Aluminium plays a vital role in industries throughout Australia, from construction and mining to automotive and marine. Its corrosion resistance, light weight, and electrical conductivity make it a versatile material. But when it comes to joining this metal, arc welding aluminium calls for a unique approach.
This guide walks you through the essentials of arc welding aluminium, from choosing the right welding process to understanding aluminium’s physical properties.
Whether you’re working with aluminium sheet, components, or structural frames, knowing how the welding process works can help ensure a reliable result and a great investment.
What Is Arc Welding Aluminium?
Arc welding aluminium is the process of joining aluminium parts using a high-temperature electric arc that melts both the base material and a compatible filler metal.
As the molten metals cool, they fuse into a solid, durable joint that maintains aluminium’s natural strength, conductivity, and resistance to corrosion.
Why Aluminium Requires Advanced Welding Techniques
Aluminium might look like a straightforward metal, but once heat enters the equation, it tells a different story.
Unlike steel, aluminium doesn’t just get hot; it pulls heat away from the weld zone rapidly. This means it demands more energy, more control, and a far more strategic approach to achieve a clean, reliable weld.
Then there’s the aluminium oxide layer: a tough, invisible film that melts at temperatures more than three times higher than the metal beneath it.
If left untreated, this layer can prevent proper bonding, compromise strength, and even lead to defects that aren’t always visible at first glance.
That’s why the right preparation, tools, and welder settings aren’t just helpful; they’re essential.
And when every millimetre matters, trusting the work to skilled professionals with hands-on experience makes all the difference. From surface prep to final finish, precision isn’t optional; it’s the key to performance.
Core Arc Welding Processes Used For Aluminium
Several arc welding processes can be applied to aluminium. Each has its advantages, depending on material thickness, application, and finish required.
Shielded Metal Arc Welding (SMAW)
Also known as stick welding, this method is typically used for steel. It can be useful in field repairs or when working in breezy conditions where shielding gas may be disrupted.
MIG Welding Aluminium
MIG welding aluminium offers good speed and is a go-to method for medium-to-thicker aluminium sections.
A spool gun is typically used to prevent feeding issues with the soft aluminium wire. The use of mechanical wire feeding allows for efficient and consistent welds across longer seams.
TIG Welding Aluminium
TIG welding is often chosen for its precision, especially with thinner aluminium. For a full breakdown of this process, explore our TIG welding aluminium guide.
Flux-Cored Arc Welding (FCAW)
Although less common, flux-cored options for aluminium exist. They’re useful in some industrial settings but generally require specific filler material and equipment settings.
Custom Aluminium Welding
Custom aluminium welding is used when standard techniques don’t meet a project’s specific requirements.
This approach is ideal for complex geometries, non-standard joints, or working with specific aluminium alloys.
It allows for greater flexibility with welder settings, filler material, and joint preparation, helping achieve reliable results tailored to the application.
What Makes Aluminium Welding Challenging?
At first glance, aluminium may seem simple to work with: lightweight, corrosion-resistant, and widely used. But beneath the surface, welding aluminium reveals a series of challenges that set it apart from materials like steel.
These aren’t obstacles; they’re reasons to be precise and to work with someone who understands the metal’s unique behaviour.
- The Aluminium Oxide Layer: Aluminium naturally forms an oxide layer that’s invisible to the eye but not to the weld. This layer melts at temperatures over 2,000°C, far above the 660°C melting point of aluminium itself. If it’s not properly removed with a stainless steel wire brush or specific cleaning tools, it can interfere with bonding and compromise weld strength.
- High Thermal Conductivity: Aluminium doesn’t just heat up, it moves heat quickly and unevenly. That means the heat you apply to one section may disperse before it can do its job. Managing this requires precise control, consistent heat input, and a steady hand to keep the weld pool stable.
- Low Melting Point: While its low melting point makes aluminium easier to melt, it also means it’s easier to burn through, especially with thinner material. This narrow margin demands careful technique, optimised welder settings, and the right filler metal to ensure strong, clean welds.
- Hot Cracking: One of the less visible but more serious issues is hot cracking, which can occur when the wrong filler material or technique is used. It often develops beneath the surface as the weld cools and can go unnoticed until stress is applied.
The key to avoiding it is proper surface prep, matched filler wire, and solid technical judgement from the start.
Aluminium VS Steel Welding
Welding aluminium and welding steel require different approaches.
- Welding steel is more forgiving because it doesn’t require as much surface cleaning and can withstand higher heat input without distortion.
- Welding aluminium demands more control. It requires a clean surface, careful heat management, and specific filler metal.
If you’re specifically interested in the TIG process for stainless steel welding, check out our full article on TIG welding stainless steel.
Surface Preparation: The First Step To A Quality Weld
Surface preparation is one of the most important factors in achieving a clean, strong aluminium weld, and we take it seriously.
Before welding begins, our team thoroughly cleans and prepares the aluminium to remove oils, debris, and the natural oxide layer on its surface. This level of detail helps prevent defects like porosity or cracking and ensures a more reliable result.
It’s a step that’s often overlooked, but never by us. Because in aluminium welding, the difference between a good weld and a great one often starts well before the arc is struck.
Choosing The Right Filler Material
Behind every strong, lasting weld is a filler material chosen with intention. And when it comes to aluminium, that choice can make all the difference.
Different aluminium alloys require specific filler wires or rods to ensure the weld matches in strength, flexibility, and corrosion resistance.
At our workshop, we assess your material type, intended use, and environmental exposure to select the right match, whether ER4045, ER5356, or advanced aluminium electrodes.
It’s not just about compatibility; it’s about performance. And getting it right from the start means fewer issues down the track, so you can have confidence in every weld, no matter the application.
How Shielding Gas Affects Weld Quality
In aluminium welding, shielding gas isn’t just a background player; it’s one of the key reasons your weld turns out clean, strong, and built to last.
Here’s how we get it right every time:
- Pure argon is ideal for most aluminium jobs, offering stable protection and clean arc performance.
- Argon-helium blends are used when extra heat or deeper weld penetration is needed for thicker materials.
- Precisely calibrated flow rates help prevent porosity and protect the weld pool from contamination.
- Every setting is intentional, from gas selection to delivery, ensuring consistent, high-quality results.
We obsess over the details so you don’t have to. In welding, the invisible choices often make the visible difference.
Welder Settings Matter More Than You Think
Behind every clean, durable aluminium weld is a carefully tuned setup, and getting the settings right can mean the difference between a strong bond and a costly rework.
We fine-tune every project based on:
- Material Thickness: Thinner aluminium needs extra care to avoid distortion or burn-through.
- Joint design And Weld Position: Different angles and access points call for tailored adjustments.
- Welding Method: Whether MIG, TIG, or stick, each process demands unique calibration.
- Filler And Shielding Gas: These elements must align with the welder’s settings to avoid cracking or contamination.
When you’re trusting someone to weld aluminium, “close enough” isn’t good enough. That’s why we take the time to get it exactly right, so your outcome is as strong as it looks.
Practical Uses For Aluminium Welding In Australia
Aluminium isn’t just lightweight; it’s built for performance. That’s why so many Australian industries rely on professional welding to get the most out of it.
Here’s where our expertise makes a measurable difference:
- Mining & Construction: Durable walkways, load-bearing platforms, and precision-fabricated parts that stand up to tough site conditions.
- Transport: Reliable welding for trailers, ute trays, and structural repairs, helping keep fleets moving efficiently.
- Marine: Welded aluminium for boats, pontoons, and saltwater-resistant fittings that hold up in harsh coastal environments.
- Manufacturing: Custom enclosures, machine frames, and lightweight components designed for strength, accuracy, and clean finishes.
Whether you’re building new or repairing old, we help turn aluminium into lasting results.
Signs You Might Need Expert Welding Services
Some jobs are too important to leave to chance, especially when precision, strength, or quality are at stake.
You may need professional aluminium welding support if:
- You’re Working With Structural Components: Even minor imperfections can lead to major failures. Expert welding ensures reliability, which is where it matters most.
- You’re Using Aluminium Alloys: Different grades behave differently. We match the process to the material, so you don’t risk costly mistakes.
- You Need Clean, Consistent Results: Experience makes the difference between “good enough” and professional-grade for cosmetic welds or tight tolerances.
- You’re Seeing Warping, Cracks, or Defects: Distortion and porosity aren’t just unsightly; they often signal a deeper problem that expert welders can fix.
- You’re Working With Thin Sheet Or Advanced Setups: Techniques like DCEP or pulsed TIG require the right equipment, settings, and hands-on skill.
When quality matters, partnering with experts saves time, materials, and stress, and helps ensure a better result, the first time.
Frequently Asked Questions
Can I weld aluminium with a stick welder?
Yes, but it’s less common. It requires aluminium stick electrodes and a higher level of skill to produce consistent results.
What’s the best welding method for aluminium?
The ideal method depends on the job. TIG and MIG welding are highly effective for aluminium across many industries.
In other settings, other techniques like laser or electron beam welding may also be considered. The key is choosing the right approach based on your project’s scope, tolerances, and application needs.
How do I clean aluminium before welding?
Use a stainless steel wire brush dedicated to aluminium only. Remove oils with acetone and scrub the oxide layer thoroughly before welding.
Do I need professional welding?
If your project requires strength, quality, or specific appearance criteria, or if you’re experiencing distortion or cracking, professional welding is the more reliable option.
Can you help if my welds keep cracking or look messy?
Absolutely. Poor welds are often a result of incorrect technique, settings, or filler material. We can troubleshoot the issue and rework it professionally to give you stronger, more consistent results.
What is the turnaround time for welding services?
Turnaround times depend on the scope and complexity of the project. We’ll provide a clear timeframe upfront and aim to complete every job efficiently without compromising quality.
Conclusion
Arc welding aluminium opens doors to light, strong, and corrosion-resistant results, but it’s not as simple as welding steel. You can achieve high-quality welds tailored to your industry’s needs with the right preparation, equipment, and technique.
If you’re looking to get started or want support with your next aluminium project, look for a team that brings practical experience, thoughtful planning, and professional service to every weld.
Ready to take the next step? Contact Star Sheetmetal today at (03) 9000 0280 or 0433 217 574 to learn how we can assist with your aluminium welding project in Melbourne, from precision welds to large-scale structural work.
References
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Pfaller, A. (2024, February 7). Aluminum TIG Welding Settings: What You Need to Know. The Welder. Retrieved July 18, 2025, from https://www.thefabricator.com/thewelder/article/arcwelding/aluminum-tig-welding-settings-what-you-need-to-know
Samiuddin, M., Li, J.-L., Taimoor, M., Siddiqui, M. N., Siddiqui, S. U., & Xiong, J.-T. (2020). Investigation on the Process Parameters of TIG-Welding Aluminum Alloy Through Mechanical and Microstructural Characterization. Defence Technology, 17(4), 1234–1248. https://www.scribd.com/document/728943844/Investigation-on-the-process-parameters-of-TIG-welded-aluminum-alloy-through-mechanical-and-microstructural-characterization
Stick Welding Aluminum. (n.d.). Welding Tips and Tricks. Retrieved July 18, 2025, from https://www.weldingtipsandtricks.com/stick-welding-aluminum.html
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