Automobiles and motorcycles feature some of the most complex paint work anywhere. Not only do the coatings have to look great from bumper to bumper, the paint must also hold up well against sun damage, wind, and rain, while also preventing rust and corrosion of the substrate for years on end. Properly painting a car, truck, or motorcycle requires some of the most complex layering of paint and protective coating of any product or structure. But long before the first sprayer starts painting, the surface must be properly prepared. One of the world’s most popular motorcycle manufacturers, Harley Davidson, has a unique approach to surface preparation that blends robotic precision with human craftwork.

Getting a gas tank to look this good is a multi-step process.
Image courtesy of 61Harley.com

From tailpipes being chrome plated to gas tanks needing a color coat, the number of pieces of a motorcycle that must be coated in some fashion is extensive. Surface preparation for motorcycle painting is a complicated, multi-step process for each part. For example, motorcycle gas tanks at the Harley Davidson factory undergo rigorous preparation before receiving their paint job. In some cases, the gas tanks will go through a twelve step process before being deemed ready for assembly.

To begin preparing the tank to receive paint, an industrial robot uses a series of sanders to smooth the surface of the gas tank. The robot is programmed by a technician that automates each specific angle and movement prior to the work beginning. As the robot holds the tank against different buffer wheels at different angles for different durations of time, surface imperfections and weld joints are smoothed out.

A Harley Davidson gas tank not yet prepared for painting.
Image courtesy of Amazon.

In this case, the robot is performing a series of programmed actions and is not capable of processing feedback and making adjustments. While some paint automation tools do indeed evaluate the substrate and coating as the work is being done, the tool Harley Davidson utilizes does not. This is an important detail, as it demonstrates that even with machines taking over more and more tasks in industrial manufacturing (including painting), there are still elements of the work that must be performed by skilled human hands. After the automated buffing is complete, a human takes over. Trained technicians hand sand the tanks to work out any imperfections not addressed by the robot. By the time the hand sanding is completed, the surface of the tank is smooth and clear of any flakes or tactile imperfections.

Once the surface is smooth, the gas tank is sandblasted and air-cleaned to give the surface a universal texture that is not only visually appealing, but also coarse enough to allow for adhesion with the first coats of paint about to be applied. Having the surface and shape of the tank meet exacting standards prior to being painted is how Harley Davidson ensures that the final coated gas tank will be perfect every time. The painting itself is once again a combination of robotic automation and human interaction. In some cases, there are even multiple layers each of the base coat, top coat, and clear coat that contribute to the clear and glossy finish of the final product.

Thie finished product at the Harley Davidson factory.
Image courtesy of Leather Up.

When we think about automation in professional painting, we usually think of paint rooms and robotic sprayers. But paint robotics extend further to include tasks like surface preparation before the paint work even begins. Harley Davidson is just one manufacturer that combines human artistic and technical expertise with robotics. Like many other companies in the automotive industry, they’ve found a great solution that keeps their assembly lines running and customers happy without eliminating the handcrafting that makes their products unique. Click here to learn more more about industrial paint automation and its effects on professional painters!