Welding aluminium has some unique challenges that call for precision and expertise. In this in-depth guide, we’ll explore the processes of welding aluminium using the MIG, TIG, and stick welding processes. We’ll talk about the pros and cons of each method. Help you understand the difficulties that come with aluminium welding. And learn essential tips for effective pre-cleaning before diving into the welding process.

Precleaning Aluminum for Welding:

Aluminum’s sensitivity to contamination requires thorough precleaning before welding. Eliminating oils, paints, and moisture is key to avoid porous structures in the weld. Products like acetone or specialised aluminium cleaners are a great way to remove hydrocarbons. Plus, using a stainless steel brush dedicated to cleaning is a good mechanical removal for the oxide layer. You can also take a look at our in-depth precleaning article for more information here, Metal Surface Preparation for Welding Excellence

TIG Welding Aluminium:

TIG welding stands out as the best method for joining aluminium, offering precision and aesthetic appeal. The alternating current (AC) TIG process is essential for breaking down aluminium oxide during welding. Choosing the right tungsten electrode and filler metal, along with proper TIG welder settings, enhances the quality of aluminium welds. Another way get quality results is to use a Pulsed TIG welder and a foot pedal. This provides additional control when weldiing. 

MIG Welding Aluminium:

MIG welding is a more accessible option for aluminium welding. Not only is it better for those less skilled but it is also much faster than TIG welding. You’ll need to use a pure argon shielding gas and address the challenges posed by the aluminium.

MIG Welding Aluminium Challenges

The aluminum wire for MIG welding is too soft, so its possible to experience feedability issues if you use a standard MIG setup for welding steel. It’s necessary to either use a spool gun to MIG weld aluminum or to set your MIG welder’s wire feeding system for use with an aluminum wire.

Spray Transfer For Aluminum

It’s necessary to use a spray transfer to MIG weld aluminium. Essentially, this means that you need to get the arc to “spray” tiny aluminium filler metal droplets across the arc and into the joint. Unlike the short-circuit transfer used for MIG welding steel, spray transfer keeps the arc ignited at all times and significantly increases the metal deposition rate. To enter the spray transfer mode, you must set your MIG welder’s voltage and wire feeding speed to high settings according to the machine’s manual. 

Stick Welding Aluminium:

While stick welding aluminium is a good option for repairs, it does it come with some challenges, such as stick electrodes. To be able to stick weld effectively, you need to use special stick electrodes designed for aluminum. These rods have an extreme affinity for moisture, so if left out in the open, they are highly likely to become overly damp and useless. Next, don’t forget about your DC stick welder as this is also a vital part of the process, and careful attention to preheating is essential. Keep in mind that stick welding is best suited for thicker aluminium stock, as the process tends to run hot and may lead to burning through thin gauges. And remember that filling in the end crater  is a critical step in stick welding to prevent cracking.

Additional Welding Methods

There are even options out there for those who fall more in the middle ground when it comes to welding expertise. If you are a beginner looking for more of a challenge then explore the possibilities of double pulsed MIG welding for enhanced aesthetics. And if you want an even bigger challenge then why not try some Stick welding aluminium. Although, this should be reserved for specific scenarios due to its messiness and complexity. By mastering the intricacies of each welding method, you can confidently tackle aluminium welding projects with success.

Final Thoughts:

Although welding aluminium requires skill and precision, there are options for all levels of welders. While MIG welding is a recommended starting point for beginners, TIG welding offers superior results but demands more experience. It all depends on your level of experience and what you feel comfortable with.