Application Stories

The Right Power Source and Wire Combination Put the Spotlight on Aluminum Welding at Musco Lighting

To even further enhance product longevity, Musco switched to aluminum for its enclosures on Light-Structure.What do the Georgia Dome, Charlotte Motor Speedway and the Alamo Dome have in common? In addition to hosting much-watched sporting events, they all are lit by lighting equipment from Musco Lighting, Inc., headquartered in Oskaloosa, Iowa. Not only does Musco provide lighting for permanent sport facilities that range from little league fields to professional level arenas, it also provides temporary lighting for some of the country's top events such as the Olympic Games and presidential inaugurations.

Until early 1999, all of Musco's electrical component enclosures were composed of mild steel. To even further enhance product longevity, Musco switched to aluminum for its enclosures on Light-Structure orders. These electrical enclosures house the components which regulate the amount of electricity supplied to the lighting fixtures, especially as they are turned on.

Why switch? Aluminum has a higher thermal conductivity, which means it is able to transfer heat faster than steel. This provides an even cooler environment for the components that are housed inside these electrical enclosures.

But a change to aluminum meant that the company's 36 welding operators now had to be transitioned into aluminum welding. Most of these operators were used to welding nine hours a day with mild steel and had never welded on aluminum. By nature, aluminum is much more difficult to weld than steel and more prone to burnthrough. Aluminum is soft and easily flakes apart. Feeding aluminum wire is basically like trying to feed cooked spaghetti. The specific welding procedures used are critical for success. But, the right equipment and welding wire combination helped Musco make the transition a smooth one.

According to operator comments, Lincoln's machine ran smoother, had better gun ergonomics and produced a better arc."Change is always uncomfortable at first," says Brett Baer, Welding Coordinator at Musco Lighting, Inc. "We wanted our operators to feel positive about the change right from the beginning, so we let them decide the aluminum welding equipment to be used in our shop. By working with distributors in the area, we chose the two machines we felt best suited our needs. For four weeks we tested these two units side-by-side. In the end, we took a vote and the winner hands down was the Cobramatic® wire feeder and CV-300 power source package provided by Lincoln Electric. The equipment basically sold itself."

According to operator comments, Lincoln's machine ran smoother, had better gun ergonomics and produced a better arc than the competitor. Musco purchased seven Cobramatic wire feeder/CV 300 packages to be installed in its Muscatine, Iowa manufacturing facilities. The systems were delivered in early February 1999.

The Cobramatic systems ran well from the onset, but their appeal became even better when a few months later, Musco switched from a competitor's wire to Lincoln's SuperGlaze® Aluminum MIG Wire.

"When we first purchased the Cobramatic/CV-300 systems, we were welding with a competitor's wire, but were having trouble with spatter" recalls Baer. "Without announcing a change, I switched over to the Lincoln SuperGlaze aluminum wire to see if it made a difference. Immediately the operators noticed the change; it made a brighter, cleaner looking weld. From that point on we have only used SuperGlaze."

The excellent arc characteristics of the Lincoln wire, combined with the advantages and ease of use of the Cobramatic/CV-300 unit made the Lincoln aluminum welding package complete.

Weld Quality and Ease of Use
"The machine is easy to use," explains Baer. "After two weeks, the operators were achieving the same welding productivity with aluminum as they had with steel."

Once the machine is set-up, the operators don't have to worry about fine tuning the settings."One of the best features on the Lincoln machine is the ergonomics of the gun," says Carol Ebeling, Manufacturing Engineer at Musco Lighting, Inc. "The angled gun gets into the tight places such as the inside of our small 14" x 18" enclosures. The competitor's trigger gun was bulky, but welding 9 hours each day with Lincoln's lighter gun definitely helps fatigue."

According to Ebeling, the push-pull system also really impressed them. "Since the start- up with the Lincoln system, we did not experience any of the typical problems associated with aluminum welding such as tangling and burnthrough. And, once the machine is set-up, the operators don't have to worry about fine tuning the settings -- they can just weld."

"At first I was concerned about welding aluminum," states Austin Schmidt, a welder at Musco Lighting, Inc. "But after we worked with the Cobramatic the transition was smooth and I felt comfortable. Our Lincoln representative, Jeff Hughes, was on-site to provide on-the-job training and to work with us to try different gases and wires to achieve the best combination. With the Cobramatic, we are able to make consistent welds and the gun is great."

The Cobramatic is run by two wire feed motors -- a low-torque motor in the cabinet pushes the wire to keep it from dragging in the silky smooth liner while another high-torque motor in the torch controls the wire feed. In addition, the wire feeder features a proprietary brake system and grooved drive roll components to keep the wire from becoming deformed or contaminated.

Welding is generally performed at the plant five days a week, two shifts per day. The electrical enclosures are completed primarily with fillet welds on 5052 aluminum alloy that is 0.080" to 3/16" in thickness. The shielding gas is pure argon. The wire that Musco uses is Lincoln's .030" diameter SuperGlaze aluminum wire supplied in 16 lb. spools which attach right to the Cobramatic wire feeder.

"SuperGlaze seems to have better arc initiation and melts quicker during startup," reports Baer. "Our former wire seemed to hesitate and cause spatter."

"The arc is much brighter with the SuperGlaze and we are experiencing many positive starts," says Todd Hansen, a welder at Musco Lighting, Inc. "The feedability is very consistent."

Mild Steel Welding
After having such successes with the Lincoln SuperGlaze wire for aluminum welding, Musco also decided to try Lincoln's new SuperArc® L-50™ copper coated steel wire for its mild steel line.

Musco also decided to try Lincoln's new SuperArc L-50 copper coated steel wire for its mild steel line."Over the past few months, I rejected four or five skids of the competitor's steel wire because the copper coating was flaking off and the welders were complaining of erratic arc action and burned tips," recalls Baer. "With the SuperArc wire, we see less spatter, a better arc, improved feedability and instead of going through eight to ten tips per shift, we are only using one. The consumable life with the SuperArc is tremendous."

Musco has even changed to the SuperArc wire for its pulsed welding, which further cut down on spatter and offered improved feedability. Musco purchases this wire in both .035" and .045" diameters in 44 lb. spools.

"My welders love it, I haven't had a single complaint," states Baer. "Switching to the new Lincoln wire in the mild steel line is one of the best moves we ever made.

Musco has completely converted one of its electrical enclosure lines to aluminum and plans to do the same with the other by the end of the year.

"We feel we are providing a superior, more dependable product to our customers," says Doug Yates, Vice President of Sports Operations at Musco Lighting, Inc. "The investment we have made in these new aluminum machines will produce long-term savings in warranty costs."

"Overall we are very impressed with the service provided by Lincoln and the quality of their equipment and wire," says Baer. "When we installed the new equipment, the Lincoln representative was coming in three times a week to check things out and bounce ideas off of him. Even now that we are up and running with the new systems, he still stops by -- not to sell us more equipment, but to make sure we are happy with the equipment that we already have"

"From what we have experienced during this switch to aluminum, we would certainly evaluate any Lincoln systems for future growth opportunities," comments Yates.