Flux Core Aluminum Welding Wire, I Want It Now

By Bill Byers / June 15, 2019

You have a great 90 Amp or 130 Amp flux core welder and it uses flux core welding wire.

But you have this little job to do and the base metal is Aluminum.

You ask, ‘Can you weld Aluminum with a flux core welder?’

In reality your question is ‘Can you flux core weld Aluminum?’ And ‘Can you weld using flux core aluminum welding wire?’

What you really, really want is a spool of Aluminum flux core wire.

And you want it now.

Your Google Search

Your Google Search

You’ve searched online and it has led you here.

Your search for flux core Aluminum welding wire on Google will have shown you a bunch of adverts.

With welding wires that claim they are Aluminum flux core welding wires. Or say they are gasless aluminum MIG wires.

Others are reels of solid Aluminum MIG wire when you look up close. And you know your gasless flux core welder can’t use that.

Cause that stuff needs Argon gas.

You search and search. You start to question whether there is such a thing as flux core Aluminum welding wire?

In your quest some of the wires look tantalizingly like what you want.

But the stark truth is that none of them are suitable for welding Aluminum with your flux core welder.

And if you do use that stuff then you’re going to need new welder soon.

As the best case is that the wires won’t weld at all. And in the worst case they stuff up your flux core welder.

The Unicorn… the Holy Grail of MIG Welding

Is flux core Aluminum welding wire a unicorn? That mythical creature searched and searched for.

The answer is Yes.

Gasless flux cored Aluminum wire for your flux core welder exists only in the imagination.

So why does the rumor of its existence raise its head every few years?

The Truth About Aluminum Flux Core Wire

You’ll find that even when the welding wire says flux core in the ‘title’ a closer inspection reveals:

1. It is solid Aluminum wire and the small print says Argon gas recommended. Actually it’s more than recommended it is crucial.

And what’s more you’re going to need a MIG welder that uses gas. i.e. the wire is for MIG welding not gasless flux core welding at all. Or

2. It is soldering wire. Again a process that has nothing to do with MIG welding or flux core welding. Or

3. It is Aluminum wire, flux core yes;

  • but the wire is for brazing machines. Brazing machines have an automatic wire feed.
  • Or the wire is for use in a furnace where the air supply is tightly controlled.
  • Or for use in an induction brazing process.
  • Or it is wire for use with a propane gas torch or a torch that produces a flame. All this means it isn’t MIG wire but brazing wire. So what? You’ll find an explanation further below.

Where Can I find Flux Core Aluminum MIG Welding Wire for Sale?

And I get why you are searching for this unicorn.

You have a $100-$300 flux core only welder because you wanted to get into welding. Or you only had some small mild steel welding jobs to do.

Your budget didn’t stretch to a more expensive MIG with gas.

And now you have just this bit of Aluminum welding and you don’t want to pay someone else to weld it for you.

But there are good reasons why there is still no sign of this unicorn.

No Flux Cored Aluminum Welding Wire For Sale

There is a great article from The Fabricator.com by Frank Armao of Lincoln Electric on the subject. Frank Armao was cited in the article as being a member of several relevant American Welding Society committees.

The article dates from 2013 and is still valid today.

The points he covers in that article are;

1. The American Welding Society (AWS) has no standard for flux cored Aluminum wire. Here is a link to the standards page for you to double check if things change. It is unlikely.

2. The fact is, that the flux chemicals in common use for steel MIG welding do not work for Aluminum. Aluminum is too reactive with air.

3. There was some laboratory tests of fluxes that did work for Aluminum. But laboratory tests and moving to commercial products are two very different things. Why?

4. The reason the process is difficult in the real world. Is that in the real world, outside of the laboratory, there are many things that need controlling. Aluminum is reactive. So finding a chemical shield that is effective as a flux for flux core welding is a huge problem.

5. The shielding chemicals used in the lab are corrosive – not exactly what you want for your weld. They suck up water from the air. This means that storing your Aluminum flux cored welding wire would be a problem.

Image yourself opening your Aluminum flux core welding wire. Then a few short minutes later you find your welding wire contaminated and useless. That would be beyond upsetting.

And you would need strict storage conditions for your flux core aluminum wire. Otherwise your weld joint would be poor, porous and fail.

6. On top of all that, the flux core chemicals that work in the laboratory are a disaster to the environment. And who wants that.

Here is a link to the article:

There is no such thing as flux cored Aluminum welding wire for sale and for good reason. It doesn’t exist.

So what options do you have for welding Aluminum?

Can You Use ‘normal’ Flux Core Welding Wire to Weld Aluminum?

The short answer is no. You can’t use steel based flux core wire in your FCAW welder to weld Aluminum.

It just won’t work. And you won’t get the join you’re expecting.

You may burn out your welder. The Amps needed to weld Aluminum is more than a basic 90 Amp or 130 Amp welder is capable of generating.

The splatter produced would be mind blowing. It would clog up your contact tip and could even short out your welder.

And after that you’d have no weld or one that failed.

No point trying that one.

Welding Aluminum Without Gas? What are your Options?

Aluminum Soldering

The only method out there that possibly uses no gas at all is soldering.

But even in the various methods of soldering you’ll find a propane gas torch. It’s used to melt the solder material into and onto the joint.

There are limits to the use of a soldering iron to weld Aluminum. Because a soldering iron can’t generate enough heat. Well not enough to create a firm joint of any significant size.

The Aluminum joint needs to be extremely clean. As any contaminants can cause your solder not to stick. Particularly as Aluminum is so reactive with air.

But at least there is no gas involved in this process if you decide to solder with a soldering iron.

Aluminum Soldering with a Torch

There is a difference between soldering a joint with a flame torch and brazing.

In soldering, the solder – the filler material – melts at a lower temperature compared to brazing wire.

The Aluminum base metal is heated but not melted. The Aluminum solder flows into a small gap between the Aluminum joints.

Aluminum Flux Core Wire for Brazing

In brazing the Aluminum filler material melts at a higher temperature. But it is important to understand that the joints are still heated up but not melted as in arc welding.

Flux core Aluminum welding wire for brazing is not designed for use in an electrical arc. Flux core welding uses an electrical arc.

Brazing Warming the joint

Brazing Flame Torch Warming the joint. Picture Credit: Lucas-Milhaupt

Brazing uses a gas flamed welding torch. Not a MIG torch.

The joint has the flame of the welding torch held near. The aim is to heat the Aluminum enough so the flux core Aluminum wire for brazing melts. But not so much that the Aluminum base metal melts.

Brazing Filler Flow

Brazing Filler Flow. Picture Credit: Lucas-Milhaupt

A brazed joint needs to be scrupulously clean. Particularly when you are joining Aluminum. If the joint is dirty, you can file. The alternative is to clean with chemicals.

You bring the Aluminum joints together.

And by close together I mean a gap of 0.0012 to 0.024 of an inch. This is so that you can get enough flow of the filler material into the gap to make the join. And also for joint strength.

Finished brazed joint

Finished brazed joint. Picture Credit: Lucas-Milhaupt

Gasless Aluminum Welding wire, Is There such a Thing?

Outside of soldering with a soldering iron and for the reasons above no.

Aluminum needs gas to weld. Whether it is in the brazing process where you use a torch and with flammable gas to heat the joint. Then flow the brazing Aluminum filler metal into the joint.

or in MIG or for TIG welding where Argon gas protects the hot metal from the air.

Because of the reactive nature of hot Aluminum it is all to easy to spoil your join with contaminants in the air.

MIG or TIG Welding Aluminum

MIG and TIG welding uses electricity and Argon shielding to protect the joint from the air. MIG and TIG uses an electrical arc to melt the base metals and the filler material. So that they all merge and flow together and that forms your weld.

Welding Aluminum, Your Options are:

1. The best option and easiest option is to get yourself a MIG welder. One that is capable of feeding Argon gas and welding Aluminum . And what I mean is that you need a MIG capable of generating enough amperage to weld Aluminum.

Plus the MIG welder needs a spool gun. A spool gun feeds the Aluminum MIG welding wire.

2. The prettiest option for Aluminum welding is to use a TIG welder. Those skilled in the art of TIG welding make the best looking Aluminum welds.

You TIG weld when the join is visible and it’s important that it looks good. TIG welding is a slower process than MIG welding and demands skill and practice. But I suspect that if you’re doing this search you’re no TIG welder.

Because you would have TIG welded the repair already.

3. The next possible option is a MIG welder capable of generating enough power. No spool gun only a normal MIG gun and a Teflon liner.

Argon gas is still needed to shield the weld from the air. A Teflon liner helps the wire to slide through the hose and up to the MIG gun. Because it is ultra smooth and offers less friction to the soft Aluminum MIG wire.

To feed the Aluminum MIG Wire;

  • Lay out as flat and as level as possible the cable or hose to the MIG gun. That way you get the best feed of the Aluminum MIG wire you can.
  • Adjust the tension rollers of your MIG’s wire feed. You want the wire griped but not crushed.
  • Your MIG welder’s polarity changed for welding with Argon gas and solid Aluminum wire. And it is possible.

YouTube Video MIG Welding Without a Spool Gun

This 15 minute video takes you through the issues, and some of the solutions. Unfortunately it doesn’t show you a successful weld but it does show you what can happen and often does.

Tips for MIG Welding Aluminum without a Spool Gun

Video Credit: Weld.com

Aluminum is a soft metal. You can end up bending the Aluminum inside the hose. Because you are feeding from the wire feeder in your MIG welder, through 10 foot of cable to the torch head. Resulting in non existent or poor wire feed.

Birds Nest of Wire

Birds Nest of Wire

Second YouTube Video MIG Welding Aluminum without a Spool Gun

This next video 7 minute video not only covers the issues, it shows some welds. It’s a bit rough and ready but does show you how it can be done.

How to MIG Welding Aluminum without a Spool Gun

Video Credit: A21bravo

No Spool Gun Weld Results

No Spool Gun Weld Results

The welds aren’t pretty and will need grinding to smooth off but he got a weld.

4. If you’re desperate and have a stick welder to hand.

I found this video from WeldingTipsandTricks. He compares using a stick welder or a TIG welder with Aluminum flux stick rods. If you find yourself in a tight spot and that is all the equipment you have available….

Again, works, but its not pretty and there are issues with the joint with some porosity using the sticks.

Aluminum Stick Weld Porosity

Aluminum Stick Weld Porosity

Preheating helped.

Aluminum Stick Weld Preheat

Aluminum Stick Weld With Preheat

but if you are stuck in a jam it’s a way through.

YouTube Video Stick Welding Aluminum

Here is the complete just under 4 minute video to take a look at

Stick Welding Aluminum

Video credit: weldingtipsandtricks

To Close

The Unicorn of flux core Aluminum welding wire does not unfortunately exist. Even if you want it now.

I hope my article has shown you some of the options available for welding Aluminum.

Interested in looking at welders capable of MIG welding Aluminum? Why not check out the Lincoln 140 MIG welder or the Everlast 140 iMIG articles I have on the site.

 

Click here to add a comment

Leave a comment: