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Skyline also knew that if they were going to venture into automation, they would need assistance. After initial research into automated welding systems, Skyline turned to its Praxair representatives, Jim Kelly and Joel Ashmore, who did some research of their own. Together, the two companies came up with an automated welding system to meet the challenge. The team produced an acceptable weld in one week, while their competitor had been unable to produce an acceptable weld in nine months.

“Once we understood what the end result needed to be, we got together with our suppliers, Hobart Brothers, Bernard and Miller Electric, and we acquired the equipment and consumables to do some development work in our Phoenix laboratory,” said Kelly, who is a productivity specialist with Praxair.

“Along with that, we decided to use a proprietary gas mixture to increase deposition rates, and an automated linear travel system to achieve the continuous welds,” he added.

Praising Praxair's commitment to the project, Dancer said the jog was a bit of a gamble, but that it has turned out to be better than he expected.

The Wire

Skyline and Praxair chose 1/16-in. Tri-Mark Metalloy 76 metal-cored wire from Hobart Brothers because it produces a high-deposition, aesthetically appealing, and spatter-free weld.

“The Metalloy 76, combined with a proprietary Praxair gas blend, cut through minor mill scale, mill oil and other light surface contaminants and still produced a spatter-free, slag-free weld,” Kelly said.

Using 400-lb. drums instead of individual spools of wire reduced the overall cost and footprint of the wire, and it reduced production downtime associated with spool changeovers.

Metal-cored wire is comprised of a very thin-walled, hollow metal sheath that is filled with metal powder and deoxidizers. The current flows primarily through the outer sheath of the wire to produce a more concentrated and conical welding arc than solid wire. That, in turn, produces deeper penetration and higher deposition rates than solid wire.

Metal-cored wire usually is used at high amperages with a spray transfer process that requires shielding gas with a high argon content, typically 80 percent to 95 percent with the remainder carbon dioxide. The spray transfer process also produces smaller droplets of filler metal to create a calmer weld puddle.

The Power Source

Sometimes referred to as the tank of power sources because of its durability, the Dimension 1000 provided the welding power for the project. Skyline and Praxair chose Miller's Dimension 1000 power source for its reliability — especially at high temperatures — and its high duty cycle rating.

“We're running a high amperage project with a large diameter wire, so we needed a machine that would have the power available to run continuously at those current levels,” explained Kelly.

Another reason Skyline and Praxair chose the Miller product is that Miller rates all of its welders to 104° F, which helps to ensure that the stated current levels will be available, even in the Arizona heat.

The Dimension 1000 offers direct current constant voltage (CV) capabilities for Gas Metal Arc Welding and Flux-Cored Arc Welding as well as constant current (CC) capabilities for Shielded Metal Arc Welding and Carbon Arc Gouging. It also features Fan-on-Demand, which reduces the amount of airborne contaminants that enter the machine, and sealed circuit boards, which protect its electronic circuitry from contamination.

The Gas

To increase the deposition rates and provide a stable arc, Praxair recommended a proprietary gas blend that was developed for use in automated welding systems.

Using a standard gas mixture would have been less expensive than the Praxair blend, but looking at the full cost of the welding operation, Skyline saw that the improved deposition rates of the Praxair mixture would more than offset the cost of the gas.

The Automation

Bringing together the wire, power source, consumables and gas was the automated linear welding system that consists of a manipulator arm that travels the distance needed to allow Skyline Steel to produce a continuous weld for the entire length of the joint.

Torch-mounted feelers sense the joint and adjust the torch as needed while an operator observes through a custom welding shade. A programming pendant allows the operator to change the welding parameters remotely.

The arm also holds the power supply and the wire, making the welding connections as sound as possible to eliminate potential welding flaws caused by poor connections in the welding cables when traveling such distances.

The system was able to produce the continuous, flawless welds required by the project almost immediately.

To compare the difference between the automated system and the human element, the shop had one of its welders perform the same weld that the automated system made.

“It wasn't pretty,” Dan Henry, shop foreman for Skyline said.

“It took a long time and we still had the problem with starts and stops. This machine does the work of 10 guys, and the welds are perfect,” he added.

Moreover, the automated system far exceeded everyone's expectations by averaging a travel speed of 18-in. per min. and depositing 18 lbs. per hr. of finished weld.

“We're producing at about twice the rate that we thought we would, and that we had to to make this a profitable endeavor,” Dancer said. “And, since we're producing at twice the rate we expected, we're also profiting at twice the amount we expected.”

Part of that productivity is attributable to the perfect record in ultrasonic tests and reduced clean-up. “We test every column we manufacture and not a single one has failed ultrasonic testing,” Henry said. “Plus, there's considerably less time spent in non-value added post-weld operations, such as chipping slag or grinding spatter.”

Just as importantly, they have exceeded their client's expectations.

Douglas Gabriel of Archer Western concurred. “Going with Skyline has helped us tremendously,” Gabriel said.

Looking Forward

On its own, the success of the project made the equipment investment worthwhile, but the real payoff will come as Skyline uses the automated technologies and integrates the metal-cored wire into its other fabrication operations to win new business.

“We're now in a position to seek out new jobs that can take advantage of the capabilities of this system,” Dancer said. “It's not going to be hard to find work for this piece of equipment, especially after people understand what it's capable of doing from an ‘end result’ standpoint.”

“These guys want to work. They get frustrated when they have to go change out wire,” Henry said. “Now they don't have to change out the wire nearly as often, and with the overhead boom, there aren't any cables on the floor to roll over. We were welding like it was the 1950's. Now we're welding like it's 2009. That feels good, and it makes great business sense.”