Anatomy of a Construction Site: The Welding Equipment, Filler Metals and Protective Solutions Working on the Lambeau Field Expansion

Miller Electric Mfg. LLC and Hobart Brothers have been named as the Official Welding Equipment Provider for the Lambeau Field Expansion by the Green Bay Packers. Through a partnership with Miron Construction Co., Inc. — the Official Provider of Construction Services for the Green Bay Packers and Lambeau Field — Miller and Hobart Brothers have worked to bring the latest in welding technology to the site. In this brief article we’ll review the technologies used on this project and cover some of the specific facts about each that are pertinent to this project and the construction industry in general. 

Engine-driven Welders

One of the most common pieces of equipment found on any construction site, the engine-driven welder is equally adept at structural steel erection, mobile fabrication, and maintenance and repair work. These tools are particularly helpful because they offer both welding and power generation capabilities for running construction jobsite tools in a single package. In the context of the Lambeau Field expansion, operators used engine-driven welders primarily in the reinforcement of steel columns to support the new structure and to run jobsite tools. Welders here relied on a number of Trailblazer® Series welders including the Trailblazer 325 EFI with Excel™ power. Key benefits to the Trailblazer 325 EFI include:

• Up to 50 percent longer runtimes compared to previous models and comparable machines. They require less downtime associated with refueling and ensuring more productive time.
• Up to 35 percent reduction in fuel use for significant cost savings.
• Sound reduced by as much as 68 percent for a safer, more productive jobsite.
• Up to 5 inches shorter and 108 pounds lighter for greater mobility and space savings.
• Smart-Cor™ technology provides independent welder and generator power for no interaction between jobsite tools and the welding arc for optimal welding arc quality.
• Excel power provides 120 volts/60 hertz of pure sine wave auxiliary power at all speeds to run most jobsite tools at idle speed.
• Electronic Fuel Injection (EFI) substantially reduces fuel use, offers fast and easy starts in all climates, requires no choke and is less prone to fuel deterioration.
• Auto-Speed™ technology adjusts machine output to match the job at hand, ensuring optimal fuel use and operation. 
• 325 amps of welding power in all processes at 100 percent duty cycle. It also features 12,000 watts peak/10,500 watts continuous auxiliary power plus 2,400 watts of recommended/optional Excel power. 

Dual-operator engine-driven welders

Miron used two dual-operator engine-driven welderson the Lambeau Field expansion: The Big Blue® 450 Duo CST™ and the Big Blue 700 Duo Pro. Dual-operator systems allow for two operators to weld off of the same machine with no interaction between the two welding arcs, and also provide industrial-strength auxiliary power for running jobsite tools. The benefits of running dual-operator systems include improved productivity and a lower total cost of ownership than two separate machines. These systems also mean less equipment to transport to each site and reduce noise and emissions compared to two machines.

The Big Blue 450 Duo CST features two CST 280 Stick/TIG inverters and 12,000 watts of continuous three-phase power. The machine offers superior performance on difficult stick electrodes found in structural steel and fabrication applications, such as E6010. It also provides excellent TIG performance for pipe fabrication and maintenance applications. It operates at a low 1,800 RPM, which reduces fuel use. This RPM also keeps noise levels up to 10 dBa quieter than other models, improving work site communication and safety.

The Big Blue 700 Duo Pro offers two independent welding arcs up to 400 amps (no interaction between the arcs), and the ability to parallel both independent welding outputs to create an extremely powerful 800 amps of welding power for running large electrodes, stud welding and carbon arc gouging (up to 3/8-inch carbons). Offering full multiprocess capabilities, the Big Blue 700 Duo Pro also offers two independent auxiliary outputs. One 5,500-watt-peak/4,000-watt-continuous single-phase auxiliary output is fully independent of weld output and offers peak performance even when welding at 700 amps (no interaction between arc and output power). The second auxiliary output (27,000 watts peak/20,000 watts continuous) provides more robust power for high power needs on site.

Welding power sources for construction

For a site like the Lambeau Field expansion, where there is existing power within the structure, Miron uses inverter-based power sources such as the CST™ 280 Stick/TIG welder and the XMT® Series of multiprocess power sources extensively. These small and compact welding units allow for excellent portability and accessibility on larger construction jobsites and are extremely energy efficient. Stick welders like the CST 280 are common fixtures on aerial lifts for welding in high places. And the XMT Series inverters are commonly matched with a SuitCase® X-TREME™ 12VS wire feeder for self-shielded flux-cored welding. Key features of each machine:

• The CST 280 offers 280 amps of output, which is ideal for Stick electrodes up to 3/16 inch. This power source is extremely easy to operate with a process selector knob that automatically sets the proper dig setting on E6010 and E7018 electrodes for optimal performance. At 41 pounds, these units are portable and are often found in racks of four, which allows easy transportation around the site and multiple arcs to run from a single location.
• XMT Series power sources provide excellent multiprocess capabilities in a single compact unit. Miron used the XMT 304 extensively for both stick and flux-cored welding. It offers a rated 300 amps of welding power at 60 percent duty cycle.

SuitCase wire feeders

Built to be durable and face the rigors of welding on a construction site, the extremely portable SuitCase X-TREME 12VS voltage-sensing wire feeders also offer excellent arc starts and improved arc performance for all types and sizes of wires. As the wire feeder runs off of open circuit voltage, it does not require an extra control cable —eliminating clutter and hassle. The feeder also offers a trigger hold function that improves operator comfort on long, continuous welds. The potted and trayed main circuit board helps protect the machine and ensures excellent reliability in the harshest of environments.

Induction heating

Welders used the ProHeat™ 35 induction heating system from Miller throughout the project as a faster and more efficient way of bringing steel columns to temperature – and keeping them there – than using traditional heating methods such as a propane-fueled torch. Preheating helps prevent rapid cooling of the weld metal, relieves stresses and drives out hydrogen that can lead to cracking and embrittlement. The system creates heat electromagnetically in the material with induction heating rather than by surface heating, as with an open flame. The induction cables do not heat up themselves, but create eddy currents that generate heat throughout the plate and column. Overall benefits of the process compared to heating with a torch are:

• Faster time-to-temperature
• Consistent heating throughout the entire part
• Easier to apply/wrap heat
• Lower consumable costs by reducing/eliminating gas expenses
• Reduces total weld cycle times – improving productivity
• Improved safety for employees (no open flames or hot heating elements)

Portable welding fume extraction equipment

Miron also used the FILTAIR® 130 portable fume extractor extensively in the indoor areas of the stadium, including hallways, press rooms and locker rooms. Fume extraction in this application helped in two key ways. It helped keep the area cleaner by removing airborne particulate at the source of the weld. The extractor also improved the environment for the welder, making it easier to see and breathe in confined work environments. The FILTAIR 130 features FilTek™ XL Filter Technology specifically designed for capturing welding fumes. It boasts a MERV 16 rating, making it the class leader in filtering out submicron particles found in weld fume. A manually cleanable filter makes it easy to clean and extends filter life compared to other solutions on the market. Plus, this unit is extremely portable at 46 pounds.

Welding filler metals – stick and flux cored

Welding operators used two primary filler metals on the Lambeau Field Expansion: The Hobart® 418 (E7018-1 H4R) Stick electrode and the Fabshield® XLR-8™ (E71T-8JD H8) self-shielded flux-cored wire. The Hobart 418 Stick electrode is a good general-purpose low hydrogen electrode for use in all welding positions. It offers excellent arc stability, low spatter levels and easy slag removal.

As work on the site transitioned to flux cored welding, welders switched to the Fabshield XLR-8 wire. This wire requires no shielding gas and is perfect for welding outdoors in construction applications. This particular wire provides a low hydrogen weld deposit and high impact strength properties at low temperatures to resist cracking. It also offers excellent out-of-position performance even at high current levels and excellent mechanical properties under a range of heat inputs. Fabshield XLR-8 wire also delivers good slag removal for increased productivity and reduced slag entrapment.

PPE for welding in construction

Safety is paramount to welding applications on construction sites. Welders were outfitted with Arc Armor™ welding protective equipment to provide the right mix of comfort and protection. Featured solutions on the Lambeau expansion site included:

• Heavy-duty MIG/Stick gloves: built from durable side-split cowhide, these gloves provide excellent protection and are designed for extended wear. Aluminized insulation reflects radiant heat, and the pre-curved pattern is designed to fit the natural shape of the welder’s hand for optimal dexterity and comfort.
• Classic cloth flame-resistant jackets: provides comfortable wear with a barracuda-style stand-up collar for extra neck protection. Extremely durable with finished hems and reinforced stitching, these jackets are ideal for a wide variety of applications.
• Pro-Hobby™ Series auto-darkening welding helmets: a 6.06 square-inch viewing area with an auto-darkening lens provides excellent visibility and protection for the welder.