What Is Flux Core Welding?

Flux core welding is an arc welding process using a tubular wire filled with flux which is feed through the gun to the point. This welding process can be automatic or semi- automatic.

Where Is Flux Core Welding Used?

Flux core welding is used in different industries in the world. These are:-

  • Ship building
  • Under water welding
  • Welding Pipes

What Are The Advantages Of Flux Core Welding?

  • FCAW can be done outside even in windy conditions.
  • Unlike in MIG welding where welding must be done on clean metals, FCAW can be done on dirty or rusted metals.
  • FCAW is portable because you do not have to carry a gas cylinder every time you’re out to weld.
  • Flux core welding can be done on overhead position and also vertical position.

What Are The Disadvantages Of Flux Core Welding?

  • Produces a lot of unpleasant fumes.
  • The wire that is used as an electrode is costly.
  • Flux core welding produces slag that is removed after welding.
  • Unlike MIG welding, flux core welding is only done on ferrous metals.

Mig Welding

What is MIG Welding?

Metal Inert Gas welding is a process of heating a solid electrode and using an external gas to shield the molten material in the arc to two base metals together.

Where Is MIG Welding Used?

MIG welding is used in different in different welding industries. These are:-

  • MIG welding is used to weld both ferrous and non ferrous metals.
  • MIG welding is used in ship building.
  • Most automotive industries use MIG welding for repairs and fabrications.
  • MIG welding is used in production of pressure vessels.

What Are The Advantages Of MIG Welding?

  • MIG welding produces smooth welds.
  • Although slag is formed during MIG welding, it’s easier to remove the slag unlike in FCAW.
  • MIG welding can be used to weld both ferrous and non ferrous metals.
  • This welding process produces little spatter.
  • MIG welding is the easiest process to learn.

What Are The Disadvantages Of MIG Welding?

  • MIG welding cannot work on dirty or rusted metals.
  • This process cannot be done outside especially when it’s windy because the shielding gas will be blown away resulting to a weld full of porosity.
  • The Gas tank makes MIG welding less portable because you need to carry the MIG Welder and the MIG Welder Gas tank with you to the welding site.

Is Flux Core Welding The Same As MIG Welding?

The wire used in these two welding processes is what differentiates them. In MIG welding, the electrode is shielded by gas from an external tank.

Flux core welding has a tubular electrode which is filled with flux that protects the molten bead from the atmosphere. The flux found in the welding wire makes it easier for one to weld outdoors. This is totally different with MIG welding.

Flux Core VS MIG Welding

Are you torn between the two welding processes? These considerations might give you a clue on which method to use:-

1. The Electrode Used

In Flux core welding, a tubular electrode filled with flux is used. The flux inside the welding wire shields the weld pool from contaminants. In MIG welding, a solid electrode is used together with an external shielding gas which protects the weld pool.

2. Shielding Gas

In MIG an external Gas Tank is required to produce the shielding gas. The FCAW doesn’t require a gas tank. These gases used in MIG welding are:-

                – Argon

                – Carbon dioxide

                – Helium.

Sometimes flux core welding can use the external gas for a stronger shield. The same gases used in MIG are used in dual flux core welding.

3. Metal Penetration

Some people say that flux core welding has a greater metal penetration. The metal penetration is determined by the amperage of the welding machine and the thickness of the metal being welded.

In flux core welding less amperage is used for thicker metals while in MIG for you to weld thicker metals you need higher amperage.

4. Type Of Metal

The type of metal you want to weld determines the welding process you will use. You should ask yourself which metals you can be able to weld with flux core. You should also know which metals you can weld with MIG and those that you can’t.

Flux core welding can weld all ferrous metals. Examples of ferrous metals are:-

  • Copper
  • Mild Steel
  • Carbon Steel
  • Stainless steel.

MIG welding is better because it can weld both ferrous and non ferrous metals.

5. The Cost

MIG solid wires are cheaper compared to flux core wires. However there are additional things that a MIG welder needs that is not needed in Flux core welding. These are:-

  • The regulator
  • Gas Tank
  • Hose

When you put all the aspects into consideration you’ll see that MIG is expensive than Flux core welding.

6. Polarity

AC and DC can be used in both welding techniques. Professionals advise that Direct Current Positive Electrode should be used because it produces better welds.

7. Quality Of The Weld

Both MIG and Flux Core welding produce strong welds. The only difference comes in appearance. MIG welder produces a smooth weld than a flux core welder.

Can You Use A Shielding Gas And A Flux Core Wire At The Same Time?

When welding thicker metals, you can use a shielding gas in flux core welding. The shielding gas will help the molten weld to solidify quickly.

Final Word

Looking at both flux core welding and MIG welding it’s quite hard to get a winner. Both of these welding processes have their techniques that are unique in welding different metals. For you to get the best bout of these welding types, ensure that you’re using the right metals for welding.


Edward, a seasoned welding expert, shares his extensive knowledge and insights on to help you enhance your welding skills. is reader-supported. When you purchase through links on our site, we may earn an affiliate commission at no additional cost to you. See affiliate disclaimer.