What causes peeling when applied to plated items? Identifying the substrate.
When painted over the plating, it peeled off. This explains the adhesion conditions for each type of plating and the points to check before acceptance.
When painted over plated items, the coating peeled off later. This is not due to the paint, but rather the nature of the substrate. ────────────── ■ Cause of Occurrence The surface of the plating is smooth, lacking the irregularities for the coating to adhere to. Additionally, if chromate or rust prevention oil remains, it will repel the coating. ■ Truth Zinc plating develops white rust over time, and when painted over, it peels off in layers. Hot-dip galvanized surfaces are hard, and simply degreasing is not enough for adhesion. The necessary surface preparation varies depending on the type of plating and the number of days that have passed. ■ Improvement Measures We will first communicate the type of plating, the number of days since plating, and whether rust prevention treatment has been applied. If necessary, we will ensure adhesion through sanding or using a dedicated primer. Eiwa Kogei responds from the pre-acceptance inspection of plated items.
basic information
Base material: Zinc plating, hot-dip galvanized, anodized, chemical treatment products / Surface preparation: Degreasing, surface roughening, dedicated primer / Confirmation items: Type of plating, elapsed days, presence of rust prevention treatment / Film thickness: 20-40 microns
Price range
Delivery Time
Applications/Examples of results
Metallic baked coating on parts after plating, such as zinc plating, hot-dip galvanized, and electrogalvanized products. The selection of the undercoating treatment is based on the type of plating and the number of days elapsed.
Related Videos
catalog（3）
Download All Catalogs
Distributors
We are not just a "subcontracted painting factory." Established in 1958, our company has a foundation of painting technology and also specializes in chemical treatment, stripping, and cleaning, functioning as the "external surface treatment department" in your organizational chart. Based on our philosophy of "preparation is eight-tenths of the work," we emphasize participation from the "upstream process" before the drawings are finalized. We conduct test painting on a wide range of metals and difficult materials, and we produce the entire process from assembly, packaging, to delivery, thereby reducing your management workload. Additionally, by being able to perform zinc phosphate treatment in-house, we achieve stable painting quality. Furthermore, our micro-heating stripping technology, which does not use chemicals, maintains the electrical state of the "jigs (hangers)" that influence painting quality. Our approach of "pre-treatment determines painting quality" ensures the stability of the paint film during mass production. Rather than simply "applying specified standards," we work backwards to achieve optimal painting specifications and prevent scratches during transportation, sparing no effort in thorough discussions from the outset. This diligent preparation is the shortest path to preventing rework and minimizing total costs. From the development stage, please utilize the expertise of our specialists as part of your production line.