November 7, 2006
Of all the fabrication tools necessary to build -- and repair -- race cars, welding equipment is one of the most essential. To keep a race car together, safe for drivers, and at its competitive best, welding and metallurgy come into play every day in the motorsports industry.
"Drive fast, turn left" may be a popular motto among race car drivers, but motorsports fabricators have their own: "Drive fast, weld right."
A successful racing team is the sum of its parts, from the fabricators to the painters to the drivers. One of the most critical components is welding, which helps keep drivers safe and is key to building cars that outperform the competition.
Fabricating a race car takes a lot of tools: snips, grinders, pneumatic tools, deburring knives, adhesives, abrasives, fasteners, cutting tools, CNC equipment, lasers, drill bits, shears, saws, drills, nuts, bolts, and, of course, welding equipment.
All of them help define a race car's appearance.
"It's gotta be like you never really touched it. You don't want scratches or burrs," said Shane Love, lead welder and motor room fabricator for Joe Gibbs Racing, Huntersville, N.C. (see Figure 1).
An even more important role of the welds is to safeguard drivers, especially as they reach top speeds on the track.
"Someone can get killed if you don't have a proper weld," said Mickey Holmes, manager of motorsports marketing, The Lincoln Electric Co., Cleveland.
Welded race car parts include the chassis, spoilers, seat brackets, and the rear end housings connected to the upper and lower control arms.
Because so much welding is necessary, often everyone in a racing fabrication shop has to be able to weld.
"The bodies are all steel and have to be all tack-welded together," said Jon Moore, fabricator/welder for Roush Racing's Busch Series shop in Mooresville, N.C. (see Figure 2). "At some point everyone has to do some kind of welding, whether they tack in place or get it all welded together."
But before striking an arc, motorsports fabricators also must know metallurgy. In NASCAR®, for example, although car bodies, inner crush panels, and the chassis are steel, more and more exotic metals are being used as well. This creates more challenges for welders.
"There are different rules that apply to each type of material," Holmes said. "You have to keep the welders updated on the latest technology with the latest materials that are coming in."
Love added that it's important for welders to know their material and make sure they have the right equipment to work on it. This includes knowing not only what the material is, but also how it's made, if it's been heat-treated, what kinds of stresses will be on the part, and what filler material should be used (see "The fast and the filler metal").
"It used to be you put this race car on the track and go racing, and now you have to think about engineering," said Love, whose expertise is in specialty materials. "You're using different materials and different processes to make it hold up."
While many fabricators and engineers have their preferences, gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) are the two primary welding processes used in motorsports fabrication. In years past roll cages were welded using shielded metal arc welding (SMAW).
Like most racing fabrication shops, Roush uses both processes, but Moore said he favors GTAW because of its cleanness and precision.
Holmes said that GTAW has its benefits for motorsports fabrication.
"With TIG you get better control over your quality and less heat distortion," he said, adding that he's seen GTAW use increase in NASCAR. "The heat-affected zone is a little bit smaller so your chances of cracking lessen. It takes a lot more time, but you get less distortion, so it will hold tolerances better and the quality is higher."
Despite motorsports fabricators' preferences, each process is suited for different parts of a race car.
"Typically, as far as NASCAR goes, they use MIG to hang the sheet metal on the bodies. In the NHRA [National Hot Rod Association] and IRL [Indy Racing League], the majority is TIG-welded, [and] the chassis and everything in IRL is TIG-welded," Holmes said, adding that each racing league has its own fabrication rules.
John Patalak, special projects engineer for NASCAR, has found that both processes offer acceptable results. "We're getting similar results in testing between the two processes," he said.
While keeping drivers safe is paramount, so is the safety and health of workers fabricating and repairing race cars.
"It's huge," Love said of the safety aspect in the Joe Gibbs fabrication shop (see Figure 3). "We have systems from Lincoln Electric that have an automatic light on them and the arm comes down to the workpiece and pulls the smoke and fumes away from you. We also use the 3M helmet Speedglas system with an air blower."
In addition, fabricators at Joe Gibbs wear Carbonex™ clothing, a flame-retardant material that many drivers wear, to protect against heat and sparks.
Another aspect of safety—for drivers as well as welders—is the use of polyethylene foam, according to David Wirt, account executive for 3M's Automotive Aftermarket Division. Polyethylene foam can be used in various components of an automobile's interior.
To safeguard the driver, this foam absorbs impact. For the welder, it helps pinpoint gaps the welder missed, Wirt said.
As most racing fans know, the need for welding doesn't end when a race car hits the track. Crashes require teams to dissect race cars to figure out which parts have been affected and which ones have remained intact.
When a car comes back after a crash, it goes through a standard repair sequence.
According to Love, first the car is stripped down to the chassis and the body. Next the damaged body parts are removed. Then the car is bolted to the chassis plate. If, once it's bolted down, the car is in the same position it was in before leaving the fabrication shop, the car's structure is OK. If it isn't, broken or moved parts must be cut off. Then the rest of the work begins.
"When everything's in position, you start putting the pieces of the puzzle back together," Love said.
Although they're not common, on-site repairs at races can be challenging, Holmes said. Much of this is because the top fabricators in race shops who build the cars don't always travel with the teams.
Holmes said, however, that he's seeing more teams learn about welding and bring welders with them who are comfortable making repairs. Generally, he said teams travel with some equipment; for example, an inverter GTAW machine because it's lightweight and often lets fabricators do more than a standard machine allows.
No matter where the repair is made, how the welds hold up is particularly important, according to Don Fair, components leader for Chip Ganassi Racing, Concord, N.C.
"Everyone wants to know which parts failed and which held up. They all have ownership to their work," Fair said of the team's fabricators. "We use all the information we can to better ourselves each time. When parts of a wreck come back to our shop, we're all there to sort it out."
Bobby Hamilton Racing,www.bobbyhamiltonracing.com
Chip Ganassi Racing, www.chipganassiracing.com
Joe Gibbs Racing, www.joegibbsracing.com
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