TIG welding aluminum requires tungsten as an electrode. But the tungsten comes in several variations from pure to some percentages of rare earth metals. So, if you don’t know what color tungsten for aluminum to use, you can’t even start the welding process.
Pure tungsten comes in green color, and it can be used only in DC. The same goes for red-colored 2% thoriated tungsten. You can use orange-colored 2% ceriated tungsten for welding aluminum in AC. But for both AC and DC, you need to use the blue-colored 2% lanthanated and the gold-colored 1.5% lanthanated tungsten. There’s another tungsten which is 0.40% zirconiated (brown), and it can be used in AC.
Tungsten preparation includes choosing tungsten types for getting better results in welding. Otherwise, it would be a mess.
Table of Contents
- Why Tungsten Color Matters for Aluminum Welding?
- Which Color Tungsten Should You Choose?
- Steel Variations
First of all, tungsten just doesn’t come in pure form. It has several variations based on the mixture with rare earth metals. That’s why those several combinations show different colors in reality.
Therefore, if you know what combination each color indicates, you can identify the perfect tungsten electrode while welding aluminum. And luckily, there’s a TIG welding tungsten color chart that describes each color identification for tungsten.
Before starting welding, you need to find the proper tungsten electrode. In several variations, it’s pretty hard to find a specific tungsten type.
Read more : Best tungsten for aluminum
That’s why you need to follow the tungsten electrode chart that contains every color and combination of tungsten. So, let’s take a look at them individually:
The orange tungsten electrodes contain 98% pure tungsten and 2% cerium on average. These types of electrodes can be best used in AC only.
However, you can also use the orange tungsten electrodes in low current settings of DC welding. It shows low amperage of arcs that make it pretty popular for use in pipe fabricating, orbital tubes, thin metal sheets, and other delicate parts of metals.
It has similar characteristics to thoriated tungsten. So you may not be able to tell the difference. But we don’t recommend using it in high amperages because the metal oxide might quickly migrate excess heat.
2% Lanthanated (Blue)
The blue-colored tungsten comprises 2% lanthanides and 98% pure tungsten. These types of tungsten electrodes are best for both AC and DC. Therefore, you won’t have to worry about the power supply.
Another advantage is that the blue-colored tungsten can create pretty lovely arcs. The electrodes have a low burn-off rate, making them more efficient than other types.
1.5% Lanthanated (Gold)
The gold-colored tungsten electrodes are made of 1.5% lanthanides, and the rest is pure tungsten. It’s known for good arc stability, lower burn-off rate, and impressive re-ignition characteristics.
It can replace thoriated tungsten because of similar conductivity. This gold tungsten is also ideal for both AC and DC. The electrodes can maintain any sharpened points while welding aluminum and stainless steel.
It can maintain a lower arc in lower voltages during the welding. Surprisingly, the gold tungsten has a maximum current capacity of 50% of its size.
Pure Tungsten (Green)
The pure tungsten comes in green color. These electrodes have more than 99.5% tungsten in their composition. And that’s why they have the highest consumption rate compared to other electrodes.
These electrodes are famous for balanced waves and excellent arc stability in AC welding. The balled tips are pretty clean and seamless on magnesium and aluminum. So, what is green tungsten used for?
Well, because of its higher stability and performance, it’s used in carbon steel, aluminum, stainless steel, and many other powerful weldings. However, we don’t recommend using it in DC because the arc won’t be strong enough.
2% Thoriated (Red)
The red-colored tungsten mainly contains 2% thorium, and the rest is tungsten. The percentage may vary from 0.5 to 0.8. It’s by far the most popular electrode today.
Red-colored electrodes are known for their ease of use and longevity. These electrodes have a higher electron emission rate that provides higher arc capacity. But it works below its melting temperature.
The thoriated electrodes cause fewer welding contaminations compared to others. You can use the red tungsten electrodes on DC and, occasionally, in AC. The sharp edges help to provide smooth grinding.
0.4 % Zirconiated (Brown)
The brown-colored tungsten contains 0.4 to 0.8% zirconium. Though it’s not pretty popular, it can provide higher stability of arcs and can resist tungsten splitting. You can use it only in AC. The manufacturers strictly forbid using it in DC.
The steel has many variations, and the tungsten welding is different for each category. Let’s see how:
The red-colored 2% thoriated tungsten electrodes are best for welding steels. That’s because they can perform well in lower temperatures.
The thoriated tungsten electrodes are also ideal for mild steel. You can use lanthanated electrodes, but the stability won’t be excellent because mild steel melts in lower temperatures.
To put it simply, purple tungsten is for stainless steel. It’s also known as rare earth electrodes (truly non-radioactive alternative) that can replace the red tungsten electrodes. The purple tungsten has a higher performance ratio in all DC applications.
During welding with tungsten, you need to know some tips that may help to get better performance, smooth welding, arc stability, etc.
First of all, you need to choose the color of the tungsten electrodes based on your welding surface and your power supply. That’s because surface material is not suitable for every possible arc stability or temperature. And not all the tungsten electrodes can perform in AC/DC/AC-DC current.
It will be one of the biggest mistakes if you don’t know the color combination of tungsten electrodes and their properties before welding.
Hopefully, you have learned what color tungsten for aluminum while welding. Be careful of using these tungsten electrodes because of radioactivity. Work safely and ensure proper weld finish every time!
Hey this is Robert from Weld Gallery.
We have experience in welding for the last 5 years and I own a lot of welding equipment from different companies. We know good quality welding tools are very difficult for newbies and that is why we have created this blog to help the welding newbies and welders.