by Douglas Craig, Structural Adhesives Applications Engineering Manager & Collision Repair Industry Liaison
Many demands are placed on modern vehicles. They need to meet targets for fuel economy and government-mandated emissions requirements as well as accommodate customer demand for performance. Fortunately, these goals can all be advanced by employing a single strategy: using lighter weight materials—such as aluminum—for vehicle construction.
Once used only on high-end vehicles, aluminum is coming into wider use as a substrate because technological advances in manufacturing are making it easier to work with the material and also bringing costs down. The Ford Motor Company pioneered aluminum-bodied pickup trucks starting with its F-150 pickup truck in 2014. The success of that model helped aluminum become established as a safe, viable alternative to traditional all-steel vehicles. It weighed up to 700 pounds less than previous all-steel models and offered improved fuel efficiency along with better acceleration, braking and handling. In 2017, Ford released its Super Duty® truck, which features a high-strength, military-grade aluminum alloy body that offers an additional 350 pound weight savings.
Aluminum and collision repair key steps to success
Just as happened with previous changes to vehicle body composition—think the introduction of plastics in the 1960s—repair technicians may face a minor learning curve when working with aluminum substrates. However, a few key steps will lead to success when repairing these vehicle components:
• Determine the grade of aluminum.
The Aluminum Association established the wrought alloy designation system more than 60 years ago. At that time their list included 75 unique chemical compositions. Today, there are more than 530 registered active compositions and that number continues to grow. Elements commonly alloyed with aluminum include iron, silicon, copper, magnesium, manganese and zinc; these may make up as much as 15 percent of the alloy by weight. Alloys are assigned a four-digit number, in which the first digit identifies a general class, or series, characterized by its main alloying elements.
• Check with the original equipment manufacturer (OEM).
Since the collision repair industry collectively decided that the vehicle manufacturer should provide the repair standards and guidelines, OEMs have continued to become more involved in disseminating repair information to body shops. They have an interest in making sure that their vehicles are repaired properly and returned to “pre-loss” condition. They also recognize that the repair parts channel can be a profit center. Consequently, they are recommending the use of OEM-approved replacement parts and products. Product suppliers can also be a good source of information on which products are specified by an OEM and how to use the products to make a successful repair.
• Beware of "equivalents."
Equivalency cannot be determined just by reading the package label on a tube of adhesive or sealant. If the wrong product is used, the repair could be prone to failure. A product supplier can confirm whether an equivalent product has the same formulation as an OEM-recommended product.
• Avoid cross contamination.
Steel metallic dust or grinder sparks can deposit fine steel particles on exposed aluminum. These particles are extremely corrosive to aluminum alloys, especially if moisture is present. Therefore, it is necessary to isolate steel and aluminum repair work areas by using shop curtains or performing these procedures in separate work areas. A separate set of tools should be used for working on steel and aluminum parts. Dust removal or extraction equipment can also prevent cross-contamination. Typically, these systems involve attaching sanding and grinding tools to a vacuum system.
Resources are available to technicians for additional information and training. I-CAR, short for the Inter-Industry Conference on Auto Collision Repair, is an international, not-for-profit organization dedicated to providing the information, knowledge and skills required to perform complete, safe and quality repairs. Its Industry Training Alliance awards credit hours that can be applied towards I-CAR Gold Class Professional and Platinum Individual designations. I-CAR’s training programs cover all aspects of vehicle repair, with several courses geared specifically for repairing aluminum-bodied automobiles and trucks. When the Ford F-150 truck was introduced, Ford and I-CAR developed training programs including “Aluminum Exterior Panel Repair and Replacement,” that addressed the unique processes associated with aluminum repair.
As OEM manufacturers increase their use of aluminum, collision repair shops will need to become proficient in repairing components with aluminum substrates. Basic repair techniques and products are similar to those used for steel and plastic substrates. With proper training and careful attention to following OEM guidelines and standard operating procedures (SOPs), collision repair shops can successfully make aluminum parts look as good as new.