Flux Core Welder: What Are They Good For?

Cheap, portable, and easy to use, the flux core welder is a hotly debated topic in the welding and metalworking space. When beginners are looking for their first welding machine, opinions often clash between those that believe a stick welder is the best way to start, and those that believe a MIG or flux core welder is the way to go.

The truth is, there is no best way to start for everyone. While a stick welder may be the traditional way people use to begin their welding journey, for most home use it isn’t the most efficient solution. The MIG welding process is faster, and often times less frustrating for the occasional welder or hobbyist.

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What is a Flux Core Welder?

First, lets get something straight. Most people call flux core wire welding “flux MIG”. Flux core welding, by definition, is not MIG welding.

MIG stands for Metal Inert Gas. In true MIG welding, a shielding gas is used to prevent contamination of the weld while a solid metal wire is melted to join pieces together. The wire comes on a spool and is fed through the welding lead to the gun by a motor inside the welder. Inside the lead there is also a hose for the shielding gas to travel in.

A flux core welder shares some similarities in design to a MIG welder, however it does not use gas to shield the weld. Flux core wire has an inner flux core surrounded by metal. As the metal melts, the flux inside burns to create its own shield, without additional shielding gas. Flux core wire comes on a spool and is fed through the lead by a motor in the welder like a MIG welding machine.

It is worth noting that flux core wire can be ran through a standard MIG welder, however you can’t run standard MIG welding wire through a flux core welder. Be sure to keep this in mind when purchasing a welder. If you plan on MIG welding in the future, it can be cheaper in the long run to buy a MIG welder from the start and use flux core wire in it. When you are ready to MIG weld, all you will have to do is purchase MIG wire, a tank of shielding gas, and regulator.

Flux Core Welder

What are the Benefits of a Flux Core Welder?

The first benefit of a flux core welder is cost. Flux core welders are less complex than true MIG welders because they don’t have any of the components required for shielding gas. A decent flux core welder can be had for under $200 USD, and it can stick weld too! The only consumables that need to be purchased are the flux core wire, and some spare tips for the welding gun. There is large investment in gas cylinders required, nor is there gas to run out of half way through a project.

Flux core welders are extremely portable. The inverter welders available today are more efficient resulting in lighter weight and a smaller size. With most flux core welders weighing under 20 lbs, they are easy to move around and bring to your work. Since shielding gas isn’t required, there are no gas bottles, hoses, and regulators to worry about moving. You can even throw the welder in the back seat and take it to your buddy’s house if you need to.

Adding to their versatility and portability, most flux core machines are 110v and there are no special requirements for power. Standard outlets will work, just make sure the circuit you are plugging into can supply the amperage required by the welder. Often times a 50 amp breaker is recommended if you intend to operate the welder close to its maximum output.

MIG welding outdoors with shielding gas can be troublesome. Often times you need to create a wind block and turn the gas flow up to keep the shielding gas from being blown away. Since a flux core welder produces its own shielding, welding outdoors is no problem. There is simply no shielding gas to be blown away.

When it comes to ease of operation, it is hard to beat a flux core machine. Set your amperage and wire feed speed and you are off to the races.

What are the Disadvantages of a Flux Core Welder?

Flux core welding has a few drawbacks. Some of them are related to the process itself, and others are related to the way flux core welders are marketed and made.

The Process

Generally, flux core welding is much dirtier than traditional MIG welding.

When the flux core of the wire melts, it creates a lot of smoke. It is important to flux weld in a well ventilated area, and ideally wear a respirator. Respirators designed to wear under a welding hood are available, and are a good idea no matter what type of welding you are doing.

Flux core wire produces slag on top of the weld that needs to be cleaned off after the weld is completed. The slag that forms on top of the weld is what protects it from contamination by air. Once the weld has sufficiently cooled, it can be removed without any concern. It is important to note that if the weld requires multiple passes, the slag must be removed before the next pass.

The flux in the wire also causes a lot of spatter. The spatter can build up on the tip of the welding gun, as well as stick to other pieces in the immediate area. There are sprays available to make spatter less likely to stick, and make it easier to remove. Otherwise, it will need to be ground off with a flap disk or grinding wheel.

The Machines

Some disadvantages aren’t related to the process, but in how the machines themselves are made. Typically, manufacturers market flux core welders to beginner and home welders. Therefore, they are made to be inexpensive.

You will find that most flux core welders only operate on 110v power and only have 100-150 amp output. This limits the welding capability to relatively thin metals. Realistically, 1/4″ material is the thickest metal you will be able to weld with a flux only welder.

Many machines are sold with pretty short ground clamps and leads. While this isn’t a deal breaker, sometimes you will need to move your welder closer to the work.

Additionally, the overall build quality of these machines tends to suffer in order to cut costs. There are some good options out there, however.

Flux Core Wire

Should you Buy a Flux Core Welder?

Should you buy a flux core welder? That answer really depends on what you want or need a welder for in the first place, and your future goals.

If you want a simple reliable welder for repairs around the house or farm that you can easily transport, then I would say buying a flux core welder is a good idea. If you need to weld outdoors a lot, there won’t be any shielding gas to worry about and flux core machines are lightweight and compact.

If you need super clean welds or don’t want the hassle of the extra clean up that comes with using a flux core wire, a flux core welder may not be a good fit for you. You may want to look for a true MIG welder with a gas bottle, or a TIG welder, depending on what materials you plan on working with.

Remember, you can run flux core wire in a standard MIG welder without shielding gas. If you are taking up welding as a hobby to learn and keep expanding on, spending the extra money on a MIG welder and running flux core wire while you learn is a great option. Once you are ready, you can purchase or rent a gas bottle and MIG weld with the same machine.


YesWelder offers a 135 amp machine that comes with a welding gun and and an electrode holder for stick welding.

I personally have their TIG205-DS TIG welder and have been impressed by its value. They have a wide range of other machines and welding gear as well.

If you are looking for a name brand, it is hard to go wrong with the Forney Easy Weld 140 FC-i.

It has an all metal case, and is designed to hold both 2 and 10 pound spools of flux wire. This comes in really handy if you plan on using it a lot.

Another great flux core welder, and the one I own, is the Titanium 125 from Harbor Freight. Harbor Freight has really brought the quality of their welding machines up over the last several years. The wire that comes with the machine is pretty poor quality, however I have had great luck with the Vulcan wire that Harbor Freight sells.

Final Thoughts

Flux core welders definitely have a place. While being lightweight and portable, they offer the mechanics of MIG welding without shielding gas. Being easy to use and inexpensive, a flux core welder is the perfect machine for a homeowner that wants to do basic repairs, or someone testing the welding waters.

They can handle a lot of tasks, although clean up may be required depending on the projects final use. If you need to weld stainless, Blue Demon even offers Stainless Flux Core Wire.

I have used my flux core welder to build garden trellises, gates, and even a 20 ton hydraulic press. They are great for scrap metal art as well! Find some scrap metal to build a few projects and get started.

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