Can Mig Welder Weld Aluminum – An Expert Explains

When it comes to welding aluminum, it becomes way more complicated than any other metal you may have worked with. As the aluminum is a comparatively softer and lighter metal than other materials, which is way low in strength. You can easily manipulate it, forge it, and give it any type of form you want. That’s why working with aluminum and welders requires a very sophisticated work method.

It requires low-temperature yet a consistent welding flow to get an even and clean weld. Although you can use almost any type of welding solution to weld aluminum, it may require other measures as well. Among all the welding methods, MIG has a wide range of work areas, the question is, Can mig welder weld aluminum? Well, let’s find out if the MIG welding method can work on such a sensitive metal like aluminum.

Can Mig Welder Weld Aluminum – An Expert Explains 1

What Kind Of Welder Do You Need To Weld Aluminum?

As you know already, welding aluminum is a difficult job to pull off, several welding methods can do the job; such as:

  • MIG or the GMAW: The Gas Metal Arc Welding method, or the MIG welding method has a fast travel speed while welding. You have to use a gas shielding for welding aluminum with this method.
  • TIG or GTAW: TIG is the most regular welding solution for other metals; you can use it for aluminum as well. It’s a great way to weld aluminum as it doesn’t use the mechanical wire feeding.
  • Resistance welding: Welding aluminum is possible with Resistance welding, but it will be difficult due to the thermal conductivity of aluminum. You have to be very precise about setting the parameters for welding aluminum with Resistance.
  • Laser or Electron Beam welding: You can use the laser beam to weld aluminum, but the power density will be a problem since it uses light as its energy medium. For the electron beam, it’s less of a headache as it works inside a vacuum.

Can Mig Welder Weld Aluminum?

Aluminum is a sensitive metal that requires a tricky approach to weld with MIG welding. It’s thinner than other metal and prone to imbalanced heat, yet requires a higher voltage than mild steel. If the question is, Can mig welder weld aluminum? The answer would be yes, but with extra care. Here is what you should know about it and how you can weld aluminum with MIG welding:

Mind the thickness

To weld aluminum with the MIG welding method, you must get a piece of aluminum that has a thickness of 14 to 18 gauge. If you’re welding anything less than that, you will need the TIG welding method to weld thin aluminum pieces. If you try to MIG weld less than 14 ga aluminum, you might get a nasty burn through and ruin the pieces. Most of the time, the burn through happens because of a puddle too hot to stay on the bead. So, you have to be careful about travel speed and voltage as well.

Be careful about the travel speed

The travel speed of your mig gun defines how many puddles you’re leaving behind to join the metal together. For other hard metals, it’s the ideal option to go slow and let more puddle create a better weld on the bead. However, when you’re working on a piece of aluminum, it’s not the same, you have to go fast. The reason behind that is, you cannot leave too much puddle behind the travel as you might too much. Too much puddle will burn through the aluminum, so you have to practice fast travel. But, be sure to leave enough filler to join the pieces with the right process.

Use the right welding process

As we know, MIG welding has four different welding types, and pulsed spray transfer is one of them. In most of the cases of welding aluminum, you’ll be using this method for the best output. You’ll spray the tiny filler aluminum on the molten puddle to join the pieces. Before that, it will make a short circuit to melt the puddle into the joint. The spray particles go onto that puddle, so you have to use the right manufacturer suggested voltage on that. Nonetheless, you must get the best welder for aluminum to get the capability onboard.

Gas mixture for protecting the weld

We use two different types of gases with MIG welding for different types of welding solutions. For example, when welding mild steel, closest to aluminum, we use 25% of Carbon dioxide and 75% of argon gas. However, for MIG welding aluminum, you must use 100% Argon gas to shield the molten puddle. The argon gas is ideal for helping the spraying transfer occur correctly on the puddle. For the thicker aluminum, such as 0.5″ or more, you have to use helium gas as well. The amount of helium will vary from 25% to 75%, depending on the thickness and weld penetration.

Get the right spool gun

To perform the MIG welding on an aluminum surface, you must use a spool gun with a wire feeding roll. Although you could use a filler rod with other metal and skip a spool gun, you can’t do that with aluminum. The reason behind that, it requires a consistent speed, and aluminum wires are too soft to hold still and consistent. For that same reason, you need to have a special gun for aluminum with the spool feed on the tip of the gun. If you try to use a regular mild steel gun, the aluminum wire will consolidate while it travels through the gun hose.

Polarity and direction

Before you start welding, you have to set your polarity correctly and use the MIG gun in the right direction. Unlike most of the MIG welding projects, you have to use the Direct Current Electrode Positive (DCEP) for welding aluminum. Setting this reverse polarity positive will help you get the weld to come out of your gun. For the direction, you have to use the push direction for aluminum with a 25° forehand push angle. It will get you a nice and clean weld if you keep your hand steady and consistent.

Advantages Of Mig Welding

MIG welding comes with a lot of advantages compared to other welding methods, especially if you’re a beginner. Here are the most important Advantages of MIG welding that you can look forward to:

  • Easy to learn: MIG welding is deliberately easier than any other welding method, and it takes only a few hours to learn it through if you’re a beginner.
  • Free from slug: with gas shielding, The MIG welding method doesn’t produce any slag to protect the weld. So you don’t have to chip off the slags later after you’re done with the weld.
  • Affordable consumables: The consumable electrodes are pretty much cheap in most cases when you’re using MIG welding. So, you don’t have to spend a ton on the consumable wires.

Frequently Asked Questions

Here are the most frequent questions about the MIG welding for aluminum that you should know about:

Is it difficult to weld aluminum?

Yes, it’s a bit difficult to get started with, but you’ll get fluent once you get used to it.

Can you weld aluminum with a MIG welder without gas?

No, most of the time, you have to use 100% argon gas to protect the mold while welding aluminum.

How many amps does it take to weld 1/4 aluminum?

You’ll need 200 amps to weld ¼ aluminum to get the maximum penetration and better weld.

Final Thought

Welding aluminum is always a hectic job, especially if you’re using MIG welding to get the job done. You must use the right MIG welder to make the most out of it, so you have to get the right MIg welder as well.

Once you have the right welder, go through the process I’ve mentioned above to weld your aluminum pieces together. You have to practice a lot with the MIG welder to get the answer to the question, Can mig welder weld aluminum? I hope you have the right guideline to weld aluminum with a MIG welder.

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