Historians like to reference ancient cultures based on their tool-making technologies. The Copper Age, for instance, ran from about 4500 BCE to 3300 BCE. Next came the Bronze Age from 3300 BCE to 1200 BCE. That was followed by the Iron Age from 1200 BC to 600 CE. So in historical terms, you might argue we’re living in the Aluminum Age, as the metal was first isolated only as far back as 1825.
Over the last 200 years, aluminum has quickly become one of the most important metals to industry and manufacturing. Its light weight and relative strength have made it ubiquitous in daily life. But one of the challenges with aluminum has long been how to weld it. Due to its high thermal conductivity and oxidation, early blacksmithing and forge-welding techniques were ineffective for joining aluminum.
A little over a century ago, engineers begin experimenting with gas welding (oxyacetylene) for aluminum. But they soon found controlling the heat to be difficult, making it impractical for structural applications. It wasn’t until the early 1940s that Russell Meredith, an engineer at Northrup Aircraft, developed a process for welding aluminum and magnesium. Originally called ‘Heliarc” welding, it used a tungsten electrode shielded by helium gas to stabilize heat and prevent corrosion.
This process was further refined by using argon gas, which we now refer to as aluminum TIG welding. For a long time, this was an expensive process limited to industrial applications. Today though, TIG welding is more affordable, making it the preferred method for even DIY welders working with aluminum.
TIG welding is, in fact, one of four different ways DIY fabricators can weld aluminum today. Below is a look at the ins and outs of each of these options and why you might choose one over another.
TIG Welding (GTAW – Gas Tungsten Arc Welding)
The current standard for welding thin aluminum, especially precision work like aerospace, automotive, and fabrication. Consumer-level TIG welders are more affordable than ever and there is good support in terms of shielding gas and consumables.
- Advantages: Produces high-quality, clean welds. Allows for precise heat control.
- Challenges: Requires more skill than other methods. Slower process compared to MIG.
MIG Welding (GMAW – Gas Metal Arc Welding)
An alternative to TIG welding, MIG works well for medium to thick aluminum, including some automotive and structural applications. Many modern MIG welders can be outfitted with a spool gun to feed aluminum wire. It still requires using the correct shielding gas, typically argon
- Advantages: Faster than TIG welding. Easier for beginners to learn. Uses a spool gun or push-pull system to feed soft aluminum wire.
- Challenges: Requires proper wire feeding setup. Not as clean as TIG; can require post-weld cleanup.
Stick Welding (SMAW – Shielded Metal Arc Welding)
Like other stick welding operartions, using this method on aluminum works best with heavy sections, primarily outdoor applications.
- Advantages: Can be used in windy conditions (no gas shielding needed). Works on thicker aluminum without extensive preparation.
- Challenges: Requires specialized aluminum electrodes. Not ideal for thin aluminum due to excessive heat input. Produces rough welds that may need post-weld machining.
Oxy-Fuel Welding (Oxyacetylene)
Yes, you can still weld aluminum with fire, but they technology (and results) haven’t changed much in a hundred years. This option is really best only when performing historical or repair work on aluminum.
- Advantages: Can be done with simple equipment. No electricity required.
- Challenges: Difficult to control heat, leading to burn-through. Rarely used for aluminum welding today.
Brushing technique is great , I would add that a very clean stainless steel brush will give you the best results. Any dirt or iron remnants will make for a poorer weld . Scotch Brite is also a better option than a dirty or regular steel brush.