Toby Chess focuses ASA-CO classes on repair of new materials
Westminster, Colo.—Driven mainly by modern motorists’ safety expectations and Corporate Average Fuel Economy (CAFE) standards, many automakers are now using high-strength steel unibodies, structural adhesives, and aluminum, magnesium and carbon fiber panels, creating new complexities in collision repair, I-CAR instructor Toby Chess told a group of collision repair shop personnel at the Independent Automotive Professionals Symposium at the Westin Westminster on Jan. 28.
During the one-day event, hosted by the Automotive Service Association of Colorado (ASA-CO), attendees had the opportunity to participate in two of Chess’ I-CAR-certified courses: Exterior Panels Damage Analysis (Estimator DAM10) and Steel Unitized Structures Technologies (Body Tech SPS07).
“CAFE standards will drive the use of more advanced steels,” Chess said, adding that repair procedures and welding techniques differ greatly on those cars, when compared with older models primarily constructed of mild steel.
Instead of welds, some automakers use structural adhesives, he said, which are extremely strong and lightweight, Chess said. More and more automakers are using aluminum hoods, he added, pointing out that the easiest way to identify that a panel is aluminum is by using a magnet at the time of the estimate.
Many insurance adjusters will say that aluminum is non-repairable, which isn’t true, Chess said.
“Aluminum has no memory and will not pop back into its old position,” Chess said. Annealing is a repair technique in which aluminum, when heated, becomes softened and malleable, he said — but he warned that if it’s heated to 600 F, it becomes permanently soft. The ideal temperature range, he said, is between 400 F and 570 F.
There are a few spot welders on the market today that will identify the type and thickness of steel a bodyman is working on, Chess said.
Some use pulse weld technology, he said, that preheats the metal with a pulsation prior to applying the weld. “It reduces the heat necessary to perform the weld.”
When cutting panels, Chess warned the audience to be aware of structural foam, which can be as hard as concrete. If melted, he said, it releases cyanide gas and CO2 that can be harmful when inhaled.
Safety features such as door intrusion beams should not be repaired, he said, because doing so can compromise the protection of occupants in the event of a collision that impacts the side of the vehicle.
“Energy transfer occurs on the sides of the car,” Chess said. If a car is struck on the B-pillar, transferred energy will travel across the roof to the other side of the car, he added. To conduct a thorough repair, he said, the upper points of the car should be measured.
Automakers, such as Toyota, will manufacture a car with a range of acceptable tolerances of plus- or minus-three, Chess said. “So the repair has to be zero, because if it isn’t it could be out of allowable factory tolerances.”
All automakers today are using seam sealers, he said, which can be expensive and hard to get insurance companies to pay for. To illustrate to adjusters the amount used, simply run a rope along the repair where the seam sealer was used and charge by the inch.