The right welder for structural steel
Coastal Steel, Inc. is a full-service steel erection company based out of Tacoma, Wash. The company specializes in commercial steel structures up to four stories, ranging from big box retailers to churches and municipal buildings. One recent project was a new addition to a Catholic school in a residential area in suburban Seattle. The two-story building featured approximately 25,000 square feet of floor space, 200,000 pounds of structural steel and 30,000 pounds of decking.
For a contractor like Coastal Steel, one of the most important tools is the welder/generator. Having the ability to weld and run tools off of one centralized engine-driven unit helps reduce the amount of equipment needed on site. The company has spent the last year putting the new Trailblazer® 325 EFI with Excel™ power to work as a welding power source and as a primary generator. Through new advanced engine technologies designed for both performance and quality, Coastal Steel has experienced savings in fuel and reduced noise output—helping to reduce the bottom line and improve sound quality on site for workers and neighbors.
The importance of the welder/generator in structural steel erection
At its most basic level, structural steel is erected using a combination of welding and high-strength tension shear bolts, or TC bolts—both applications powered by an engine-driven welder/generator. The new Trailblazer 325 EFI offers 325 amps of welding power at 100 percent duty cycle, 12,000 watts of generator power and an additional 2,400 watts of optional Excel power.
Welding requirements in this application vary based on the process and type of joint being welded. Welding with the Flux-Cored process typically requires between 225 and 280 amps when welding with a .072-inch diameter flux-cored wire. For Stick welding, the machine typically resides between 135 and 170 amps for 5/32-inc. electrodes and 110-130 amps if using a 1/8-inch electrode. The 325-amp/100 percent duty cycle performance of the machine allows Coastal Steel to run all of these processes without worrying about exceeding the duty cycle.
To apply the high-strength tension shear bolts, Coastal uses a “Lejuene Gun”, an electric shear wrench, off of the machine’s generator power. This tool requires 1,400 watts of power — easily handled by the primary generator power or the optional Excel power. Most other typical jobsite tools (lights, grinders, drills, screw guns, rotor hammers) require less power. While the Trailblazer 325 EFI is designed to run seamlessly with suitcase-style wire feeders, Coastal Steel has even used the machine’s generator power to run two separate 110-amp MIG welding units, turning it into a three-arc welding system.
“On this machine here, I’ve run two Millermatics off the generator side of it, and SMAW off the welder side of it,” says Hummel. “The generator source is very good on this machine. If you don’t have the right power on the job site, it’s right there for you.”
Keeping welding and generator power separate ensures proper performance
As power tools are often being run at the same time as the welding arc, it is important that there be no deterioration or interruption of the arc itself. Some traditional engine-driven welder/generators will experience a fluctuation in the arc when a load is applied to the generator. This fluctuation can lead to defects in the weld.
“When you’re doing a full penetration weld, when your volts are high and your amperage is high, if you draw down a small bit, it can cause pinholes, it can cause cold roll,” says Hummel. “There’s only a fine line with Flux Cored when you’re running those full penetration welds. You’re as hot as you want to be and you don’t want it to change.”
The new Trailblazer 325 EFI features Smart-Cor™ technology that allows for the weld and generator power to remain entirely separate. This ensures no interaction between jobsite tools and provides stronger, cleaner, more efficient generator power.
“The generator and the welding side are independent,” says Hummel. “So they’re running a lot of power off it and you’re welding off it at the same time, and you don’t get any drawdown on your welder—you can’t tell that you’re running power. Other machines you don’t have that, especially on the FCAW side of it.”
Exclusive engine technologies provide new levels of efficiency
There are two primary factors that allow for the reduction in fuel use and sound on the jobsite: Auto-Speed™ Technology and Excel Power. (A third technology, electronic fuel injection, further contributes to fuel savings). Auto-Speed technology is a new feature for engine-driven welder generators that automatically adjusts the engine to run at lower speeds depending on the total power needed. Traditional engine-driven welder generators will run at a full 3,600 RPM for all applications. With this new technology, engine speed briefly jumps up to 3,600 RPM and then automatically lowers to match the task at hand. Certain loads, such as running 1/8-inch electrodes at relatively low amperage rates, allow for the machine to carry the function out at idle (2,400 RPM).
“If you’re running an 1/8-inch 7018 electrode, it will only idle up small amounts at a time,” says Hummel. “It’ll just give you enough RPM to run at 125 amps. If you’re running flux-cored wire, it will idle up more to run 20 volts. It will do what it has to do without doing too much.”
The second technology, Excel power, is similar in that it allows jobsite tools to run at 2,400 RPM. In traditional welder/generators, the machine immediately ramps up to 3,600 RPM when a generator load is applied. With Excel power, which is a separate from the machine’s main generator and offers an additional 2,400 watts of generator power, the machine runs most common worksite tools — grinders, chop saws, drills and lights — at idle speed.
“I like that it’s quiet and I like the fuel savings,” says Hummel. “It’s better on gas than other machines.”
Fuel savings add up with electronic fuel injection, lower RPM
For companies like Coastal Steel, fuel use is a major factor when selecting equipment. Another key factor contributing to reduced fuel use is electronic fuel injection. Electronic fuel injection optimizes air/fuel ratios for all engine speeds and loads, ensuring operation at peak fuel efficiency. It also helps eliminate the starting problems encountered with carbureted models in colder/Northern climates. As fuel prices continue to rise, every bit of fuel savings helps. With this and the other technologies found in this machine, contractors will notice up to a 35-percent drop in actual fuel use, and runtimes on a standard 12-gallon tank extended by as much as 50 percent. Over the course of the year under typical use1, those fuel savings could be as much as $1,600.
“I can run this machine about 20 hours on one tank of gas,” says Hummel. “I believe it’s about 30 to 40 percent better on gas than other machines. You might get 12 hours out of (other machines), but they either run on low idle or high idle—it’s all the way or nothing.”
Compared to older machines, that extended runtime is significant. It allows welders to go longer between fill-ups, minimizing non-productive activities such as refueling or driving to get fuel.
“You might get 12 hours out of (other machines) depending on how hard you run them,” says Hummel.
The reduction in hard costs is evident.
“You have to save every little chance you can save. If you’re saving $20 a day (across a fleet), that’s $100 a week. That’s the bottom line.”
Reduction in sound improves work environment for neighbors, workers
In the case of this specific jobsite, where Coastal Steel built an addition to a structure surrounded by a residential neighborhood and a school, the ability to operate at lower sound levels is beneficial to both the neighbors and workers on the site. Steel work begins at 7 AM, and school starts at 7:30 AM. Due to the ability to run most processes at lower RPM and an improved packaging design that helps the engine run cooler and produce less noise, the Trailblazer 325 EFI produces up to 68 percent less sound compared to previous models. This makes the work less intrusive to the surrounding neighbors, as well as the students in the school.
“There are houses 100 yards away,” says Hummel, “and we can’t start until 7:00 because of the houses. The noise reduction is good anywhere, even for my sake, because I’m tired of hearing (welder/generators) wide open all day long.”
Also important, the reduction in sound helps improve jobsite communication and ultimately makes it a safer place to work. Taking all efficiencies into consideration, Hummel sees it as a good fit for structural steel erection.
“When it’s on low idle, you can talk around it and you can hear yourself,” says Hummel. “It’s definitely a quieter machine than any other machine, the fuel savings is good, and having the separate generator and welding power is a big deal.”
1Estimated based on typical usage – 150 amps welding 40 percent of the time; 20 amps generator power 30 percent of the time, and idling without load 30 percent of the time.