1. Deep Drawing
Power and precision are needed to shape a spare body part out of a piece of metal sheeting. Even the tools used by the experts are impressive. They are 2.4 m long, 1.6 m wide, 1.7 m high and weigh 14 metric tons. The sheet is tensioned using a die and clamp and deep drawn over the stamp. Up to 800 metric tons of pressing force are applied to the sheet to achieve the basic shape.
A single targeted cut is not enough to separate the surplus material from the basic shape. Merely to produce an exact cut, the tool must be relocated four times and the fender section reclamped for stamping out. Three extra steps are needed for the subsequent folding and punching. Ten process steps, including deep drawing, are required to produce a finished fender section which can be worked on further.
It is at this point that the hot phase of fender production starts. Experts accurately position the front and rear sections of the fender in a special jig. The temperature rises to 5,800 degrees Fahrenheit during the subsequent gas welding process, forming an unbreakable bond with a stable welded seam.
4. Buffing the Welded Seam
Any irregularities in the thickness of the welded seam must be removed. The grinder is used as a first step on the way to a flat and homogeneous surface. Then the seam is roughly buffed.
5. Finishing the Welded Seam
This requires a steady hand and a good eye, in order to finish off the work on the welded seam. The fender interface is flattened using special tools and gone over with the body plane to produce a homogeneous surface, but one which is not yet suitable for painting.
6. Surface Finish
Grinding, grinding, grinding – a great deal of patience and four to five grinding processes in increasingly fine gradations are necessary during the surface finish stage in order to end up with a surface suitable for painting.
7. Producing the Add-On Parts
While the fender is being shaped, experts are already working in parallel to manufacture the necessary add-on parts. Depending on type, a single fender can be made up of over 60 parts. These include the headlight recess, tank tray, tank cap and filler plate.
The key add-on parts are then adapted with the help of original jigs and tools in order to complete the fender. The experts use traditional procedures which require special skills during this process. Spot welding, metal active gas (MAG) welding or hard soldering – the specialists use the right technique for each add-on part. Once the tank tray has been fitted, the exclusive craftsmanship is finished and the completed fender is ready to be added to the vehicle.