In the never-ending search for lighter and stronger materials, a growing number of automakers are turning to aluminum alloy as an alternative to traditional steel. As a result, auto body shops and dealerships across the U.S. are faced with the prospect of potentially tougher and more expensive repairs. But exactly how difficult is it to repair an aluminum body or chassis and how does that affect a typical collision repair shop's ability to repair it?
How Aluminum Differs from Steel
Highly valued for its lightness and strength, aluminum is a much different metal from typical steel in many ways. These differences are further highlighted during vehicle repairs:
- Aluminum lacks the metal memory of conventional steel—While steel body panels can be reworked into their original shapes with enough time and skill, aluminum body panels may stretch and weaken under the stress.
- Aluminum reacts differently to heat than typical steel—Heat travels faster through aluminum, making ordinary welds too hot to effectively hold a bond between surfaces. This problem is usually bypassed with the use of rivets and adhesives.
- Unfinished aluminum and steel can't be welded together—Attempts to join aluminum and steel together usually result in galvanic corrosion for aluminum and severe rust for steel.
Even different types of aluminum can behave differently based on their individual properties. According to Mitch Baker of Body Shop Business, high-temper aluminum behaves much like high-strength steel, sharing the steel's exceptional strength as well as its brittleness when compared to other metals. Low-temper aluminum is much softer and easier to shape. Most automotive applications rely on aluminum alloys that split the difference between low-temper and high-temper aluminum.
Special Tools and Training Are Often Needed for Repairs
As the use of aluminum alloys in mainstream vehicle manufacturing becomes commonplace, manufacturers are encouraging dealers and independent collision repair facilities to prepare themselves through comprehensive training and equipment upgrades.
For example, Ford has trained over 750 dealerships and 800 independent auto body shops on repairing aluminum vehicles like the top-selling F-150 pickup truck. Despite being comprehensive, the training has helped reduce the overall difficulty of repairing aluminum body panels and other structural components. Some automotive manufacturers are also sharing technical data on their aluminum vehicles in order to ease and speed up repair efforts.
In addition to specialized training and information, auto body repair services are also bringing in equipment specifically designed with aluminum body and chassis repair in mind. The advent of this new equipment enhances an auto body shop's ability to make aluminum repairs, but it could also add cost to the repair process.
Special Issues With Repairing Aluminum
There are a number of special issues with repairing aluminum body panels that may not pop up when dealing with conventional steel panels:
Cross-contamination—Whether it's iron oxide dust settling on aluminum panels or aluminum dust settling on steel panels, cross-contamination can cause poor paint adhesion and other quality issues. Using dividers and curtains to isolate areas where aluminum repairs occur can be an effective method of reducing cross-contamination.
Combustion hazards—Aluminum dust can also pose a combustion hazard in large concentrations. It's important to explore safe, non-combustible methods of capturing and containing aluminum dust in order to reduce this hazard and increase overall safety.
Parts and materials availability—High-volume demand for certain vehicles made with aluminum alloys can also mean a tight supply chain for parts makers. Parts shortages can complicate aluminum repairs, especially if specialized parts are required for the repair process.
The actual process of repairing vehicles built from aluminum alloy is difficult in many respects, but those difficulties are being mitigated with time, training and the development of innovative repair techniques. Eventually, repairing a vehicle made entirely of aluminum will be as straightforward as repairing a similar vehicle made from conventional steel.