If you had 90 MIG welding stations, how many MIG guns would you actually own? Many companies would provide a number greater than 90. Be honest: how many extra guns are in your tool crib? The best answer is “as few extra as possible.”

Many companies anticipate breakdowns by purchasing additional backup equipment. However, planning for a failure is less productive than preventing the failure in the first place. For example, when a gun fails, how long does it take for the welder to notify maintenance and for maintenance to respond, or how long does it take the welder to walk to the tool crib, obtain another gun and swap out the old gun for the new? In a large production facility it takes, at best, 15 minutes, but more likely up to an hour. How much do you value those 15 to 60 minutes?

At Ridg-U-Rak, a pallet storage rack manufacturer in North East, Penn., 15 minutes to their welders can have a direct effect on their piece part output. Ridg-U-Rak has tackled its maintenance problems head on in order to maximize its welders’ productivity and address MIG welding downtime, including:

• Wire kinking within the power cable where it connects to the wire feeder.

• Birdnesting and buckling of the wire within the gun liner or at the drive rolls.

• Premature liner wear, inconsistent feeding and erratic arc performance due to weak strain reliefs. (A weak strain relief causes the gun cable to droop at a sharp angle as it comes off the wire feeder).

• Loose power cable and wire feeder connections from low quality power pins that that cause higher electrical resistance, overheating, gas leakage and erratic arcs.

“Ridg-U-Rak welders are getting paid to weld as many parts as possible.” says Ken Dougan, branch manager, General Welding. “Anything we can do to eliminate common sources of wirefeeding downtime helps a welder take home more money and increase material throughput of the plant.” Ken Dougan has personally been serving Ridg-U-Rak’s welding supply and service needs for more than 20 years.

One of the largest manufacturers of pallet racks in the United States, Ridg-U-Rak has two production facilities in North East, PA that have a combined annual production capacity in excess of 100 million pounds of product (see photo 1).

Photo 1: Eliminating the sources of maintenance problems upfront allows Ridg-U-Rak’s welding operators to produce over 100 million pounds of pallet racks annually.

To meet Ridg-U-Rak’s high quality standards, operators produce full penetration welds on every component to ensure maximum strength, whether they are welding in flat, horizontal or overhead positions. Depending on the component operators can produce up to 30 welds per piece (see photo 2).

Ridg-U-Rak uses 20 inverter-based CC/CV power sources (Miller XMT® 304s with a 300-amp output at 60 percent duty cycle) and 70 three-phased CC/CV DC power sources (a combination of Miller Dimension™ 450, 451 and 452 welding power sources). For positive wire feeding performance, the company pairs these inverters with Miller four drive roll wire feeders of various vintages. Ridg-U-Rak uses ER70S-6, 0.35-inch steel filler wire and the company’s previous MIG guns were 300 amp air-cooled MIG guns (see photo 3) with 15-foot power cables.

A customer solution oriented company, Ridg-U-Rak uses both direct shipment and stocking distributors that maintain inventories of the most commonly used rack components for efficient product delivery. Full-time Ridg-U-Rak installation crews ensure quick rack set-ups in both new warehouses and existing storage facilities.

According to Dougan, Ridg-U-Rak always provided him with excellent feedback about welding equipment performance. During one of Dougan’s routine courtesy visits, he spoke with maintenance supervisor Tom Landhl and repair technician John Ramsdell at Ridg-U-Rak about MIG gun maintenance.

Ridg-U-Rak welders relied heavily on the maintenance department to support its welding operation. If a gun misfed, needed a new trigger, liner or power cable assembly, the welder would call the maintenance department.

“John is actually the guy who has to fix the MIG guns and his job is to keep the operators welding with as little downtime as possible,” says Dougan. “He wanted a gun that was more durable, had a better strain relief and would hold up better, so the operators would spend less time contacting him for issues such as wire misfeeds.”

Photo 2: Some Rid-U-Rak components require 30 or more welds, and since welding operators are paid per piece, they need MIG guns that provide consistent wire feeding performance.

As a result, Dougan proposed implementing a trial period of Bernard Q200 and Q300 MIG guns with 15-foot power cables with a blend of Argon and CO2 shielding gas.

Since Dougan has been selling welding equipment and supplies for more than two decades, he’s learned a lot not only about problem solving, but also problem prevention. Keeping in mind that most MIG gun downtime is caused by loose power pin and wire feeder connections, weak or non-existent strain reliefs and premature liner wear, he believed that the Q-Gun would prevent these problems from occurring.

Tighten Up

“The power pin—the component that connects the gun and power cable to the wire feeder—has a major impact on wire feed capability,” says Emil Vasek, MIG Specialist, Bernard. All MIG guns work great out of the box but in as little as a month’s worth of moderate use, components loosen up and deviate from factory specs.

Photo 3: To reduce maintenance downtime caused by wire misfeeds, Ridg-U-Rak equips its 90 MIG welding stations with 200 and 300 amp Bernard® Q™-Guns with 15 ft. power cables.

A low quality power pin loses its ability to maintain a tight connection over a shorter period of time. As a result, the wire can become tangled within the weak point at the resulting gap, which causes kinking at the drive rolls within the wire feeder. A loose connection can also cause gas leakage and poor electrical conductivity that could lead to erratic arcs and poor weld quality.

At Ridg-U-Rak, the previous guns used a power pin adapter link that did not provide a strong connection between the wire feeder and power cable.

“The power pin adaptor is the weak link in the wire feeding system,” says Dougan. “What happens is that the adapter breaks or causes a birdsnest within the wire feeder.” The Bernard® Q™ -Gun preempts this problem because it uses a heavy, sturdy power pin that seals the connection tightly. The Q-Gun’s power pin bushings and direct plug technology help minimize gaps within the MIG gun and wire feeder interface (see photo 4).

Strain Relief Lowers Cable Stress

Another major cause of wire misfeeds are weak or nonexistent strain reliefs on the back end of the gun. In fact, Ridg-U-Rak maintanence technician John Ramsdell, originally asked Dougan for a gun with a better strain relief to eliminate birdsnesting and misfeed problems.

A gun with a rigid strain relief at the connection between the power cable and wire feeder prevents the power cable from kinking. A kinked power cable is somewhat equivalent to a kinked water hose: the water pressure would be weak or may not even exit the nozzle, and the hose would wear prematurely at the kinked point. The strain relief keeps the power cable as straight as possible so the wire and shielding gas can flow freely, and it eliminates the potential for excess liner wear at the bend point.

“The Bernard Q-Gun features the industry’s most durable strain relief,” says Dougan. “At Ridg-U-Rak, the Q-Gun’s strain relief prevented the power cable from bending, which eliminated the root cause of many wire feed problems.”

A Smoother Design

Liners are another critical component of a MIG gun. In fact, “Many feeding problems originate with the liner and its replacement can be among chief causes of downtime and maintenance issues,” says Vasek. “During manufacturing, Bernard’s liners undergo a proprietary in-house coiling process which helps achieve optimum wire feed performance.”

To keep liners free of debris and obstructions and extend liner life, welders blow out liners with compressed air between wire changes. This only takes a few seconds, yet can save Ridg-U-Rak’s welders from spending 15 minutes or more walking to the tool crib and back to replace a worn liner.

Less is More

“While preventive maintenance remains an important activity, I believe that the Q-Gun can help eliminate many of Ridg-U-Rak’s emergency maintenance issues,” says Dougan.

“After 4 months of service, the gun front end has held up longer and the cable has not pulled out of the feeder,” says Ramsdell. That means that Ridg-U-Rak operators spend more time welding and less time waiting for a MIG gun to be fixed by maintenance.

Accepting equipment failure is a guaranteed method of killing productivity. Instead, tackling the root cause of equipment maintenance problems, like Ridg-U-Rak has done, can improve productivity drastically. By initiating a trial period of the Bernard Q200 and Q300 MIG guns in select welding cells, Ridg-U-Rak has been able to compare the difference in maintenance time to their previous MIG guns and they are satisfied with the reduced downtime.

“Our operators demand a lot from our MIG guns. They’re used on two different shifts by two different operators,” adds Landhl. “Bernard has made great strides in the durability of these MIG gun parts. As a result, I spend less time on maintenance and the operators spend more time welding.”

For further improvements, Ridg-U-Rak plans to standardize on one or two models of MIG guns, purchasing them the as its old guns wear out (the life expectancy of a gun in a high production facility running three shifts is 6 to 18 months). Reducing the number of MIG gun models will also help Ridg-U-Rak reduce costs associated with tracking, ordering and inventorying parts.

Ridg-U-Rak welders appreciate less maintenance. Since they’re paid on a per part basis, they prefer to spend time welding, not talking to maintenance personnel about equipment failures.