Note: The opinions expressed in this post are solely those of the author.
Years ago, when I was still an apprentice at Chrysler, 2 percent thoriated (or “red”) tungsten was still the electrode pretty much everyone used, at least for DC welding. Over at the training center, instructor Tom Soley had me try out some lanthanated and ceriated tungsten. He explained to me how fears of radiation coming from the red tungsten had led the welding industry to look for alternatives. In his opinion, it was unnecessary. So I experimented with them, but neither kept a sharp point for long, and I quickly went back to the tried-and-true red. Nobody has time for electrodes that fracture or quickly dull. Tungsten Carbide Plates
To me, 2 percent thoriated always has been the best all-around electrode, period. It lasts the longest, holds the sharpest point, and has the strongest arc.
When I first tried those other alloyed electrodes, it was near the beginning of the industry’s search for alternatives. Tom had told me that basically every other electrode was attempting to “be” red, and that’s something that I took to heart. Why use a wannabe when you can use the original?
Heck, I even skipped the pure tungsten (green), and used red while welding aluminum on AC with the transformer-based Synchrowave 350 we had in our shop. Green is softer and balls up easier for AC welding aluminum, but it doesn’t handle heat as well. I preferred having tungsten that wouldn’t split at heat as opposed to one that balled up quickly.
While a lot of our disdain for the alternatives and loyalty to red was anecdotal and not very scientific, the reasoning seemed sound. Red electrodes stay sharp for so long and are so hard that there’s no way they can give off anything significantly harmful to breathe in during the welding process or to absorb while handling.
We thought perhaps breathing in the dust might be an issue, but joked that “unless you’re snorting it,” you probably wouldn’t get enough into your body to cause problems. And we all knew enough old-timers who didn’t get cancer to make it seem an unlikely culprit.
Steve Higley of the “Rate my Weld” page on Facebook sent a message to me a few months back, asking my opinion on TIG electrodes. I basically replied with a condensed version of what I’ve written here. A bit later he sent me an article from TWI (The Welding Institute) in the U.K., which basically (and scientifically) agreed with my opinion.
According to the article, “There is almost no release of radioactive material during arcing,” and “a welder holding an electrode for a whole year [receives] a very small fraction of the maximum permissible radiation dose, and it is concluded that the external radiation hazard is likely to be negligible.”
In fact, the only real danger in using 2 percent thoriated comes from—as we figured—inhalation of dust during grinding: “During the grinding process, particles of tungsten may be produced with thoria on the surface. It is these dust particles that create the major hazard, as they may be inhaled, and the thoria may release alpha particles from the surface.” Even so, “the risk of cancer in TIG welders due to thoria exposure is very low, since the exposure times to individuals are invariably small,” the article reported.
Left to right, ceriated (orange), lanthanated (grey), 2 percent thoriated (red). Photo courtesy of Brown Dog Welding.
So why is it increasingly harder to find 2 percent, and why do so many manufacturers refuse to produce it any longer? Because, even with the danger being so small that it’s nearly nonexistent, especially when proper safety precautions are taken (like don’t breathe in grinding dust), they fear being liable. Often there are other hoops to jump through, too, as in some places it’s considered a hazardous material. And in their eyes, there are completely nonradioactive options. That last bit is frustrating to me.
Nonwelders typically are the ones telling us we have “viable alternatives.” Granted, these days the lanthanated and ceriated tungsten electrodes are way more refined than they were even just 10 years ago. And some inverter-based welding machines (like the Miller Dynasties I use) are said to be fine-tuned to their arc characteristics. And to be honest, not every welder can tell the difference or will even push their electrode hard enough to notice. But I can, and I do. For my money, I still get the best results from 2 percent thoriated, and in my shop I’ll continue to use it as long as I can get my hands on it.
The Welder, formerly known as Practical Welding Today, is a showcase of the real people who make the products we use and work with every day. This magazine has served the welding community in North America well for more than 20 years.
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