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Best Flux Core Wires: Buying Guide + Reviews

Flux Core Arc Welding (FCAW) has been gaining some popularity lately, and it’s not hard to see why.

It’s a technique used to join two metals together -mostly mild steel- through welding their joints. It produces a beautiful weld bead and has a high deposition rate. Besides, it’s easy to learn and has versatile applications.

The main aspect of an FCAW is the welding wire. That’s what we’ll be talking about here.

Do you get those nasty flashbacks of your flux core wire tangled in its spool’s reel?
I used to, but I don’t anymore, and I’m here to help you stop them. Today, I’ll help you pick the best flux core wire.

Read on to discover how!

INETUB BA71TGS .030-Inch on 2-Pound Spool Carbon Steel Gasless Flux Cored Welding Wire
1,883 Reviews
INETUB BA71TGS .030-Inch on 2-Pound Spool Carbon Steel Gasless Flux Cored Welding Wire
  • Gasless flux cored welding wire AWS E71T-GS, Smooth arc action, High feedability, Easy to weld
  • Shielding gas is not required, All positions, Single and multi pass welding
  • Low spatter, Full slag coverage, Easy slag removal, Porosity free, Good bead appearance
  • Made in Italy from the finest quality materials using state of the art technology under highly respected labour conditions

Pros

Cons

Another interesting wire to look at is the self-shielded INETUB carbon steel gasless flux core wire. It feeds smoothly into the welder with low spatter and produces a beautiful smooth arc. You can see why it’s easily one of my favorites!

INETUB is also made in Italy, just like Inefil. It has a similar set of properties at a reasonable price too. You can use the 0.030 for mild metals, or you can opt for the 0.035 for thicker gauges.

There are 2 spool sizes of INETUB; the 4 inches (2 pounds) spool and a bigger 8 inches (10 pounds) one.

What I like about INETUB’s flux wire is its versatility. You can use it for single or multi-pass welds, in addition to using it in all positions, vertical and horizontal.

Regarding mechanical properties, this wire is worthy of respect. It has an above-average tensile strength of 82.7 KSI, and as I said before, it requires no shielding gas. It works with DC straight polarity electricity. Besides, it has a high deposition rate resulting in a beautiful weld bead. It’s ideal for welding zinc-coated steel.

According to the manufacturer, this wire’s applications include tanks, repair work, earthwork, and steel building.

If you need more testimonials, I encourage you to give Amazon reviews a look. People seem to love it over there!

Forney 42300 Flux Core Mig Wire, Mild Steel E71TGS.030-Diameter, 2-Pound Spool, Silver, Pack of 1
2,358 Reviews
Forney 42300 Flux Core Mig Wire, Mild Steel E71TGS.030-Diameter, 2-Pound Spool, Silver, Pack of 1
  • All position flux core MIG wire for mild steel that is a self Shielded and works well on rusty, dirty and painted Material
  • Best suited to single pass applications with high travel speed, runs hotter than solid wires
  • Excellent for outdoor windy conditions
  • Click on the (BY FORNEY) name above in blue under the title to view our full catalog of Welders, Abrasives, Chain/Wire Rope, Tools and more!

Pros

Cons

I decided to kickstart the top product’s list with Forney’s flux core for one reason; its unmatched tensile strength.

Forney’s manufacturers claim it’s excellent for outdoor welding in windy conditions. True to their claim, I faced no difficulty using this core in my open workspace. Feeding it into the welder was smooth with minimum spatter. Despite being a self-shielded wire, I felt the urge to put some shielding gas on, but this is a wrong practice, so I’d take a point away for that.

You’ll find that this wire runs hotter than solid wires. Hence, it’s more suitable for single run welds. You don’t want to use this wire if your application requires multiple passes. It’ll produce an inconsistent, kind of lumpy weld.

Among its applications are assembly welding, railroad repairs, and light construction work. Practically, it’ll work with any type of mild steel that can be weld using a MIG welder. Furthermore, it works perfectly with applications that require high speeds.

Forney can weld up to 18-gauge metals, and even thicker ones. You don’t need to change your wire for welding different materials.

I’d have to tell you, this is a controversial product. It works smoothly only on perfectly clean surfaces. Do not expect it to work on an unprepared surface or you’ll encounter some crappy welds.

Blue Demon E71TGS .030 X 2# Spool Gasless Flux Core Welding Wire
2,307 Reviews
Blue Demon E71TGS .030 X 2# Spool Gasless Flux Core Welding Wire
  • typical applications to include lap and butt welds on galvanized sheet metal
  • Repair of automobile sheet metal
  • joining of galvanized roofing sheet metal

Pros

Cons

Next on our list is the popular Blue Demon flux core wire. People are raving over it on Amazon, and I can’t disagree with them, but I think it’s rather the best pick for hobbyists.

This is a flux core that runs cleaner than most of its rivals. It has a distinct performance when it comes to galvanized steel. It also does a pretty good job of repairing automobiles’ sheet metals.

You’ll encounter the same issue of Forney’s wire here. Because it’s self-shielded, Blue Demon is intended to be used with single-pass welds, which limits its usage. Yet, it’s an all-position welding wire.

Blue Demon comes in three thickness options; 0.03”, 0.035”, and 0.045”. The 0.03” would fit nicely with most welders. It works perfectly with carbon steel sheets.
The best way to use it? The lap and butt-welding method, through which you can weld pieces of different thicknesses together seamlessly.

INEFIL ER70S-6 .035-Inch on 10-Pound Spool Carbon Steel Mig Solid Welding Wire
594 Reviews
INEFIL ER70S-6 .035-Inch on 10-Pound Spool Carbon Steel Mig Solid Welding Wire
  • Low spatter, High feedability, Porosity free, Good bead appearance, Easy to weld
  • Shielding gas is required: 80-percent Ar+20-percent CO2 or 100-percent CO2,All Positions, Single and multi pass welding
  • Mig solid welding wire for Carbon and Carbon-Manganese steels
  • Made in Italy from the finest quality materials using state of the art technology under highly respected labor conditions
  • Approvals: ABS, TUV, DB, DNV, LRS, RINA, GL

Pros

Cons

Here’s another core wire that welding machines love. It feeds smoothly to the welder all the while being well wound to the spool. Besides, it’s porosity-free and it produces minimal spatter. Who could’ve asked for more!

The appealing price made many welders who used this wire think it’s made in China, especially that INEFIL, the brand, isn’t that famous. Yet, it’s an Italian brand that produces quality products at minimal prices.

INEFIL’s flux core wire requires a shielding gas. According to the manufacturers, you can use 80% Argon +20% CO2 or 100% CO2. Unlike Forney and Blue Demon, you can use this for multi and single-pass welds in all positions.

It’s especially convenient for welding carbon and carbon-manganese steel.

While you probably won’t face problems with feeding the wire to the welder, you might notice that the way it’s reeled around the spool is a bit unusual. It didn’t cause me any problems, but some reviewers complained of tangled wire, though.

Sale
LINCOLN ELECTRIC CO ED030584 .035'NR-211 Fluxco Wire,Black
773 Reviews
LINCOLN ELECTRIC CO ED030584 .035"NR-211 Fluxco Wire,Black
  • Designed for MIG wire feed welders
  • Fast freezing characteristics and good slag removal
  • Produces quality welds in moderate wind conditions with no tenting
  • Occupational Health & Safety

Pros

Cons

Lincoln’s products are well known for their durability and high quality. This MIG welding wire is no exception!

This is a self-shielded welding wire that would work perfectly in windy situations. It works well with mild steel sheets and feeds well into the welder, making it portable and easy to use. Needless to say, this wire would work perfectly with a Lincoln welder.

Lincoln’s welding wire is available in 0.030” and 0.035”, you can choose what you want depending on your application. I have to be honest with you here. It does produce some slag, but it won’t take much effort to clean it up.

I love the fact that this wire has fast freezing characteristics. It’s super easy to use and clean after, which is a plus for someone as lazy as me!

The most annoying feature of this wire is that it has only one-sized one pound spool. Unless you’re doing a small repairing job, you’ll need more. So, you’ll have to switch midway, which is a bit of a hassle. If someone can reach out to the manufacturers, ask them for bigger spools, please!

The Verdict

If it’s up to me, I’d choose the INETUB flux core wire as my go to. It’s the most comprehensive one, it balances quality and affordability well, and in my opinion, it gives the best results. 

The Best Flux Core Wire - A Buyers Guide

Let’s start with a briefing about what flux core wires are, how to use them, and how to differentiate between their types.

What Is a Flux Core Wire?

While you typically need to use a shielding gas during MIG welding to protect your welding pool from contamination, a flux core wire solves this problem for you.
As the name implies, the flux of a core wire produces its own shielding gas when it melts. This way, you won’t need a shielding gas, and you’ll save a lot of time and effort.

When it comes to FCAW, flux core wires come in 2 types; gas-shielded and self-shielded. Both types encompass an inner flux of deoxidizers, this is the component that’s responsible for clearing out the welding contaminants.

You might’ve guessed it, gas-shielded flux wires do require an external shielding gas. On the other hand, self-shielded ones are self-sufficient, as I mentioned above, and they dominate the market for that reason.

Producing a clean weld without needing a gas shield is what makes self-shielded flux core wires ideal for outdoor use. Their applications include bridge construction work and shipbuilding. On the other hand, gas-shielded wires are mostly used in heavy equipment manufacturing and petrochemical piping.

Flux Core Wire vs. Solid Wire - What’s the Difference?

To set them apart, you can use two types of wires for welding, either a flux core wire or a solid one.

As I said before, a flux core wire has an inner flux that produces some kind of a bubble around the weld pool, then creates slag. Contrastingly, solid wires don’t produce these bubbles, so it’s mandatory to use a shielding gas to get a clean weld.

What Are the Benefits of Flux Core Wires?

  • They’re perfect for outdoor work, especially in windy conditions.
  • They can be alloyed to match different base elements.
  • They produce clean, strong welds.
  • They have high deposition rates, compared to solid wires.
  • They have the ability to weld thick metals.
  • They’re easy to work with.

Downsides of Flux Core Wires

  • They produce slag, which requires cleaning after you’re done welding.
  • They’re relatively more expensive than solid wires.

0.030 vs. 0.035 - What’s the Difference?

You’ll encounter these 2 numbers a lot when you’re searching for a flux core wire. They’re a measure of the welding wire’s diameter. You can look at it as the thickness of the rod.

The thickness difference impacts the required amperage of the welding machine. The thicker the rod, the more amperage it requires to work with. A thicker wire burns hotter than its counterpart.

Naturally, 0.035 flux core wires require higher amperage and can weld thicker metals, namely metal sheets with a thickness of 16 gauge and up. Not only that, but it also won’t work well for thinner metal sheets, here’s when 0.030 core wires come in handy.

It’s not rocket science. You need to know the thickness of the metal sheet you’re working with to decide which type of flux wires works best. 

For this exact reason, I don’t like the question of, “Which flux core wire is better, the 0.030 or 0.035?” because simply, each one has its own set of applications. 

You need to look at two things; the thickness of the metal sheet and your flux core welder itself. If your welder is 210v or below, and you’ll mostly be working with thin metal sheets, then you should go for the 0.30. However, if you use a 250+v welder with thicker metal sheets -say of a ¼ inch thickness-, the 0.035 is your guy.

Specifications Guide - What Do These Numbers Mean?

You’ll notice that there’s something that resembles a code next to the wire’s name. These symbols have meanings that I’ll be explaining below.

  • E – means that you should use the wire as an electrode. You feed it to the MIG welder through the nozzle.
  • T- means that the wire is flux core and self-shielded. I.e it doesn’t need a shielding gas.
  • GS – means that this wire is supposed to be used in single-pass welds only.
  • 1 – means that you can use the wire for all welding positions; vertical, horizontal, flat, and overhead.
  • 7 – means that the tensile strength of the flux wire is above 70,000 pounds per square inch.
  • 11 – means that it supports DC polarity and multipass welding.

Tips for Improving your Flux Core Wire Weld

Here are 3 things you can do for a cleaner seamless weld.

Watch out for Feeding Problems

Nothing is more annoying than interrupting your arc suddenly. This won’t only cause you some downtime, but it’ll result in a noticeable defect in your weld as well. 

The wire might clump into a ball at the tip of the welder, which we call a Burnback. It mostly happens due to a slow wire feed. To solve this, you should look for a flux core wire that feeds smoothly and runs fastly into the welder. I made sure to cover this in my chosen product recommendations.

I’d also advise you to maintain a good distance between the welder’s tip and the surface you’re working on to avoid a Burnback.

Dealing with Slag

A common problem that happens with flux arc welding is slag inclusion. It occurs when the slag resulting from the flux of the wire ends up inside the weld itself, trapped there, contaminating it.

To avoid this, make sure to maintain correct travel speed and angle. This is about 5-15 degrees when your welder is in a vertical position, and 15-45 degrees for the horizontal position. Try to maintain steady travel speed and clean up the slag between the welding turns.

Pay Attention to Penetration

You’ve got to be super careful here. If you’re using too much heat, you can end up with too much penetration that the weld material is dripping underneath the weld. Of course, that’s not what you want. In this case, lower the voltage range. Then, reduce the wire feed speed.

You don’t want to end up in a shallow penetration also. If you feel like your weld is shallow, gradually increase the voltage and the wire feed speed. To make sure you’re using the right technique, make sure to reach to the bottom of the groove.

Frequently Asked Questions

Can I use shielding gas with a self-shielding wire?

I know this is a logical way of thinking. Unfortunately, it won’t produce the best results.
In fact, it can lead to a bad weld, because when you’re stopping the chemicals of the wire’s flux from interacting with the air -through the shielding gas- they will contaminate your weld eventually.

Can I use a flux core wire with a MIG welder?

Yes, it’s totally okay to do that. There’s no need to get a special flux core welder to do the thing. A MIG welder will do just fine.

Do flux core wires work on galvanized steel?

The short answer is yes.

Whether its galvanized or zinc-coated steel, flux core wires will burn off the galvanization as you weld. You’ll see it in the form of burnt smoke and fumes coming off of your weld.

You’ll get the last speck of it when you clean up your welding slag. You just need to keep in mind that steel will be welded, but it won’t keep its galvanization.

Are Welder Generators as Noisy as Regular Ones?

Being engine-driven, they can be noisier than regular ones. That’s why they’re best for outdoor use where the noise won’t be a problem.

If you work at home, you’ll want to get a welder that has a noise suppressor. Like the Hobart Champion 145, for example.

Is the Duty Cycle Important?

A machine’s duty cycle is the time that the cycle of operation occupies at a specific amperage. The duty cycle of welder generators is measured as a percentage of 10 minutes.

Meaning, if your machine’s duty cycle is 30% at 150 amps, then you should use the machine for 3 minutes and let it rest for 7 minutes when using it at this amperage.

It’s not just important, it’s vital for maintaining your welder’s power. If you don’t rest the welder according to its duty cycle, you’re risking its engine wearing out.