I’m Garrett Strong with makemoneywelding.com.

I’ve been helping beginners & hobbyists learn to weld online for several years now.

You may also enjoy these articles… The Advantages Of No Gas MIG Welders and 8 Ways to Avoid Weld Porosity”.

I’ve helped thousands of people just like you get started learning to mig weld with my beginners guide to MIG welding.

Every welding process has a way of shielding the molten weld puddle from the atmosphere. Why is it necessary to shield the weld puddle?

In This MIG Welding Training You’ll Discover Why We Use Shielding Gas And Flux

Because if you don’t have a way to protect the weld puddle from coming in contact with the atmospheric gases like oxygen and nitrogen, then your weld will get contaminated.

What does that look like?

A weld that hasn’t been shielded using either a shielding gas or a flux will develop little pin holes in the weld known as porosity.welding porosity

Is porosity the end of the world? No, but it will weaken your welds dramatically.

Let’s take a look at flux first, and then we’ll look at the shielding gas that is used when MIG welding and TIG welding.

In this image are some welding rods for a stick welder. These rods are made up of a certain kind of metal, and they have a flux coating on the outside.

welding-electrodesWhat happens when you strike an arc with one of the stick welding rods is that the metal rod will begin to melt, creating the weld bead. Also, the flux begins to melt creating a slag coating on top of the weld.

This slag coating is what helps the weld from developing porosity.

That was flux for stick welding. Now let’s talk about flux for wire feed welding.

When you buy a mig welder you will have 2 options.

  1. Option #1: Use Shielding Gas
  2. Option #2: Use Flux Core Wire

Flux core wire is simply the opposite of a stick welding rod. Rather than the flux being on the outside, with flux core wire it’s on the inside.

The process is the same as stick welding.flux core wire close up

When you weld using flux core wire, the wire melts and becomes the weld bead. The flux on the inside of the wire then creates a slag coating just like with stick welding rods.

Let’s Talk Shielding Gas For MIG Welding

Shielding gas is great because it allows you to protect the weld puddle from the atmospheric gases, while keeping the weld clean. There is no slag!

When you hook up a gas cylinder to your MIG welder, set the flow meter, and press the trigger on the MIG gun several things will occur.

You will release the gas out of the MIG nozzle which covers the weld, the wire will start feeding, and the arc will start.

The gas typically used when MIG welding is a mix of carbon dioxide and argon. Also called C25 gas because it’s 25% Carbon Dioxide and 75% Argon.

The first thing you will notice when MIG welding with gas is that the welds are very clean.

This is nice when you’re working on projects that you don’t want to beat on with a chipping hammer.

If you want to learn how to MIG weld like a pro, download my free report MIG Welding Mastery while it’s available.


Garrett Strong

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