Arc Welding 101: Thoriated tungsten and its alternatives

Q: In "TIG welding--An overview," you said you used 2 percent thoriated tungsten until you heard about the health risks. What are other options? Does cost vary significantly (not that cost should matter when it comes to health or safety)? My fabrication shop runs 14 gas tungsten arc welding (GTAW) booths for two 10-hour shifts, six days a week, and we use a lot of 0.09375-inch-diameter, 2 percent thoriated tungsten.

A: My research says you shouldn’t worry about contaminating yourself while welding, but you could inhale tungsten powder when grinding the point. One source didn’t indicate any health risks associated with thoriated tungsten, but any time I see the word radiation, I’m going to go way overboard on safety.

Brian Wise, a welding and metal fabrication instructor at Herndon Career Center, Raytown, Mo., sent me some good information about using 1.5 percent lanthanated tungsten as an alternative, which I sent to Matt. He looked into the costs and offered the following cost breakdown:

• 2 percent thoriated tungsten costs $1.02 each.
• 1.5 percent lanthanated tungsten costs $1.51 each.
• 2 percent ceriated costs $1.76 each.

”Welders seem to prefer the lanthanated over the ceriated,” McIntyre said. “A couple of them said sometimes it seems like the arc dances around from tungsten to workpiece in midweld with the ceriated, but [they] couldn’t tell a difference between lanthanated and thoriated, except it seemed like the lanthanated kept its point longer, meaning [fewer] trips to the sander to resharpen. One thing about the company I work for is safety [comes] first, and if it costs a few extra dollars but is safer, they are all for it.”

Thanks, Matt. I wish all companies felt that way!