Can You Weld Aluminum With a MIG Welder? Answers Explained

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Welding Buddy Experts

June 19, 2021
can you weld aluminum with a mig welder

Suppose you’re trying to improvise a new object out of a couple of soda cans or trying to fix broken aluminum furniture. These tasks will require a proper welding job for completion. Whether you’re a beginner or a professional, it is not always an easy task to do. 

Now you’re trying to find the best welding option to work on an aluminum workpiece and decided on MIG welding for aluminum. But can you weld aluminum with a MIG welder? Some people ask such questions because aluminum is quite a tricky material to work on. We have this question answered in essential discussions below.

Why Welding Aluminum Is Challenging

What makes aluminum difficult to weld? As typical and ideal as the material is, being used for various equipment, there are traits about aluminum that make it tough to work on. Here are some of its challenging factors:

High Thermal Conductivity

This characteristic makes aluminum more vulnerable to unwanted distortion, burn-through or cracking during the welding process. It disperses the heat fast and has a low melting point, so it can blow through quickly if the welding arc is too powerful.

Fast Oxidation

Aluminum contains an oxidized layer, which helps resist corrosion. However, this trait that is considered an advantage also makes the welding process more challenging. You are required to clean the aluminum object(s) thoroughly before you can start welding.  

Pleasing Visuals, But A Bit Displeasing for Welding

The appearance of aluminum is what makes it ideal for creating consumer products, mostly tech gadgets. The silvery shade of aluminum makes objects look sophisticated, and the material is also lightweight and robust. However, the color is pretty tricky when you’re trying to see if it’s ready to work on when it comes to welding.

Sensitive to Impurities

Aluminum is sensitive material, making it more easily contaminated with air or water particles. Poor shielding and unmatched arc lengths can increase the risk of contamination. Water issues cause moisture, and air reduces the material’s strength. It is indeed essential to clean the aluminum workpiece thoroughly before you begin welding it.  

Let these factors be beneficial to your welding knowledge instead of discouragement. Of course, everything is challenging initially, but you can figure your way out of doing this job well!

MIG Welding: An Overview

MIG or Metal Inert Gas welding is a process where you fuse metals using electricity. It is a decade-long prominent arc welding process for both professional and hobbyist welders because it is versatile and easy to learn. Its technical name is Gas Metal Arc Welding (GMAW) and a slang called wire welding, but MIG is the most commonly used term. 

It works with a wire electrode that is continuously fed and heated in a weld pool through a welding gun. The gun sends a shielding gas to prevent the weld pool from getting contaminated.  

MIG welding works with different metals: stainless steel, carbon steel, magnesium, copper, bronze, aluminum, nickel, and alloys.  

Valuable Tips on How to MIG Weld Aluminum

Our answer to the question, “can you MIG weld aluminum?” is an absolute yes! However, before you begin, you need to know some essential information to ensure a successful weld. We have it all covered from preparation to completion below.

Getting Started

To prepare for the MIG welding aluminum process, you need to have the right tools. The proper equipment will protect you from any harm and will ensure a productive welding session. Check out some valuable tips and procedures below:

Cleaning the Aluminum

For a material like aluminum, thorough cleaning is essential to prevent air and water contamination. Use acetone to remove any signs of grease, oil, or water vapor on the aluminum’s surface. Remove oxides on the surface with a stainless steel bristle wire brush. Remember to rinse the aluminum properly and maintain it fully dry. Since it can be easily contaminated, clean the joint and cover it when not in use.  

Wearing Safety Gear

You can’t start welding without protective gear. Find the most reliable welding equipment: welding helmets, welding gloves, welding jackets, safety glasses, and more to protect the entire body. These equipment differ in welding type, size, and special features. Look into those important details closely when picking the right set of MIG welding safety apparel.

Welder Type

Not all welding machines work for aluminum. Experts recommend going for either MIG or TIG welders to work on the workpieces. Can you weld aluminum with a flux core MIG welder? No. Aluminum requires more amperage than the usual, which is around 90 to 130. Can you weld aluminum with a gasless MIG welder? No. Exterior shielding gas (preferably argon gas) is required for aluminum, and this welder doesn’t provide that. The shielding gas and welding wire are essential factors in aluminum welding. 

Aluminum Thickness, Spool Gun, and Shielding Gas

The thickness of the aluminum plays an essential role because there’s a technique that only works for materials around 14 gauge to 18 gauge. Thinner ones will require TIG welding. 

Choose the right shielding gas as well. For non-ferrous metals like aluminum, you will need a 100 percent argon gas with 20 to 30 cubic feet per hour of flow rates. 

Lastly, you will need a spool gun. A spool gun can prevent birdnesting (tangling of wires) and improve the stability of an arc. Note that some welding machines do not allow spool guns, so ensure you get one compatible with guns. 

Welding Techniques

There are specific ways of operating MIG welding you can apply exclusively for aluminum workpieces. Knowing these techniques will determine the outcome and enhance your skills further. From the right angles to the exact welding speed, keep these things in mind when you try to MIG weld:

  • A 10 to 15-degree angle: A basic rule for MIG welding aluminum is to push at a 10-15 degree angle and no pulling. A pulling or dragging angle will only increase the risk of particle contamination.
  • Use spray transfer method: This is a smooth transfer of tiny aluminum particles sprayed into the weld pool. Increase the voltage and adjust the gas mixture setting. Be careful because this method uses a massive amount of heat and penetration. It would help if you checked the thickness of the aluminum. The spray transfer method is not recommended for materials thinner than 14 gauge. 
  • Weld fast and in one pass: Welding at a fast travel speed is a way to avoid the possible blow through or distortions of aluminum. As much as possible, weld in a single pass to avoid a cold lap (molten metal that can’t entirely fuse with the cold plate surface and produces a small crack). 

Conclusion

The question “Can I weld aluminum with a MIG welder?” has been answered. Yes, you can, but it can get a little tricky, so take note of the right ways to do it. We hope this article helps you conduct a safe and successful aluminum MIG welding procedure, whatever application that may be.

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