PART 1) Before POSST steel frames are painted, they receive a comprehensive pre-treatment known as cathodic electro deposition. This involves creating an electric circuit where the frame holds a negative charge and the coating (suspended in a liquid) holds a positive charge.
This process results in the frame being exceptionally resistant to rust, both inside and out. This treatment is unique within bicycle frame-building, and followed by top-quality frame producers. It’s a detail that makes the main difference in whether a frame rusts in later years, or not. All other cavity sealing processes (e.g. wax) don’t have anything like the same durability, and in terms of corrosion protection don’t even come close.
After the electro deposition stage, the frame is given a series of coating, both powder and wet paint which we will cover in a separate post.
PART 2) After the electro deposition stage, the frame is given a series of coating, both powder and wet paint.
The powder coating is done using pure epoxy. They are considered among the best in terms of corrosion and chemical resistance. We know they do not function well when subjected to the sun, but as a precoat underneath the wet paint there is no issue. This covers its weaknesses and utilizes its strengths at the same time.
Later the frames are finished with layers of primer, basecoat, top coat and clear coating. We use VOC-compliant paints from CROMAX, a global brand from Axalta Coating System formally DuPont Performance Coatings.