How to Repair Aluminum Body Panels
What makes a body shop like Cline Collision Center unique, is that not all aluminum is the same, but we know how to work with each type. Different vehicle manufacturers use different types of aluminum with different alloys, along with characteristics. There’re multiple ways to repair an aluminum panel, which is why the Ford Certified Body Shop Program exists- to help shops learn the differences and how to work with each of them. Why do aluminum panels exist anyway? They promote better fuel economy. Everyone loves to save on gas!
Aluminum behaves differently than steel. Once it is reshaped it forgets its original form and will take on a new shape, unlike a steel part that will remember the form it used to be in. It is a work hardened material. When aluminum is stamped into shape it becomes stronger. After the panel is bent in a collision it becomes stronger. Flex it too much and it breaks or cracks, like a bent spoon. To repair and pull the damaged area, the panel must be heated to 400°F to allow the metal to soften. Aluminum dissipates heat very quickly but can become permanently changed if heated past a certain point, and that point is approximately 750°F. The heated panel can now be pulled and while pulling the material it is being work hardened to set the new memory of the collision repair.
A thin coating of aluminum oxide forms after being exposed to the air in as little as 15 minutes. This oxidation has a much higher melting temperature than the original aluminum material and a stud will not fuse correctly to the panel. Aluminum’s melting point is 1,200°F and aluminum oxide is 3,700°F. The oxide can be removed using a stainless-steel brush.
A few tools you will need are an abrasive grinding disc, inline removal tool and stainless-steel brushes to remove the paint and oxide coating. To shape the metal, it must be softened. Heat to the to the appropriate temperature with a digital temperature set heat gun for heat control. Aluminum has a high thermal conductivity and heat travels throughout the panel rather than in a concentrated spot. Some technicians use the aid of coworker to heat the area while the other uses the dent pulling tool. If you go above 750°F the structural rigidity of the part could be permanently annealed.
As you can see there’s a lot that goes into aluminum body repair. Trust the pros at Cline Collision Center to get the job done right the first time!