Why Do Coil Coatings Fail?
Key facts
| Cause | How it shows | Prevention |
|---|---|---|
| Under-cure | Soft film, poor adhesion, early flaking | Logged cure temperature and time |
| Contamination | Blistering, peeling | Degreasing, rinse and drying record |
| Missed areas | Corrosion at collars and joints | Dip coating, coverage inspection |
| Wrong system | Attack by acids, H₂S or chemicals | Site review before selection |
| Mechanical damage | Local corrosion at scratches | Packing, careful installation, touch-up |
| Harsh cleaning | Film worn off fin faces | Low-pressure water, neutral cleaners |
Under-cure comes first
A coating that has not reached its full cure stays soft and loses adhesion, and fails salt exposure early. PG-S1’s data sheet warns about this directly, which is why the cure record is a required QC item.
Surface preparation
Oil from fin stamping and dirt from storage stop the coating from bonding. Coils are degreased, rinsed and dried before coating.
Coverage
A coating sprayed on the faces can miss the collars and joints deep in the coil, where corrosion starts.
Selection and use
A thin film in a chemical environment, or a coil cleaned with high-pressure water every month, will not reach its expected life.
What this means for your project
Ask for the cure record and coverage inspection in the batch report, share site conditions at the selection stage, and give installers and maintenance teams the handling and cleaning rules.
