MIG welding is a popular method of joining metals together. It uses an electric arc and a shielding gas to join several pieces of metal into a beautiful finished product. But sometimes, welders can forgo the use of gas tanks and rely solely on the wire consumable. This is why it's also referred to as flux-core MIG welding.
Before you purchase a MIG welder flux, know that these are the benefits that come with it.
Welding with a flux-cored wire brings less distortion to the metal being welded. That's because the flux shields the welding zone from elements surrounding the atmosphere that may cause porosity in the welding finish. In addition, a slag is also formed as a type of protective layer on the weld, giving it even more protection as the welded part cools down.
The flux shield combined with the slag formation prevents any disruption or undue deoxidation that may affect the quality of the weld. So when the time comes to remove the slag, you get a nice, clean-looking weld.
Just like MIG welding, using flux-core on a MIG welder doesn't require as much experience to properly use. It's even more straightforward to learn and use than reloading a solid wire and doing the typical MIG process.
When doing MIG welding with a flux core wire, you don't have to purchase and set up gas shields. Instead, just reload the flux core wire spool and input the metal thickness on the welding machine, and you're ready to fire that welding gun.
The good thing about a flux-cored welding setup is it can still weld even if the metal is unclean. With MIG welding, you have to make sure that your workpiece is in good and neat condition before you start working. But if you have a flux-cored wire and you're working on a project that involves rusty or dirty metal components, you can easily switch it up with your solid wire, ditch the gas mix, and start.
Using flux-cored wire on your MIG machine doesn't reduce its flexibility. On the contrary, it may even enhance it. Flux-cored wire welding can be used in all welding positions—vertical, horizontal, flat, and overhead.
Switching up to flux-core also affects your overall mobility positively. Your MIG machine isn't tied up to any gas tank. And if your welder is portable and its power cord is lengthy, you can carry it around the workshop with ease, unencumbered by any concerns about tugging on the gas tubes.
Spatter is the welder's fireworks, making the whole activity look really cool. But if you're someone who knows any better, those sparks flying off the welding zone causes inefficiencies. You'll be cleaning up your workspace more. It can also burn through your safety outfit, affecting the welding cosmetics enough to give you extra work.
Flux-core wire does not need to use shielding gas—decreasing spatter. This equates to less waste compared to some other welding methods. You'll also need less protection against spatter.
If you've ever used an oxy-acetylene torch, you know that it takes a chunk of your peace of mind when you're using it. The gases used in this welding process are highly flammable, and the tank is combustible. It’s dangerous enough to be regulated for occupational safety. And if Murphy's law gets its way, not following the rules and regulations will eventually lead to problems.
The oxy-acetylene torch has a wide range of uses, but if you're aiming just to do welding, the safest way to go is by using flux-cored wire. The shielding gas is already on the electrode consumable, so there's no need for that edge-of-your-seat flammable gas setup.
While the flux-core wire is a great alternative to reduce the spatter, there's a tradeoff: more fumes.
When it burns along with the electrode wire consumable, the flux material's shielding produces more fumes that are toxic and can be a cause of occupational and health hazards for the welder. That's why flux-core welding is recommended for outdoor use, or if used indoors, the workspace must have enough ventilation and supply of circulating air. The welder must also ensure they're wearing welding helmets with built-in respirators to double-down on safety.
Compared to solid wires of MIG welding, a flux-cored wire spool is more expensive because of its added self-shielding feature. But, on the other hand, while a flux core welder for MIG may cost you more in terms of the cost of consumables, it may actually save you money.
A flux-core wire will save you time and other resources if you look at the big picture. You don't have to spend time and effort setting up shielding gas when you already have it integrated into the electrode consumable. In addition, of course, this consumption removes your gas cost.
Flux-core wires can be more prone to burnback and birdnesting. Burnback occurs when the wire melts significantly and forms a round shape on the tip—this is caused by the machine not feeding the wire at the required speed or holding the welding gun too close to the workpiece.
Flux-core can also be prone to tangling on the wire feeder, a problem known as birdnesting. When this situation occurs, the wire feeding on the welding gun's torch will stop. This will cause a disruption in the welding activity and may significantly affect the quality of the weld because of undue discontinuation.
Flux-core wires are great for use in small projects. Unfortunately, the welding finish doesn't look very appealing.
Unlike with Tungsten Inert Gas (TIG) welding, the flux doesn't provide that good of an appearance because the electrode filler and the flux shielding is preset: you don't get to choose how much or how often you get to dip a filler rod metal. You also don't get to manipulate the shielding gas mixture which can affect the weld quality.
Welding with a flux-core can sometimes produce work defects. Undercuts, where the workpiece is dug by the weld but not filled in, can be tough to repair using a flux core wire. There may also be slag inclusions that stick to the weld, which can be hard to clean. And if the settings aren't correct, your welding finishes may have small holes in them. A rework must be done in most cases because repairing the finished pass is very difficult.
MIG Welding stainless steel with flux-cored wire will be difficult if it's more than 20 gauge. Flux welding metal thickness of this level won't have a good outcome. Flux-cored welding using a MIG machine is recommended for thicker metals that are below 20 gauge, so if you're working on thinner metals, best switch to solid wire instead.
Just like any welding process, flux-cored wire welding has its pros and cons. What matters is that you have insight into when to use flux-cored wire to replace your solid wire on a MIG welding machine. This will allow you to use the welding process effectively to yield the best results.
If you want to know more about flux-cored welding and other related knowledge, go over to Welding Buddy and get tips, insights, and recommendations that you need to be a better welder.