Practical Welding Today - May/June 2009

B The MacArther Maze project, initially estimated to take six months, was completed in three thanks to the Stinger Welding Inc. crew.

Building the bridge

to anywhere

Bridge fabricator dares to be different,
and succeeds

not uncommon to see the welders using a SAW unit out in the field.

Typically, bridge fabrication and shielded metal arc welding (SMAW) go hand-in-hand. But at Stinger, SMAW is not the process of choice. Instead, FCAW makes up 80 to 90 percent of the welding done in the shop and on the job site.

“We’ll take along a generator with constant voltage and a suitcase welding unit with wire feeder and gas bottles and crane those up wherever we need to weld. I’ve heard a few DOTs come by and say, ‘We’ve never seen anybody do this before. You erect with flux-core?’ Yes, we do. You can go up and X-ray it or ultrasonic test it and it will pass.”

There are times when SMAW is the obvious choice, Gardner explained, such as in a tight spot where the welder can bend the electrode to reach around a corner. But for heavy structural applications in which the welds have to be really good, Gardner said SMAW doesn’t make sense.

“It’s very slow and it’s more difficult to control your electrode. With FCAW we almost always get really high-quality welds with very little rework. We can sleep at night because we know we’ve put up something good.”

To say that Stinger Welding Inc. is unique could be considered an understatement. After all, the AISC-certified fabricator of bridges and bridge components from Coolidge, Ariz., prides itself as a team whose very livelihood is to fabricate, piece together, and erect components that hold human life in the balance. And given the projects the company has taken on—and the way in which they were carried out—who would be brave enough to dispute them?

Up and running since 1996, Stinger Welding has asserted itself as a fabricator to be reckoned with in the Southwest. Home to approximately 100 welders, the company— best known for its ability to complete projects quickly—has found success because of the quality of its work force and the commitment given by each individual, said Gary Gardner, quality assurance/quality control manager and CWI for Stinger.

“One of the things I really love about this place is we’ve got a very good work force,” Gardner said.

“It starts with the people in production. If they’re not completely committed to this, there’s nothing that quality control can do to fix that. No matter how hard you inspect something, you’re not going to turn something bad into something good. It has to come from the grass roots.”

Working Fast,

Maintaining Quality

Stinger’s commitment to completing projects quickly does not mean the company sacrifices quality. Everything is built to quality requirements specified by codes and beyond, explained Gardner.

“We’ve got a very low defect rate coming out of this place.”

Part of the reason that the quality of the welds has been so good, according to Gardner, is the processes the company leans heavily upon. The company chooses to use flux-cored arc welding, gas metal arc welding with metal-cored wire, stud welding, and submerged arc welding (SAW) for the larger pieces. In fact, it’s

MacArthur Maze

In 2007 a gasoline tanker overturned on California Interstate 880, caught fire, and destroyed two spans of the overpass bridge on Interstate 580 near Oakland. The California Department of Transportation (Caltrans) immediately put the bridge reconstruction project out to bid for this span of highway— known locally as the MacArthur Maze—that handles in excess of 150,000 vehicles a day.

“The tanker accident had immediate and far-reaching effects on the local economy. Traffic had to be rerouted, other construction projects were delayed, and public transportation was terribly overloaded. Caltrans initially estimated it would take at least six months to complete the reconstruction,” Gardner explained.