MIG Welding Aluminium: The Definitive Guide for Welding Enthusiasts


Updated: 22 Nov 2023

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MIG welding is an essential process in the welding journey when you want to do a project of joining different types of metals. The MIG welding aluminum is a unique challenge in the welding industry.

The process of MIG welding aluminium is complex compared to mild steel. We will share all the MIG aluminium guides and insights every welder needs.

You need to understand the role of the shielding gas, wire selection, and other fundamental aspects of the MIG welding aluminum. Whether you are a beginner or an experienced welder, you can improve your welding skills, ensuring high-quality and successful welding projects.

Table of Content
  1. MIG Welding Aluminium & Its Working Process:
  2. Optimizing MIG Welder Settings for Aluminum Welding
    1. Wire Type and Size
    2. Comparison Table of Welding Wires 4043 and 5356:
    3. Gas Selection
    4. Wire Feed Speed
    5. Voltage Setting
    6. Travel Speed
    7. Torch Angle and Technique
    8. Cleanliness
    9. Gas Flow Rate
    10. Polarity
  3. Push Vs. Pull in MIG Welding Aluminum: When to Choose
    1. Pushing the Weld (Push Technique)
    2. Pulling the Weld (Pull Technique)
  4. Choosing the Right Gun and Wire Feeding for Aluminum MIG Welding
    1. Welding Gun Selection
    2. Wire Feeding Systems
  5. Why Welding Aluminum Presents Unique Challenges
  6. Essential Steps for Pre-Weld Aluminum Cleaning in MIG Welding
    1. Removal of Oxidation:
    2. Tackling Contaminants:
    3. Surface Roughening:
    4. Teflon Liner and Drive Rolls:
    5. Wire Quality:
    6. Clean Welding Gun and Nozzle:
    7. Clean Surroundings:
  7. Essential Safety Gear for MIG Welding Aluminum: Protecting Welders
  8. Troubleshooting MIG Welding Aluminum: Common Issues and Solutions
    1. Burn-Through (Melt Through)
    2. Poor Penetration
    3. Irregular Bead Shape
    4. Cracking or Brittle Welds
    5. Dirty Welds
    6. Excessive Spatter
    7. Inadequate Shielding Gas Coverage
  9. FAQs:
  10. Final Verdict

MIG Welding Aluminium & Its Working Process:

mig weld on aluminium
MIG Welded Piece of Aluminum
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MIG welding aluminum is also called Metal Inert Gas welding, which is a welding process whose primary focus is to join alloy and aluminum by utilizing a MIG welder. This one is the best welding option for joining aluminium materials.

When you join something using this welding method, it will be a strong and durable weld. If we talk about the MIG welding aluminum, the welder uses the electrode wire, which is made of aluminum or alloy fed through the welding gun.

If you want to protect the weld pool from atmospheric contamination(introducing unwanted foreign materials), release the shielding or argon gas. The welding arc between the electrode and the workpiece generates the heat needed to melt the aluminium material, causing it to melt as it solidifies.

During MIG welding aluminium, you need to follow these essential factors.

Factors to Follow During MIG Welding Process

During MIG welding aluminum, you need to follow these essential factors.

  • Shielding Gas: Are you looking for a clean weld? It’s essential to use a suitable shielding gas for a clean weld. There are different types of shielding gas, but the most usually usable gas is the combination of pure argon or helium-argon.
  • Wire Selection: It’s essential to choose the aluminum wire and ensure it matches the type of aluminium you are welding. Different MIG welding wire options, such as 4043 and 5356 aluminum alloys, are available in the market.
  • Cleanliness: The aluminum is susceptible to contaminants, so cleaning the base materials is essential.

You can use aluminium MIG welding in different projects. It joins the aluminium materials strongly and aesthetically pleasing welds.

Optimizing MIG Welder Settings for Aluminum Welding

Before doing a MIG welding aluminum project, it’s essential to do proper setting, which is the key to completing your project smartly. The correct setting is necessary to ensure a strong and reliable weld.

There are specific setting adjustments for the MIG aluminum welding. Here are a few key considerations.

Wire Type and Size

MIG Welding Aluminium Wire
Aluminum Wire for MIG Welding
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Using the aluminium welding wire that matches the workpiece alloy is recommended. The most common options available in the market are 4043 and 5356 wires. Make sure that the diameter of the wire is suitable according to the material thickness.

Comparison Table of Welding Wires 4043 and 5356:

ER4043ER5356
Smooth Bead, Good WettingBlack Smut, Distinct Ripples
Low Column StrengthBest Feedability
Higher PenetrationLower Penetration
Lower DuctilityHigher Ductility
Much Lower Shear StrengthHigher Shear Strength
Lower Melting PointHigher Melting Point
Lower Cracking SensitivityHigher Cracking Sensitivity
Narrower Melting RangeWider Melting Range

Gas Selection

Choosing a suitable gas is essential while doing a MIG welding aluminum project. You have two options: pure argon or the helium-argon mix, the most recommended gas for the MIG welding aluminium.

Use 100% pure argon while welding upto a 1/2 inch thickness of aluminium, which is approximately 12 mm, but if it is more than 1/2 inch, then more energy is required to melt the material. In this case, use the gas mixture of argon 75% and helium 25%. If you want to prevent contamination, then make sure that the gas should be of high purity.

Wire Feed Speed

Compared to steel MIG welding, a higher wire speed is required for aluminium welding. You can adjust the wire speed according to the wire diameter and the welding machine’s recommendations. If you are looking for the exact setting, then it would be better to consult the welding machine’s manufacturer.

Voltage Setting

The voltage setting can be adjusted depending on the wire diameter and material thickness. If you have thicker aluminium materials, then it’s recommended to use the higher voltage setting for it.

Aluminium Electrode Diameter (mm) InchesShielding GasTransition Current
(0.8) 0.030100% Argon90 ± 5 Amps
(0.9) 0.035100% Argon110 ± 5 Amps
(1.2) 0.045100% Argon135 ± 5 Amps
(1.6) 0.062100% Argon180 ± 5 Amps

Travel Speed

If you maintain the travel speed, then it will ensure to keep the proper heat distribution. If the travel speed is too slow, it may lead to excessive heat. If it’s high, then it may result in insufficient penetration. Make sure to keep it maintained and check it again and again.

Torch Angle and Technique

Make sure you hold the gun at an angle of 10-15 degrees, with the wire pointing in the direction of travel. You can use the pushing welding technique, which keeps the moving gun away from the weld pool.

Cleanliness

The aluminium is sensitive to impurities(Unwanted substances in the weld), so it would be better to clean the workspace free of contaminants. You can use the brush to clean the surface perfectly.

Gas Flow Rate

You can adjust the gas flow rate according to the manufacturer’s recommendations, which is between 20-30 cubic feet per hour (CFH). Do you want to prevent oxidation? Make sure you are using the right shielding gas flow.

Polarity

If you want to reduce spatter(Molten metal droplets during welding) and are looking for better arc stability, then using the electrode positive (EP) is recommended.

These are the general settings according to the welding expert’s recommendations. You can check the welding machine manually on the different settings according to the specific project.

If you do the correct MIG welding settings, then it will ensure a high-quality, reliable, and strong weld.

Push Vs. Pull in MIG Welding Aluminum: When to Choose

push vs pull welding technique
Push Vs. Pull Welding Process
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During MIG welding aluminium, you might need clarification about which technique to use. It depends on the several factors of pull or push technique when to use. Here are a few key considerations when using the pull or push technique during aluminum MIG welding.

Pushing the Weld (Push Technique)

push welding technique example
Push MIG Welding Method
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  • The push technique is recommended if you want to do welding in the flat and horizontal positions.
  • It’s recommended for fast travel speed.
  • This is the best option, producing fewer spatters and contributing to a cleaner environment.

Pulling the Weld (Pull Technique)

  • The pull technique is the best option when you want to do welding overhead.
  • It will result in deeper penetration, a suitable option for high-stress joints.
  • If you are looking for deep penetration, such as thicker materials.

The decision on that pull or push technique is to be used on several factors. Both have their pros and cons. Here, we just shared short information. You can read the article about the pushing and pulling technique on our website for detailed information.

Choosing the Right Gun and Wire Feeding for Aluminum MIG Welding

When it comes to the MIG welding aluminum, choosing the right gun and feeding gun option is essential for high-quality results. Here are some key considerations.

1. Welding Gun Selection

  • Spool Gun: For MIG welding, an aluminum spool gun is the most popular choice. The spool gun is specially made for aluminum wire, providing excellent control. You can connect the spool gun to the welding machine through a cable, which is more flexible, and you can easily handle the gun.
  • Push-Pull Gun: The push-pull gun has a more precise wire-feeding control. Do you love welding with a longer gap between the wire feeder and the gun? The push-pull gun is the best option. The push-pull gun is specially used for thicker aluminum materials.

2. Wire Feeding Systems

  • Standard Wire Feeder: The standard wire feeder is used for the MIG welding aluminium but may require additional accessories. It needed special drive rolls to help you with the soft aluminum wire. It’s a bit costly, but it’s the best option if you want to weld the aluminium frequently.
  • Aluminum Feeding Kit: Some welding machines have aluminum feeding kits with all the necessary parts, such as Teflon liner and U-groove drive rolls, which help you easily feed the aluminium wire.
  • Synergic Control: This is the best option I love, and you can use it as a beginner. The synergic control has pre-programmed settings for the aluminium welding. It simplifies welding by automatically adjusting the wire speed and voltage according to welding materials.
  • The decision between a wire feeding system and a welding gun depends on several factors. If you are a professional welder, spool and push-pull guns are ideal options.

Why Welding Aluminum Presents Unique Challenges

Welding aluminium is quite complex compared to other metals. There are several reasons why welding aluminium is difficult. Let’s dive into it in detail.

Aluminium has a high thermal conductivity, which produces heat more quickly. During welding, it’s difficult for you to maintain the heat for the weld pool. The aluminium has oxidation susceptibility(corrosion risk).

When you expose the aluminium to air, it forms an oxide layer on its surface. Before welding, remove this layer because it can lead to contamination. The melting point of the aluminium is lower than the other metals.

Do you need to become an expert in managing the welding project quickly? Sometimes, it may result in the material becoming molten faster, burning, etc. If you are welding the aluminium pieces, it’s susceptible to hot cracking when you want to weld the thicker section.

It would be better to select proper filler materials and use expert techniques to prevent cracking issues. The aluminium expands and contracts significantly according to the temperature change. Sometimes, during welding, it leads to distortion(caused by welding heat) and wrapping.

Aluminium is difficult to handle because it’s soft and ductile. The aluminum alloy adds complexity to the welding process, so you have well-known knowledge about it.

Some aluminiums have magnesium, and the proximity of the other materials, such as steel, etc, can lead to galvanic corrosion.

If you have a successful aluminium weld, you must learn the proper welding techniques. Ensure you have special equipment, such as a spool gun, and good knowledge about the aluminium alloy you are welding.

Essential Steps for Pre-Weld Aluminum Cleaning in MIG Welding

oxidation layer on metal surface
Oxide Layer on Metal Surface
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If you want to ensure a successful and high-quality weld, then cleaning the aluminium surface before MIG welding is the crucial step. Here are some key considerations for cleaning aluminium as the best option for welding.

Removal of Oxidation:

Aluminium forms an oxide layer quickly when you expose it to the air. If you want a clean weld, then you need to remove this layer. Using the chemical cleaner or stainless steel wire brush, you can eliminate the oxide layer.

Tackling Contaminants:

The aluminum surface has contaminants such as oil, dirt, or grease. It would be better to clean it using special aluminium cleaning products, which help you eliminate these impurities.

Surface Roughening:

Whire Wheel for cleaning stainless steel
Use Wire Wheel to Clean the Oxide Layer
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The aluminium has a smooth finish, which makes it challenging for the weld to penetrate. You can use a wire wheel with a clean pad to roughen the surface and improve the weld quality.

Teflon Liner and Drive Rolls:

If you are using the MIG welding aluminum technique for your welding project, make sure to use the Teflon liner and U-groove drive rolls. It will prevent jamming and tangling when you are working with soft aluminum.

Wire Quality:

Ensure aluminum welding wire is free from contaminants. If you properly keep the wire in safe storage and handle it, it will prevent issues during the welding.

Clean Welding Gun and Nozzle:

It’s recommended to clean the welding gun and nozzle daily. It will prevent the spatter and ensure a high-quality weld.

Clean Surroundings:

Make sure to keep the welding area environment clean. It will ensure a high-quality weld. Keep the welding area from dust, dirt, and debris.

Sometimes, the cleaning process may depend on the specific welding conditions of the aluminium and welding machine. You can follow the best practices and manufacturer recommendations for cleaning aluminium in MIG welding.

Essential Safety Gear for MIG Welding Aluminum: Protecting Welders

When MIG welding aluminum, it involves high heat, potential hazards, and intense light, so safety is essential to keep yourself protected from it. Here are some safety equipment you should consider before welding.

mig welding safety precautions
Safety Precautions
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  • Welding Helmet with Shade 10-13 Lens: A welding helmet comes with a variable shade lens that can be adjusted to 10-13 levels, giving good protection against intense arc light. While purchasing the helmet, make sure that it’s specially designed for MIG welding.
  • Welding Gloves: The welding gloves are made from leather materials, protecting you from sparks and burns. Make sure to purchase gloves specially made for welding.
  • Welding Jacket: Most people ignore the welding jacket during MIG welding aluminum, but experts believe it’s a better option to protect your upper body from heat and sparks.
  • Welding Apron or Bib: Do you want to protect your lower body and legs? The apron or bib will provide additional protection against your body and legs.
  • Welding Cap: A welding cap is the best option to protect your head and hair from sparks. You can wear any cap that covers your head and hair completely.
  • Safety Glasses or Goggles: You must wear safety glasses to protect your eyes from particle debris. If you don’t have specific glasses, you can wear any glasses covering your eye completely.
  • Ear Protection: People don’t use these things for ear protection, but the welding noise can sometimes damage your ear. This is why earmuffs or earplugs are recommended to help you prevent hearing damage.

Safety is the priority, while MIG welding aluminum helps minimize the risk of injury.

Troubleshooting MIG Welding Aluminum: Common Issues and Solutions

This troubleshooting guide will help you identify the common problems and how to troubleshoot all of the issues. Let’s dive into it in detail.

Burn-Through (Melt Through)

Cause: When you overheat the base materials too much, it may cause burn-through or melt-through.

Solution: It would be better to increase the travel speed and shorten the welds. You can spread the heat when you move on to the different parts. If you are facing a thorough problem, try to weld the thicker materials to combine the two pieces. During welding, make sure to eliminate the gap between the materials.

Lower the voltage and wire feed speed for the thinner materials.

Poor Penetration

Cause: It sometimes causes inadequate heat.

Solution: The best solution is to increase the voltage and wire feed speed to help you achieve better penetration.

Irregular Bead Shape

Cause: If you run the welding machine at an inconsistent travel speed or torch angle results in an irregular bead shape.

Solution: To reduce this problem, it is recommended to maintain the travel speed and keep the torch at a consistent level.

Cracking or Brittle Welds

Cause: The hot cracking can occur due to inadequate preheating and post-welding cooling.

Solution: If you are welding thicker aluminium in the welding project, then it is recommended to maintain the proper preheating and post-welding cooling procedure.

Dirty Welds

Cause: The weld will appear dirty or porous.

Solution: Many people use a drag technique, sometimes leading to a dirty problem. This is why it’s recommended to use the push technique. Clean the base’s metal properly with a stainless steel brush or other cleanliness items. Make sure to use the proper alloy and type of wire alloy and shielding gas.

Excessive Spatter

Cause: When using the incorrect wire feed speed, voltage, or the contaminated workpiece.

Solution: You need to adjust the wire feed speed and voltage. Make sure to keep the welding environment clean from the spatter.

Inadequate Shielding Gas Coverage

Cause: If there is an insufficient gas flow, some problems occur in gas coverages.

Solution: While welding, you need to ensure the correct gas flow rate because an unbalanced gas flow may lead to gas dispersion.

FAQs:

Can you MIG Weld Aluminium without Gas?

Mig welding aluminum required inert gas shielding. There are different gas shielding choices, but the most common options are pure argon. The shielding gas is essential to prevent oxidation and ensure a clean, reliable, and strong weld.

Can I MIG Weld Aluminium with the same equipment I use for Steel?

The MIG welding aluminium requires a specialized tool such as a spool gun, which helps you to handle the soft aluminium wire and provides better control over the welding project. Some of the MIG welders can be used for both aluminium and steel.

What type of Shielding Gas should I use for MIG Welding Aluminium?

Pure argon or argon-helium mix shielding gas is used for MIG welding aluminium. The choice depends on your specific project and the welding conditions. If you use 100% argon gas, it has the benefit that it can also be used for TIG and MIG welding aluminium.

Final Verdict

MIG welding aluminium is an essential and versatile process used in various industries. It has aluminum properties, which is why it has some unique challenges. It has high thermal conductivity and susceptibility to oxidation.

To achieve a successful aluminum MIG welding, you must have the proper knowledge, skills, and equipment. Choosing the suitable shielding gas, wire diameter, and welding gun is crucial.

If you want to overcome the challenges associated with MIG welding aluminium, then it’s essential to understand the wire feed settings, voltage, and proper welding techniques. Make sure to know when to use push and pull welding techniques.

What type of project have you used the MIG welding aluminium? And how was your experience with it? Let us know in the comments section below. It will help our readers.


Abu Bakar

Abu Bakar

Hello, Abu Bakar here, the Mastermind Behind Welding Villa. Test my years of experience through my well-written blogs, where I have covered the overall experience of welding materials and shown all the aspects of Welding, their types and equipment.

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