Welder welding big iron plate

Flux Core Welding 101: A Beginner's Guide

If you’ve never tried welding before, you might be a bit overwhelmed by all the different kinds of it. From gas metal arc welding to stick welding to TIG welding to MIG welding, it seems like no matter how much you research, there’s another process just around the corner.

Flux core welding is a type of welding that is very user-friendly and, thus, a perfect welding option for beginners. Not only is a flux core welder easy to learn, but it still results in a quality weld that most professionals wouldn’t be able to tell you did without having much experience.

In this guide, we will break down the basics of flux core welding, from what it is to how it works to what you’ll need to get started. Let’s get into it!

What Is Flux Core Welding?

Flux core welding refers to utilizing a continuously-fed wire electrode that is filled with flux – flux, when burned during the welding process, creates an atmosphere around the welding process that protects the weld from the effects of oxidation.

It does this by releasing an external shielding gas into the air that huddles around the flux core arc and surfaces being welded.

These gasses might be argon, carbon dioxide, or some other inert gas – the important thing is that they prevent oxygen and other harmful gasses from attaching themselves to the surface of the metal being welded and interfering with the integrity of the weld.

Because flux core welding uses a wire feed that continuously funnels the wire electrode into the weld, it is considered a semi-automatic process. Flux cored welding can also use two different kinds of wire electrodes. These are self-shielded and gas-shielded.

We just described self-shielded electrodes – once welded and burned, they release protective gasses that shield them from oxidation. However, electrodes with shielding gas rely on a tube to constantly funnel protective gasses into the weld to achieve the same effect.

Depending on the type of weld metal and base metal you’re working with, you’ll want to consult manufacturer instructions to determine what kind of electrode you should use.

Welder in protective equipment bent over welding surface

Advantages and Disadvantages of Flux Core Welding

The main advantage of flux core welding is that it is easy and versatile. It can be performed both inside and outside, thanks to the two types of electrodes you can utilize. Self-shielded electrodes were a godsend to welders in the 1950s, who could previously only use a welder as a whole on days when it wasn’t particularly windy – and if it was raining or misty or anything of the sort, forget it.

With the advent of self-shielded electrodes, welders could now work outside on bridges or ships without worrying about various kinds of weather.

Flux core welding is great for beginners who don’t have any welding experience. You can learn how to weld using this method easily, and the resulting weld is always good. While you might not want to use flux core welding for delicate or precise work, it’s a great option for any relatively simple welding job.

Now, when it comes to the disadvantages of flux core welding, we should mention a few things. While nearly all types of welding require that you clean and prep the weld metal, this is a little more important with flux core welding. This is because flux core electrodes can have a more challenging time bonding with surfaces with even the barest bit of dirt or grime on them.

Flex core welding wire electrodes are usually thinner and a bit more finicky than other electrodes, so if you improperly clean your weld and base metal surfaces before welding, you’ll likely end up with a bad weld. If your metal surfaces contain any mill scale, you must remove this before getting started.

Mill scale refers to the often flaky coating on metals produced through a hot rolling process. It is often seen on different kinds of iron and steel. Flux core welding also requires a post-weld cleaning session for you to take care of, so be aware before considering the job finished.

This is because wire electrodes will result in the presence of slag – this excess metal will need to be chipped off or scrubbed away for the weld to be considered strong and durable. The presence of slag not only makes a weld look chunky and rough but will also damage the overall strength of the weld if it isn’t taken care of.

Close up of welding process

Preparing for Flux Core Welding

Before you start flux core welding, you’ll need to gather the proper welding equipment. These include proper safety equipment, including a welding helmet, work gloves, and long sleeves to cover your limbs. You’ll also need the right welding gun, a proper power source, a transformer, whatever metals you’re joining together, and the appropriate electrode.

If you’re not sure whether you’re working with the right kinds of materials, then we would encourage you to check out the manufacturer instructions that come with different materials.

What we mean by that is a few things – first off, check the AWS classifications of your electrodes – this will let you know the tensile strength, conductivity, and all the other info you could need to know about your electrode. This information is vital to know whether you’re using the right stuff for various metals.

What Else Is There to Know about Flux Core Welding?

For the most part, we’ve covered all the basics and some welding tips covering what you could need to know about flux core welding. You now know what differentiates it from other kinds of welding, its basic components, and what you’ll need to get started with the flux core welding process yourself.

If you still have questions, don’t worry – at least you know what kinds of questions you should be asking. We encourage you to get into the world and start learning the welding machine yourself – it’s the best way to learn what information you’re looking for. Good luck with your flux core welding adventures!

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