This week we’re looking at tungsten electrodes. Which one is right for your TIG project and should you choose single-process tungsten or the popular dual-process electrodes? Read on as we look at these vital TIG consumables…
Making the right choice of tungsten electrode (‘tungsten’) is vital for successful TIG welding – in fact, they’re what gives TIG (tungsten inert gas) welding its name. But which of the available tungsten's should you choose?
Questions before TIG welding
Choosing the right tungsten is one of several considerations before TIG welding. The key questions include: What am I welding? AC or DC? Is my TIG welder transformer or inverter-based? What amperage do I need? And, last but importantly, which tungsten electrode to use, of what diameter, and should it be ball- or point-tipped?
Your parent metal determines whether you use AC (aluminium) or DC (steel) TIG process. Conventional wisdom has long maintained that single-process tungsten's work better with specific processes. However, just as all-season tyres can replace dedicated winter and summer rubber, so dual-process tungsten's can replace single-process electrodes. They bring real benefits and often outperform the latter. More later, but first, let’s look at the colour-coding that helps you identify tungsten.
Whether they’re pure tungsten, or alloys of tungsten, rare-earth elements and oxides, TIG electrodes have coloured tips for easy identification.
Although you can still get pure tungsten electrodes (green tip), alloying other materials with the tungsten adds benefits. In particular, getting the best from inverter-based TIG welding machines (such as our TIG161 AC/DC 160Amp Inverter TIG Welder) relies on tungsten-alloy electrodes. To be honest, using pure tungsten is pretty unusual. So which single- and dual-process tungsten do we usually encounter and how are they colour coded?
First, there are red-tipped 2% thoriated tungsten's for DC welding of all steels. And their single-process equivalent for AC TIG welding metals such as aluminium (white-tipped 0.8% zirconated tungsten). Whether by accident or design, red tips match the oxides associated with mild-steel and white matches aluminium oxide. Please don’t mistake white 2.4mm stainless steel filler rod for a zirconated tungsten and put it in your TIG torch. You laugh, but it happens!
Getting the best from inverter-based welders
Next, to dual-process tungsten's that work equally well with AC or DC – and often better than single-process electrodes! Three top sellers are grey (2% cerium oxide), dark blue (2% lanthanum oxide) and gold tipped (1.5% lanthanum oxide) tungsten's. There are others, with different-coloured tips. But from experience, ceriated and lanthanated tungsten's are the most common and versatile – we sell them every day…
So why use a dual-process tungsten when they cost a bit more than single-process electrodes? Understanding the benefits comes back to making the most of inverter-based TIG welders. Their advanced square-wave technology improves arc starting and arc stability. In turn, this gives better weld quality, faster travel and lower operating costs. Getting the best from these machines relies on; excellent arc striking, arc stability, current-carrying capacity, lower risks of weld contamination and extended electrode life of modern tungsten's. It’s a perfect match.
Dual-process for AC and DC TIG welding
Now consider how dual-process tungsten's perform well for a wide range of AC and DC welding. This brings the continued role of single-process electrodes into question, particularly with emerging health concerns about dust from thoriated tungsten's.
Remember too, that inverter-based welding machines enable use of smaller-diameter tungsten's for easier weld-zone access. You can also sharpen dual-process tungsten's differently at each end. That way you can have ball- (AC) and pointed-tips (DC) on the same electrode. Added convenience doesn’t stop at those tungsten ends either!
More convenience benefits
There’s another important convenience benefit. Why keep lots of different single-process electrodes? Instead, a few carefully chosen dual-process tungsten's let's you reduce how many consumables you buy and store. It’s like fitting those all-season tyres. Their performance is so good these days that few people notice any difference from dedicated seasonal tyres. Paying a bit more for dual-process tungsten's may be worth the modest premium if you get the best of two worlds in one product.
Okay, maybe your TIG methodology demands two different torches, one set-up for aluminium and one for stainless steel? If so, perhaps you’ll stick with your favourite single-process tungsten's.
Talk TIG tungsten's with our experts
Navigating all available TIG consumables – including tungsten electrodes – takes experience, knowledge and time. Choosing tungsten's is about much more than just composition; there’s diameter and amperage to consider too and everything must be just right if you’re to achieve good TIG welds. Just one thing out of place, be it a tungsten choice or gas setting, can undermine your hard work. Fortunately, whatever your reason for needing TIG tungsten's, we’re here with honest advice to help you choose.
Send us an email or call us sometime!