Flux-core is the Hunchback of welding processes. Like Quasimodo of Notre Dame, flux-cored welding is sometimes cast away because of its hideous appearance. But with a little bit of love and a grinder, it cleans-up real nice (flux-core that is—don’t use a grinder on Quasimodo).

In fact, flux-core (also called FCAW) has some serious advantages that can actually make it the best process in certain situations, especially for beginners looking to get into welding as a hobby. In this article, we’ll cover why you should care about flux-core and how to get started.


Why “Gasless?”

Flux-core is sometimes called “gasless MIG welding,” as it does not require separate shielding gas tanks. However, the term gasless is about as accurate as the Bear’s quarterbacks. With normal MIG welding (or GMAW), a shielding gas is needed to protect your weld from oxygen, as it will cause the metal to corrode. 

FCAW does not require gas cylinders like this, but MIG (GMAW) does.

While flux-core doesn’t require external gas cylinders with shielding gas, it is not actually “gasless.” Instead, the wire it uses already contains a shielding gas, which is released as you weld.

This makes flux-core a great option for someone looking to get started in welding. Welding already requires a lot of equipment. Flux-core makes it possible to begin welding without having to purchase and fill tanks of shielding gas, reducing some of the barrier of entry.

While stick welding also uses electrodes that already include shielding gas, stick welding can be quite tricky to do well. Flux-core takes the accessibility of MIG welding and makes its upfront costs cheaper. It also actually performs better in outside conditions, especially in windy weather.

It’s important to know that flux-core has lower starting cost, but the price of flux-cored wire is more than MIG wire. If you know you’re going to be doing a lot of welding and don’t mind the initial investment, GMAW (MIG welding) might be the better option. That being said, many MIG machines will also do flux-core. You can always start with flux-cored wire and graduate to your own external gas tanks. If this is your plan, just make sure you double check that the machine you’re interested in can do both processes before you purchase. For instance, the Millermatic 211 is one of our favorite MIG welders of all time and can do both FCAW and GMAW.


The Basics of Flux-Core

First and foremost, you’ll need to make sure you have a welding machine capable of flux-cored welding. Here’s a complete list of all the top FCAW machines offered from the best store on the web. You’ll also need flux-cored wire, which you can purchase at the best price online here.

Setting up your machine depends a lot on the specific equipment you’re using. Consult your user manual and reference grid to get the right settings for the material and thickness you’ll be welding. 

One of the most important things to remember is that flux-core requires DC electrode-negative polarity, the opposite of MIG welding. Depending on your machine, you might need to switch your leads around. If you find you’re unable to produce a good weld, polarity should be the first area of troubleshooting. There is nothing more frustrating than spending hours trying to weld, only to realize you needed to make a 30-second adjustment.

Also pay special attention to your drive roll tension and wire speed. Most experienced flux-core welders set their tension so they can easily halt the wire with a finger.


Ugly Welds

Even when done right, flux-cored welds look awful at first. You’ll notice a significant amount of spatter, smoke and sparks compared to MIG and TIG welding. Once you finish your weld, clean up is required. Use a grinder and wire brush to remove the slag, spatter and smoke residue. Your beads should look significantly better once you’re done.

Because FCAW just looks ugly, it can be hard for beginners to know if they’re doing it right or doing something wrong until after they’ve cleaned it up. Ultimately, the best solution here is to practice. Make sure you use a scrap piece of metal and try laying a few beads. The trick is to know what angle, distance and speed you need without as much visual feedback as you’d get from MIG or TIG. Once you’re able to trust the process, you can create welds that are as strong and as good-looking as MIG.


Don’t forget, Welding Supplies from IOC has the best prices on the brands you can trust. If you’re interested in flux-cored welding, make sure to check with IOC before you buy.