Method for coating light alloy rims

A method for coating light alloy rims, the method comprising:

• applying a primer (A) layer directly on a machined light alloy rim blank comprising a cast aluminum alloy, the primer (A) layer comprising at least one radiation-curable coating material having an acid number in accordance with DIN EN ISO 3682 (by potentiometry) of 10 to 120 mg KOH/g;
• after applying the primer (A) layer, applying a base coat (B) layer;
• after applying the base coat (B) layer, applying a radiation-curable clear coat (C) layer on an outside surface of the light alloy rim, the clear coat (C) layer having a double-bond density of free-radically polymerizable reactive groups per unit mass of coating material of at least 1 mol/kg;
• and
• curing the primer (A) layer, the clear coat (C) layer, and optionally the base coat (B) layer by high-energy radiation selected from the group consisting of light in the wavelength range of 200 nm to 700 nm, an electron beam in the range of 150 keV to 300 keV, and combinations thereof;
• wherein:
• the primer (A) layer is fully cured with the high-energy radiation and without being further heated after being applied;
• and
• the primer (A) layer, the base coat (B) layer, and the clear coat (C) layer are different from each other.