Why Doesn't Spray Paint Prevent Rust?
2 Answers
It can achieve a certain rust prevention effect. Extended information is as follows: 1. Introduction: Spray paint, also known as aerosol paint, typically consists of an aerosol can, aerosol valve, contents (paint), and propellant. It is a type of paint that is processed through special methods and filled under high pressure for easy spraying, also referred to as manual spray paint. 2. Uses: Spray paint has extremely wide applications. With recent economic development, its uses have expanded from initially repairing paint flaws to molds, industrial machinery, toys, crafts, musical instruments, buildings, steel structures, advertising and promotional industries, signage, graffiti, and various other industries. Even in less industrialized pastoral areas, spray paint is used, reportedly to distinguish livestock herds of different farmers by color.
I've been fixing cars for over 20 years, and I've seen countless cases where spray paint fails to prevent rust. To put it bluntly, it's just a temporary emergency solution—the coating is as thin as paper, easily penetrated by wind and rain. Real rust-proof paint needs ingredients like zinc powder or iron oxide red, while spray paint is basically just a layer of resin-based color paint. Another major flaw is its poor adhesion; if you get a bit of dust or don't clean the surface properly, moisture gets trapped under the paint film. The most extreme case I've seen was a car owner who used spray paint for a repair, and within three months, the entire door panel was covered in rust bubbles. Professional painting requires phosphating treatment and three layers of paint: primer to fill small dents, a middle layer for corrosion resistance, and a topcoat to withstand UV rays—all these steps are skipped with a spray can.
