Slow welding makes fast cars for Team RahalSlow welding makes fast cars for Team Rahal

When welding together thin sheets of titanium for Team Rahal racing cars, Dan Dreisbach is very particular about his welding equipment. "If the welding arc starts off too abruptly, it's easy to burn a hole right through the poster-board thin titanium sheets."

The issue is the machine's high-frequency starts, Dreisbach explains. "The welder I was using previously had a problem with violent dc starts that were causing my tungsten to become contaminated," he says. "This, in turn, created poor-quality welds that needed extra grinding time."

Team Rahal pushes the capabilities of welded parts such as radiators, suspension components, exhaust systems, gearbox cases, accelerators, and brake pedals, so there is always a possibility that a faulty weld on titanium or other metals could end the race for the Rahal Team.

"Titanium is used for the vehicle's heat shields and brackets be-cause it is extremely flexible and lightweight," says Dreisbach. "Nickel-based material is nearly indestructible and able to withstand heat at minimum thickness, so we are now using this metal for exhaust systems."

With the Micro-Start system on the 275 and 375 welding equipment from Lincoln Electric (Cleveland, OH), violent dc starts have been completely eliminated, according to Dreisbach. "The MicroStart provides better control of the high-frequency starts than any other welder I've used," he says. "The difference is similar to using a dimmer switch instead of a toggle switch to turn on a light."

Product Manager Jim Harris, an electrical engineer at Lincoln Electric, says that the patent-pending MicroStart system has an independent electronic welding power supply. "It uses a separate circuit that augments the main power supply and provides a low, 2A output, which is especially important when starting the welding machine and creating an initial arc."

The MicroStart minimum output control also lets Dreisbach adjust the starting current output for different sheet-metal thicknesses. Team Rahal's shop welds thin, 0.016-inch sheets of materials, as well as thicker castings. The welding operations include many material types, such as 4130 steel, stainless steel, aluminum, titanium, brass, and copper.

"Lincoln's advanced equipment helps us create superior welds on these newer materials and realize our overall goal to achieve lighter-weight vehicles," says Dreisbach. Dreisbach also mentioned that Team Rahal fabricator also liked the dimensions of the new welder. It's depth of 36 inches from front to back fits on the benches the team uses for welding. The height of the welder, approximately 3 feet, puts the control unit at a natural hand level and leaves room underneath for storage. The welding machine's cables and connection are covered by an access door. The machine also holds two different types of common electrodes and has a cooling fan horizontally mounted on top. Instead of using plastic threads for connections with torches and solenoids, the Lincoln Electric Welding machine uses brass threads. Dreisbach adds that the brass threads are more durable and less likely to strip than plastic threads.

The innovations that come out of Team Rahal's experience are also beneficial in aerospace and other applications where thin, sheet-metal welds are important.

For more information about welding equipment from Lincoln Electric Co., www.lincolnelectric.com: Enter 538