How to use a MIG welder without gas

mig welder no gas used

If you have ever taken up welding as a hobby, you would know the level of creativity you can put into your projects. Welding helps to combine metals together using a very high temperature. It is used to create the outer framework for extensive machinery. At one point, we have all been a fan of Iron Man, but have you ever thought how suit like that can actually be created? The answer is welding.

There are different types of welding for different purposes. One of them is flux-cored welding. There are many advantages to using flux-cored welding. This is a gasless welding method. Instead of using gas to protect your weld, you can use a flux which protects the weld in a similar manner.

How does welding without gas work?

In flux-cored welding, a hollow wire is used which has flux inside. This provides a similar function as a shielding gas. It uses a direct current to melt the wire. The flux inside this hollow wire starts burning flux inside which is then used to shield the molten metal. The flux covers the weld with a gas that protects it from oxygen. Although this will produce a slag on top of the weld which will have to be removed afterward. However, if you used flux-cored welding which is designed specifically for this purpose, you will not need shielding gas.

In this article, we will see how to use a MIG welder to weld without gas. If you decide to use a regular MIG welder, you will have to replace the wire feed rollers inside the machine with a special type of rollers having groves in them. It’s necessary because the hollow flux-cored wire is a lot softer than regular MIG wire, with that comes the problem of damaging the flux-cored wire, it also affects the feeding speed. Also, you need to change the polarity of the welder from DCEP to DCEN, meaning from electrode positive to electrode negative.

But can a MIG welder weld without the use of shielding gas with regular wire?

The simple answer to this question is no. It does not matter what type of metal you are welding, you will always need either a shielding gas or a flux core in order to protect your weld from oxygen. Without proper shielding, you will create a lot of porosity thus you will have a very weak weld!

As you now know, it all starts with a suitable wire, and this is the one I am using:
I advise everyone to use it, it is really good, even better than the ones made by huge welding equipment manufacturers.

Advantages of flux-cored welding

  1. There is no need to carry a gas cylinder
    One of the major advantages you will find with flux core welding is that you will not have to carry around a shielding gas cylinder. Even though there are smaller ones available but the tanks weigh too much to be carried around. Not having to buy a gas tank will save a lot of cash as well.

  2. Flux core welding works better outdoors
    This type of welding works better for outdoors when compared with gas welding. Even if it is windy outside, the flux core welding will still protect the weld since the flux burns when the wire melts. If you use a shielding gas, it will disperse out with the wind.

  3. It will be able to handle welding even if the surface is dirty
    While normal MIG welding requires the surface to be completely free of contaminants, this is not the case with flux-cored welding. It will work perfectly fine even if the surface is a bit dirty or rusty.

Disadvantages of using a no gas welders      

This type of welding is very sensitive to the thickness of the metal since it uses DCEN polarity and because of that, the arc penetrated metal deeper, and because that you might start blowing holes in your project. Furthermore, you might not be able to remove the flux from very thin sheet metal without damaging it. Apart from this, another drawback is that you will not be able to see the formation of the seam while working with flux-cored welding.

When should you use a flux core welding?

There can be multiple scenarios in which you can use flux core welding instead of gas metal arc welding. One of these is when you have to work outside. This is because while you are working outside, the weather conditions are out of your control. If the condition outside is windy, the flux core will be a better option.

Another case is when you are working on dirty surfaces. Using a shielding gas for welding on the dirty surface will not create a strong enough bond between the wire and the metal. However, flux-cored welding can bond better on dirty surfaces. It is good for welding dirty old gate or even rusty surfaces with it.

Using MIG welder without gas

If you are a beginner, MIG welder without gas is one of the best options out there for you. This is one of the classic arc welding types out there and is even easier to handle than MIG welding. As there is no such thing as gasless welding because a weld always requires protection from oxygen, a MIG welder without gas has its own protection. MIG welding without gas is also known as flux core wire welding.

  1. Change the drive roll to knurled one
  2. Install the flux-cored wire
  3. Change the polarity of the machine. The welding gun must be connected to the minus whereas the metal itself should be connected to the positive connection. This is known as DCEN.
  4. Set the wire feed speed and amps and weld away.
  5. Practice, Practice, Practice!

In addition, an important thing to remember, using a welder without gas with flux core welding wire, you can not usually lay multiple passes!


Using a MIG welder without welding gas has its own set of advantages. You don’t have to buy a welder that only gives you the option of flux core welding, you can do the same with a MIG welder as well. Although you will have to adjust a few things, the results will be the same.

Hope this post was helpful! If you have any questions, comment below!

Categories MIG