Top 7 Causes of Peeling Paint
1. Surface contamination. Any dirt or contaminants on a surface prevent the coating from obtaining optimum adhesion to the substrate. Water based coatings are greatly affected by grease and oil contamination.
2. Surface temperature. The surface was too hot when the coating was applied. This forces off the solvent in the paint too quickly causing the paint to not adhere as it should.
3. A coating is not compatible with the substrate. This mostly occurs when oil based coatings are applied to galvanized steel or concrete. A chemical reaction occurs and breaks down the adhesion bond.
4. A coating is not compatible with an existing coating. This generally occurs when applying a coating over an existing epoxy, polyurethane, or other type of chemically cured coating.
5. Age. The cohesive bond strength within a coating continues to develop over the lifetime of a coating and at some point it can overwhelm the adhesive strength of the coating. That’s why peeling paint curls.
6. Moisture. Moisture transmission through a concrete or wood substrate causes the coating to not adhere. It's forced off by the moisture coming through the substrate.
7. The surface is too smooth. The lack of any surface profile eliminates the development of mechanical adhesion with the substrate. Sanding extremely glossy surfaces will promote adhesion of the coating.