Volume 8, Issue 6 - November/December 2006

Aluminum Cars Bring New Challenges for Technicians
More of the material is being used in vehicle bodies and it’s different than steel
by Les Shaver

You’re working on the back gate of a new Chevy Tahoe and you notice a white powder under the existing urethane. “No big deal,” you say, as you wipe off the offending powder. But it is a big deal, according to Mitch Becker, technical instructor for ABRA Auto Body and Glass, which is headquartered in Minneapolis.

“Most technicians just think it’s a white powder or a simple contamination,” Becker explained. “They wipe it off and prime over the area. That’s called filiform corrosion. Just as a rusted pinchweld needs to be corrected, so does this type of corrosion on aluminum. Failure to do so will allow it to spread.”

Auto glass technicians need to become familiar with aluminum and all the issues that come with it, because there’s more on the way, according to Becker. Auto manufacturers are increasing their use of aluminum in vehicle design because of the weight savings it brings. 

“We have aluminum-intensive vehicles coming from all directions,” Becker pointed out. “We’re going to see a lot more aluminum outer panels and interior panels. There’s just no way around it. The car world has changed dramatically. Glass technicians need to know what the pinchweld metal is. We also need to know the limitations of that metal.”

From Coke Can to Quarter Panel
Aluminum has been used in soda cans for years. While that seems a long way from being an integral part of the body of an automobile, if you’ve been watching trends with materials over the past few years, the increased usage of aluminum in vehicles shouldn’t be a surprise.

Steel’s primary advantage over aluminum has always been cost. Steel was cheap to manufacture, while aluminum remained expensive to produce from raw materials. 

However, the availability of more and more recycled aluminum has made the process much cheaper, he added, because recycled aluminum is 50 percent cheaper to manufacture than steel.

“With the heating costs, fuel costs and everything else, that’s a huge factor in using aluminum versus steel,” Becker said. “Steel requires so much heat while aluminum requires very little. Car manufacturers began using it in the car manufacturing process and now they swallow up this recycled aluminum as fast as they can get it.”

Vehicle manufacturers also are realizing many other benefits. For one, aluminum is lighter than steel, yet just as strong. This gives manufacturers a pleasant choice of either saving weight and fuel or adding new gadgets.

“You can be a lighter weight and use less fuel or you can take out a certain amount of weight to add other features,” explained Lynne Karabin whose company, Aluminum Consulting, is located in Pittsburgh. “Weight savings is fuels savings. Weight savings also allows you to add certain safety features without going over a weight limit such as airbags or anti-lock brakes.”

There are design advantages as well.

“When manufacturing vehicles, the manufacturers put in crush and crumple zones to absorb energy in a crash,” Becker said. “To make steel parts fold, the vehicle manufacturer must put holes or indentations in the steel to “trigger” crushing. In cars using aluminum, manufacturers don’t have to put in “trigger” points. Aluminum has a natural folding process built in. They save money in manufacturing because there is less forming of parts.” 

The Installer’s Challenge
The use of aluminum is a drastic change in vehicle components. Is there any question that it will bring major changes for body shops and auto glass technicians? Technicians must be prepared for the difference in terms of corrosion.

“Many of the corrosion principles of steel are completely different with aluminum,” Becker explained. “You don’t have red rust with aluminum. If there is a white powder, that’s corrosion, the aluminum version of rust. Untreated filiform corrosion spreads faster than rust does.”

Another key issue for auto glass technicians is that aluminum and steel don’t mix well. 

“When an aluminum vehicle comes into our body shop, if we have to expose it to the bare metal, that means we have to take the paint and the primer off,” Becker said. “We can’t take that vehicle anywhere near a steel vehicle. Steel and aluminum are counter productive metals. They do not react well together at all.” 

“Another factor with aluminum vehicles is galvanic corrosion, which occurs whenever two dissimilar metals are in contact with moisture (which serves as an electrolyte),” explained Bob Jansen, senior instructional designer for I-CAR, a training organization for collision industry professionals in Hoffman Estates, Ill. “Using a nonconductive urethane resists galvanic corrosion for the same reasons.”

Technicians at ABRA Auto Body and Glass keep tools used on steel and aluminum vehicles separate from each other. If a tool is used on an aluminum car, it must be kept in a separate toolbox from the tools used on steel cars.

“If someone thinks they’re going to take the corrosion out by taking a grinder to the aluminum, they’ll go right through it like butter,” Becker said. 

Technicians not only have to be careful with where the tools were used before they work on aluminum, but they also must be wary of how they use the tools. A steel razor blade scratching aluminum is not a good thing.

“It’s not only a problem with a power tool, but also using a bow knife or a razor knife,” explained Gilbert Gutierrez, vice president of sales for Equalizer Industries, a tool manufacturer in Round Rock, Texas. 

Tool manufacturers are very aware of the dangers of having steel blades dig into aluminum on cars. Equalizer Industries is working on new products to address these problems, but for competitive reasons it won’t reveal what it has planned yet.

According to Gutierrez, “We’re making special blades. Steel blades can be a problem. We’re working on something that will help technicians pull the windshield out and help keep them from creating a problem.”

Others warn of problems as well.

“You have to be extra careful about scratches with aluminum because it oxidizes so aggressively,” said Dale Malcolm, technical services supervisor for Dow Automotive in Dayton, Ohio. “A lot of times people think the paint is peeling off an aluminum body vehicle because it’s bad paint. Actually someone scratched it and it’s oxidizing out under the paint. The paint is coming off in large sections. It’s a corrosion issue, not a bonding issue.”

I-CAR’s Jansen points to another situation.

“Since aluminum is so much more highly conductive than steel, most aluminum vehicle makers recommend a nonconductive adhesive, primarily with the backlite more than the windshield, but with some windshields as well,” Jansen said. “Most urethanes are conductive, since their basic composition is carbon. That wreaks havoc with the electronics in pinchwelds, primarily antenna signals, cell phone antennas, and GPS.”

Malcolm, however, warns technicians not to fall into the trap of thinking that a non-conductive urethane will stop corrosion.

“A non-conductive urethane on an aluminum body won’t stop corrosion,” Malcolm stressed. “It will just keep the urethane from contributing to it. The standard conductive urethane contributes to the corrosion.”

Pinchweld primers are also a concern. The primers glass shops use normally won’t work. They must have a primer that keeps the oxygen out.

“We do have a bare metal primer that we’re starting to recommend for use on aluminum body vehicles over scratches,” Malcolm added. “If you scratch an aluminum vehicle and put a pure lacquer over it, it will keep the oxygen out. It doesn’t matter what you put over it as long as it keeps the oxygen out.”

Les Shaver is a contributing editor to AGRR.

Several factors fueling use of recycled auto glass

Is the time right for recycled glass?
In the past it was just a body shop trend. But now, to the dismay of many auto glass shops, the movement of insurance companies writing checks directly to their customers (and cutting glass shops out of the loop) is coming to their industry. 

“Now with insurance companies writing checks for the full replacement cost to people filing claims, the insured will shop around for a good deal; buying and using a recycled original equipment glass unit would be cheaper and they may pocket the difference,” warned Mitch Becker, technical instructor for ABRA Auto Body and Glass in Brooklyn Center, Minn.

The Automotive Recyclers Association (ARA) is making it easy for consumers to find these sorts of recycled parts through its vast network. Many recyclers already carry the most popular windshields in stock as well as an inventory of aftermarket brands or, in some cases, an original equipment (OE) brand of glass. (It must be pointed out that there is not a big demand for used windshields yet.) 

“A customer will call to see if they have the part for the vehicle; if they do, it is an easy sale,” Becker said. “The parts they don’t have, recyclers go to the Internet and find out who does have it. Once located, it can be sent to them very quickly. Large recycling companies have large shipping departments that can ship huge quantities of auto parts back and forth. If the customer is willing to wait a day, then the glass will be shipped to the business.” 

Calling for Installing
According to Becker it’s common for customers to call and ask glass shops to install these pieces of glass, which takes away from the profit the shops earn by marking up the glass.
Insurance companies also have started asking for it. “If there is a quarter glass on a 2002 Chevy Suburban damaged in a collision, the insurance company can and does request that a recycled part be used,” Becker said. “New glass may cost $800, but a recycler may sell the glass for $200. The justification is that as long as it is an OE part from the recycler and is from a vehicle that is the same year, or newer, as the damaged vehicle, then they have satisfied the insurance policy for repairing that vehicle. They use doors, hoods, fenders and engines this way.” 

Getting a used door glass or a back glass is one thing. But windshields are a totally different arena because of the safety. With used glass, auto glass installers don’t know how it was bonded to the old vehicle or what it was exposed to. This means installers can’t guarantee that it will make a proper installation on the new vehicle. 

The Auto Glass Replacement Safety Standards Council (AGRSS) has issued a ruling that allows recycled glass, but only if it’s free of structural flaws, sound and free of flaws, free of chips, edge chips, cracks or breaks, free of any signs of delamination, free of distortion in the driver’s field of vision, if the installer knows the type of retention system used and if that retention system is compatible with the original equipment design, if the installer knows the type of adhesive system used on the previous installation and if the manufacturer of the adhesive system that is going to be used permits its use with the installation of recycled or used glass. 

If the insurers and ARA start pushing for used windshields, Becker expects the auto glass industry to draw a line in the sand. “As far as windshields are concerned, we’re fighting back,” Becker said. “We’ve told the insurance company we can’t take on liability for a piece of glass that we don’t have any control of. In most cases, they’re fine with that, but we’ve lost about 10 jobs.”

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