SECOND TIME AROUND IS A CHARM
By Mike Russell
This structural fabricator had tried a certain brand of MIG consumables years before and didn’t think they were the right fit for their application. But, after keeping an open mind and agreeing to a second trial, their reduced downtime and costs eventually led them to convert all of their MIG guns and consumables over to that brand.
When you have a company that fabricates its projects by the tons and measures its man-hours by the thousands, downtime simply isn’t an option. The welding operators and supervisors at Brooklyn Iron Works (Spokane, WA) know that fact better than most. This company, whose steel fabrication spans from bridges in Alaska to projects in Antarctica, tackles some of the highest-profile, high-inspection jobs around. And they rely on some good old-fashioned teamwork, among other attributes, to meet their deadlines.
“Everything we do is a team effort,” quality assurance manager Phil Zammit explains. “We’re a good company with skilled employees and good management. It makes us a premium company here in the Northwest.” It also makes them a reputable one. Brooklyn Iron Works doesn’t maintain a sales force, but instead relies — and successfully so — on its reputation and word of mouth to generate business. Scott Allen, the company’s general manager, explains that they are invited to bids based simply on the quality work they do and the timeliness in which they do it.
Last year, Norco Gas & Supplies (Spokane, WA) representative Tim McGrath approached Zammit and Allen with a proposition to make their welding operations even better: a two-week trial of Centerfire™consumables from Bernard (Beecher, IL) on their existing MIG guns. According to Zammit, they had tried Bernard products years before and didn’t think they were the right fit for their application. Still, he decided to keep an open mind and agreed to the trial. Two weeks later, he invited McGrath to convert the front-end of all 25 of the company’s MIG guns to Centerfire consumables and shortly thereafter, converted to Q-Gun™ MIG guns too.
The reason? Less downtime.
THE PROJECTS AND CHALLENGES
Brooklyn Iron Works, according to Allen, fabricates projects ranging from 650 tons up to 2,000 tons or more, including fracture critical structural components for bridges, demand-critical welding on columns, beams and moment connections bound for seismic locations, like California. Not surprisingly, the company maintains a workforce of highly skilled certified welders certified to the AWS D1.1 (Structural Welding Code – Steel), D1.8 (Structural Welding Code – Seismic) and D1.5 (Bridge Welding Code).
Many projects take between nine months and a year from start to finish. Depending on contract and/or code specifications, every weld at Brooklyn Iron Works is visually inspected and oftentimes includes 100 percent NDE (nondestructive examination), including MT, UT or RT. Others undergo random NDE testing for quality monitoring purposes. The company maintains a staff of certified welding inspectors (CWIs), as well as hosting contracted NDE inspectors, to manage these tasks. They also have a cleaning and painting facility to finish products after welding and prior to shipment to customers.
Gaining access to the weld joints is one of the biggest challenges welding operators at Brooklyn Iron Works encounter while creating these welds. They weld mostly structural steel grades, with the majority being A36, A572 Grade 50, A500 and A709 steel, including weathering types. Thicknesses range from ¼ in to 2½ in.
On deep and tight joints, reaching the root of the joint for the initial root pass requires not only the right type of MIG gun and nozzle, but also welder dexterity. With the company’s previous consumables, welding operators often had to extend their electrode stickout as far as 2 in to access the joints, a practice that risked generating porosity since it could compromise the necessary shielding gas coverage.
Another challenge the company faced was the occurrence of burnbacks, the formation of a weld inside the contact tip, when using their old brand of contact tips. Brooklyn Iron Works welding personnel run their weld beads at high amperages (300 amps to 400 amps) using typically .052 in or 1/16 in FCAW wire diameters, which often proved too harsh on their previous contact tips. They would loosen after routine welding, causing the wires to arc back and create the burnback.
The trial of Centerfire consumables gave Zammit and his team of welding operators a solution to these two problems — and it led to a MIG gun conversion that provided some additional benefits, too.
THE FIRST SOLUTION
When McGrath initiated the trial of the new consumables at Brooklyn Iron Works, he started by installing them on just two MIG guns, using a conversion adapter offered by Bernard. Zammit and his welding operators quickly realized that the design of these consumables provided a better solution for their welding operation.
The Centerfire nozzles they trialed (and now use) feature a tapered design that stays fixed flush with the end of the contact tip and allows welding operators to reach into the deep weld joints without having to extend their welding wire as much. As a result, the welding operators can gain better gas coverage and lessen the risk of porosity. These new consumables also include a built-in spatter shield that acts as an additional gas diffuser and ensures a more consistent gas flow, a feature that Zammit particularly likes.
“These consumables direct the gas exactly where we need it,” he explains. “It keeps our gas shielding coverage right at the weld, even when the doors are open or we have a breeze. We’ve never had a huge problem with porosity, but now we have even less of one.”
Just as importantly, Zammit and his welding operators have almost completely resolved their issue with burnbacks. Compared to the company’s previous contact tips, which threaded into the diffuser and tended to loosen after welding, the new contact tips “drop in” the diffuser and are held in place by tightening the nozzle. This non-threaded tip design features a tapered base and large diameter seat that helps generate consistent electrical conductivity and heat transfer — and it stays in place during welding.
“We rarely get burnbacks anymore with the Bernard contact tips,” Zammit states. “Before we had a substantial amount of downtime. And that’s money. It’s lost arc time for tip maintenance.” On the few occasions when a burnback does occur, Zammit notes that these contact tips can be easily removed — without tools — and changed because of the threadless design. He also goes on to explain that the company is saving money by having to replace fewer contact tips. By his calculation, Brooklyn Iron Works now uses about a third fewer contact tips than before.
FINDING ADDITIONAL BENEFITS WITH NEW MIG GUNS
Shortly after converting their front-end consumables, Zammit and his welding operators also decided to convert to Bernard MIG guns. They now use 400 amp, air-cooled Q-Gun MIG guns with 15 ft cables and have, since the conversion, found additional ways to reduce downtime.
According to Zammit and maintenance supervisor John Dahl, the maintenance on their new MIG guns is much simpler than with the competitive guns they used previously. Changing the neck or liner on those guns required an Allen wrench to remove setscrews on the front and backend of the MIG guns, a process that Dahl says required disassembling the MIG gun and could take nearly an hour to complete.
To change the necks on the Q-Gun MIG guns Dahl simply unscrews a plastic ring surrounding the neck by hand and inserts the new neck or liner. It takes less than five minutes. And he finds that he doesn’t have to conduct maintenance as often, either. In fact, he said that one of the new Q-Guns has been used with the same liner for a year. “Maintenance on these guns is so much easier and quicker now,” says Dahl. “Plus, we’ve gotten good feedback from the welding operators in terms of the neck options on these new MIG guns.”
The new MIG guns have necks available in fixed, rotatable and flexible options in various lengths and bend angles, with the rotatable versions being able to changeover without tools. According to Zammit, these neck options help the welding operators better accommodate the varying welding angles they encounter on projects. They can reach the weld joints easier and reduce downtime to address issues like wrist fatigue. Welding operator Ricky Curtis agrees — especially when it comes to using the flexible neck versions of the Q-Gun.
“I can bend the neck in any direction I need,” he explains. “Even around the corners. I like that the gun does the work for me, instead of my wrist.” Zammit and Allen also like that the welding operators are more comfortable and that it is taking less time to maintain the guns. Simply put, more arc-on time means better productivity.
REAPING THE BENEFITS
Keeping an open mind isn’t always easy. It’s often human nature to stay with the routine of “doing things as they’ve always been done.” But sometimes, taking a chance can yield unexpected benefits. Brooklyn Iron Works clearly learned this lesson when they agreed to a second trial of Bernard consumables. The second time around proved to be a charm, and now they are reaping the positive results that come with it – and passing those results on to their customers.
About the Author: Mike Russell is the Western U.S. account manager for Bernard and Tregaskiss at Norco Gas & Supplies (NORCO), 6102 E. Trent Avenue, Spokane, WA 99202, 509-535-9808, www.norco-inc.com.