Frame painting. Ηλεκτροστατική βαφή πλαισίου (karikas.gr).

First attempt with epoxy primer for aluminum.

Looks ok but...it isn't!

Final, frame painting made from professionals.
(ηλεκτροστατικές βαφές www.karikas.gr)
Electrostatic coating is a manufacturing process that employs charged particles to more efficiently paint a workpiece. Paint, in the form of either powdered particles or atomized liquid, is initially projected towards a conductive workpiece using normal spraying methods, and is then accelerated toward the workpiece by a powerful electrostatic charge.