New Oulu paint shop proves high quality in the X40 train painting process

A modernisation project has high quality requirements and specific expertise is needed in every aspect of the project. Especially the Oulu surface treatment department has encountered new kinds of challenges to solve as a result of the project. 

The painting process itself is the same for all types of vehicles. When a train arrives for surface treatment, it first goes to the washing hall, where the surface is cleaned for pre-treatment. Loose parts, such as hatches and doors, are removed from the train body, and the pre-treatment involves sanding the old paintwork and repairing any corrosion damage or dents. 

The actual painting work is done in the painting chamber. The body and the loose parts are given their respective coats of paint; a topcoat is applied on top of the primer and finally the parts are varnished. Once the train body and all the parts have been painted, it is ready to be reassembled, and the surface treatment process is complete.

Overcoming challenges develops professional skills 

X40 trains are painted in four different colours: dark grey, black, green and silver metallic paint. Metallic paints have been used for decades in car painting but are much less common in industrial painting. The project has required the Oulu surface treatment line to develop the right methods for spraying the paint to achieve the desired quality and finish. 

“A challenging but rewarding journey — the surface treatment process is refined to a high standard, and the aim is even higher.” 

In addition to the metallic paint, the multi-colour nature of train carriages makes the surface treatment more complex. All colour boundaries are razor-sharp, which can only be achieved by carefully planning each step of the process so that areas already painted can be accurately protected without mixing different paints. 

High quality is ensured by closely monitoring each step of the process and its outcome. During the painting process, measurements are taken, for example, on surface smoothness, colour matching, paint film thickness and gloss level of the paint surface. 

Surface Treatment Specialist Harri Junnila is happy with the progress of the project: "The ramp-up of the new surface treatment shop in Oulu and the painting of the X40 trains have been partly two separate projects, which finally came together nicely. It has been a very interesting and educational journey, and we have managed to refine the demanding surface treatment process to a high level of quality. It has been a great challenge for me and the organisation, and there is still a lot of work to be done as we want to make sure that the process improves even further." 

Continuous improvement and method development is part of the process. The X40 train, which will enter series production in early 2025, was test painted during the previous year and the improved quality of the project has expanded the concept of excellence in industrial painting. This will also be of great benefit for future rolling stock projects.

Nice-to-know facts about the Oulu surface treatment facility

• New surface treatment line completed in 2024 
• Pre-treatment hall and two painting chambers 
  • Width 7 metres
  • Height 8 metres
  • Combined length of almost 100 metres

• Intelligent temperature, humidity and ventilation control 
• Suitable for fleet projects and subcontracting painting 
• VR FleetCare has paint shops in Oulu and Pieksämäki