This tank wagon is not even ten years old.
In the photo it looks like normal ageing. In reality the coating is gradually wearing away. Not in flakes, but over the whole surface and unevenly. On a large part of the shell the primer is already showing through.
The cause is a combination of two things. During manufacturing the painting procedure was not followed: surface preparation, layer thickness, drying times. That does not show in the first years. Then operation comes in. The tank is filled, the temperature changes, the shell works. A coating without a properly prepared base cannot withstand it.
You can see the result for yourself.
At the revision you then face a decision that cannot be settled by ticking a box. The question is not whether it passes today. It is what it will look like in four years, when the wagon comes in for its next revision.
When a coating wears away at this rate, sooner or later it stops doing its job. And protecting the tank shell is no longer a cosmetic matter.
That is why on these wagons we assess the condition of the coating separately, not as an item on a checklist. Sometimes that means recommending action earlier than anyone would expect.
Eighteen years in this field have taught me one thing. A mistake made in production never disappears. It just waits until it is most expensive to fix.