Edited by Kimberley Gilles, associate editor

A Greenheck welder uses a Millermatic 350P to lay welds on an aluminum louver.

Photo courtesy of Greenheck Fan Co.

A sampling of Greenheck's aluminum louver line.

Greenheck Fan Corp. (www.greenheck.com), a manufacturer of air movement and control equipment, has been growing for more than 60 years. Bernie and Bob Greenheck started their business as a two-man sheet metal shop and developed it into a company with 2,000 employees, including 180 welding operators. The company's latest growth spurt involved adding welders — both men and machines — to fabricate enough aluminum air louvers to meet rising demand. The louvers are the type that allow air to pass between the inside and outside of a building.

Managing the first part of the expansion plan — adding men who can weld — was not a problem for Greenheck: The company trains its own welders.

"We had a hard time finding welders," says Josh Holtz, senior manufacturing engineer. "We wanted a way to make more welders when we needed them, so we started our own internal training program. We either hire people who will be good employees for us, or take some of our existing good employees who are interested in becoming welders, and we train them to weld," says Holtz. Every welder must go through the company's training program, regardless of their experience in welding.

The second part of the expansion plan — buying welding machines to increase capacity — required Holtz to evaluate the available options.

"As a rule, when purchasing welding equipment, we look at three main factors: performance, cost and reliability" notes Holtz. "In this case, we were looking for a welding system that welds thin aluminum effectively, yields welds that are cosmetically appealing, and is dependant and versatile." The company eventually chose to purchase 12 Millermatic 350P pulse MIG welders from Miller Electric Mfg. Co. (www.millerwelds.com)

Welding louvers
Greenheck's architectural louvers are made from aluminum alloys 5052 (magnesium alloy) and 6063 (magnesium-silicon alloy) that range in thickness from 0.08 in. to 0.75 in. All the welded joints — T, edge, butt and lap — must be strong and cosmetically appealing because the louvers are functional and provide an architectural detail.

Aluminum presents unique welding challenges. It conducts heat about six times faster than steel, so higher amperages and faster wire feed speeds are required. Aluminum also has a melting point (1,220 degrees F) that is low relative to the melting point of other metals. Both these factors combine to make the metal susceptible to burn-through, especially on thinner material.

"Our experience with our older-technology welders told us that they're geared to run thicker material," says Holtz. Greenheck was using inverter-based welding machines with pulsed MIG capabilities before it purchased the Millermatics.

"The (older machines) weld very well on thicker aluminum, ranging from ³ /16-in. to ¹ /4-in.," says Holtz. "But we always had problems once we got to the 0.10-in. and thinner stock. Most of the welds on the louver line needed to be just ¹ /8-in. wide." That was tough to achieve with the older machines, so the welders created ³ /16-in. fillets. Sometimes they made even larger welds because of the style of the joint and the welding position, Holtz adds. However, that wasted metal and increased the chance of burn-through and blistering.

Cost savings
Greenheck now has about 40 welding operators who work in three shifts and use the 12 new machines. The company reports that rework on the aluminum louver line dropped 10 percent and that the use of filler metal dropped 25 percent since the new machines were put into production. "We found that the 350P has a much more refined pulsed arc, and we can control the amount of penetration and weld size," says Holtz. "With the better arc control, we can keep the weld size small, and the louvers are more cosmetically appealing. Now we can hit weld size where we could not before."

A 25 percent reduction in filler metal consumption for a company that uses 1,000 pounds of 0.047-in. 4043 filler wire per month at an average cost of $3.35 per pound translates into annual savings of $837 per month or $10,044 per year, according to Miller Electric.

Training the future trainers Clay Erickson has gone through Greenheck's welding training course. Greenheck Fan Co. is not required to certify its welders or hire certified welders, but it has developed a training program that encompasses some of the training principles established by the American Welding Society. Instructors are selected from the company's workforce based in part on their dedication to the welding operation and their commitment to the company's continual improvement process, says Josh Holtz, senior manufacturing engineer. Trainees first learn about the seven welding variables — amperage, voltage, contact-tip to-work distance, travel angle, transverse angle, travel speed and wire position — and about welding procedures, base metals and joint positions. The trainees then move to the production floor, where each trainee works one-on-one with their trainer until each trainee can work to production levels without supervision — usually about two to three weeks, says Holtz. The newly trained welders, as every other welder at the company, must produce welds that meet the company's quality standards.

Challenge: Manufacturer of ventilation products needs more welders and welding equipment to boost production of aluminum air louvers. Solution: Trains employees to weld and purchases equipment to support the company's growth.