It is possible to weld aluminum with a regular MIG (Metal Inert Gas) welder, but there are some important technical considerations that must be taken into account.
- Power source: In order to weld aluminum with a regular MIG welder, the machine must be equipped with a power source that is capable of producing a high-frequency output. This is necessary to create the necessary arc to start the weld.
- Wire feeder: The wire feeder on the MIG welder must be capable of providing the necessary wire feed rate and voltage to ensure a consistent, stable arc.
- Gas flow: In order to prevent oxidation and protect the weld from contamination, a shielding gas that is suitable for welding aluminum must be used. Argon is the most commonly used shielding gas for welding aluminum.
- Welding gun: A welding gun that is equipped with a gas lens and collet that is suitable for aluminum welding must be used. This will help to focus the gas flow and provide a consistent arc.
- Welding wire: A welding wire that is specifically designed for aluminum welding must be used. The most common wire for welding aluminum is 4043.
- Technique: Welding aluminum requires a specific technique, it’s important to use short arc welding and maintain a close distance between the electrode and the workpiece.
It’s important to note that welding aluminum is more challenging than welding steel, and requires a higher level of skill, and specialized equipment. It’s advisable to consult with experts or professionals and to practice scrap aluminum before attempting to weld aluminum in a production environment.
In this article, I’m going to dive into each of these 6 areas when it comes to welding aluminum with a MIG welder and what the best practices are to make it work.
#1 What Type of Power Source Should You Use for Welding Aluminum
When welding aluminum with a MIG (Metal Inert Gas) welder, a specific type of power source is required in order to create a stable arc and achieve a high-quality weld. The following are some technical considerations when it comes to the power source:
- Inverter-based power source: Inverter-based power sources are preferred for welding aluminum, as they are capable of producing a high-frequency output that is necessary to create the arc and start the weld. This high-frequency output also helps to prevent the electrode from sticking to the workpiece.
- Welding range: The power source should have a wide welding range, which allows the welder to adjust the output voltage and current to suit the specific aluminum alloy and thickness being welded.
- Stabilized welding voltage: The power source should have a stabilized welding voltage, which ensures a consistent arc and a stable weld pool.
- Constant current output: A constant current output is preferred for welding aluminum, as it allows the welder to maintain a consistent arc and a stable weld pool.
- Pulse welding capability: Some advanced power sources have a pulse welding capability, which is useful for welding aluminum in thin sections where a high heat input is not desirable.
- High open-circuit voltage: A high open-circuit voltage (OCV) is needed when welding aluminum, as it ensures a stable arc and prevents the electrode from sticking to the workpiece.
It’s important to note that welding aluminum requires specific settings and equipment, it’s important to consult the welder’s manual and follow the manufacturer’s recommendations for welding aluminum.
A power source that is not suited for welding aluminum might not provide the necessary high-frequency output, welding range, or other features that are needed for welding aluminum.
#2 Wire Feeder
When welding aluminum with a MIG (Metal Inert Gas) welder, a specific type of wire feeder is required to ensure a consistent and stable feed of the welding wire. The following are some technical considerations when it comes to the wire feeder:
- Wire drive rolls: The wire drive roll should be made of a material that is resistant to wear and corrosion, such as Teflon, as the aluminum wire is softer than steel wire and can wear out the wire drive roll quickly.
- Wire feed speed: The wire feed speed should be adjustable, as different aluminum alloys and thicknesses require different feed speeds. A higher wire feed speed will provide a wider and more fluid weld puddle, while a lower wire feed speed will provide a narrower and more controlled weld puddle.
- Tension: The wire feeder should have a tension adjustment, as too much tension can cause the wire to break, while too little tension can cause the wire to birdnest or bunch up.
- Gun liner: A gun liner that is specific to aluminum welding should be used, as it helps to guide the wire and prevent it from getting jammed or tangled.
- Burnback control: Some wire feeders have a burnback control feature that allows the welder to set the distance between the contact tip and the workpiece, preventing the wire from sticking to the workpiece once the trigger is released.
- Wire size: The wire feeder should be able to handle the specific wire size of the aluminum wire being used.
It’s important to note that the wire feeder plays an important role in the aluminum welding process, therefore, it’s important to use a wire feeder that is specifically designed for aluminum welding and to follow the manufacturer’s recommendations for adjusting and maintaining the wire feeder.
#3 What Kind of Gas Do You Use for MIG Welding Aluminum
The most commonly used gas for welding aluminum with a MIG welder is a mixture of argon and helium, known as “Ar/He.”
This type of gas mixture is preferred due to its high thermal conductivity and low reactivity, which helps to prevent oxidation and promote a smooth, stable arc.
Additionally, the helium component of the mixture can help to increase the penetration and width of the weld, resulting in a stronger, more durable bond.
Other gases that can be used for aluminum welding include pure argon or argon-helium blends, but these are less commonly used due to their higher cost and lower performance.
#4 What Kind of Welding Gun Do You Use for MIG Welding Aluminum
When welding aluminum with a MIG welder, it is recommended to use a gun that is specifically designed for aluminum welding. These guns typically have a larger diameter contact tip and a smaller gas lens to accommodate the different properties of aluminum wire.
Additionally, they may have a higher amperage rating and a different drive roll configuration to handle the softer and more malleable aluminum wire.
The gun should also have a liner made of Teflon or other high-temperature materials, as aluminum welding generates more heat than steel welding.
The gun should also be made of aluminum or other non-ferrous metals to prevent contamination of the weld by iron. The gun should have a push-pull mechanism to feed the wire more smoothly and consistently.
Additionally, it is important to ensure that the gun is equipped with a gas diffuser that can provide a consistent and stable flow of the Ar/He gas mixture to the weld area, as well as a proper nozzle that can direct the gas to the optimal location for shielding the weld.
Overall, the gun should be designed for high-performance welding of aluminum and should be equipped with the proper components to ensure a smooth and consistent weld.
#5 What Kind of Wire Do You Use for Mig Welding Aluminum
When welding aluminum with a MIG welder, it is recommended to use aluminum welding wire that is specifically designed for MIG welding.
The most common type of aluminum welding wire is 4043 alloy, which is a general-purpose alloy that can be used for welding a variety of aluminum alloys. The wire can be made with a variety of thicknesses and diameters, with the most common being .030 inches and .035 inches up to .045.
Another popular alloy is 5356 alloy, which is known for its high strength, good corrosion resistance, and good penetration. The wire of this alloy is also suitable for welding aluminum alloys that are thicker.
It is important to note that aluminum welding wire is softer and more malleable than steel wire, so it is important to use a drive roll and gun liner that are specifically designed for aluminum wire. Additionally, the wire should be stored in a dry place and kept free of oil and other contaminants.
Overall, the choice of welding wire will depend on the specific application, the thickness of the material, and the desired result. It is recommended to consult with the manufacturer’s recommendations and guidelines when selecting the appropriate welding wire for your project.
#6 Technique
When welding aluminum with a MIG welder, it is recommended to use the push technique, also known as “forehand welding.” This technique involves holding the gun at a 90-degree angle to the workpiece and pushing the gun forward toward the weld joint. This allows for better control over the weld pool and can help to reduce the risk of warping or distortion of the aluminum.
It is also important to use a lower amperage setting when welding aluminum, as aluminum has a lower thermal conductivity than steel. This can help to prevent overheating and warping of the material. It is also important to use a higher travel speed to prevent the weld from becoming too deep and wide.
Additionally, it is important to use the proper gas mixture, such as argon and helium (Ar/He), to shield the weld and prevent oxidation. Proper gas shielding is critical when welding aluminum as it prevents the aluminum from being exposed to air, which can cause oxidation and porosity, leading to weak and porous welds.
Overall, the proper welding technique for aluminum welding with a MIG welder involves using the push technique, lower amperage settings, and a higher travel speed, as well as proper gas shielding to prevent oxidation. It is also important to use the right wire and gun that are specifically designed for aluminum welding.
