Poor Adhesion

Poor Adhesion: Between the topcoat and primer, between the topcoat and aged paint, or between the primer and bare surface.

Causes

1. Main cause: Incorrect cleaning or other surface preparation. If sanding dust or other contaminants are not completely removed, the topcoat cannot adhere properly to the primer, resulting in poor adhesion.
2. Incompatibility between the primer and topcoat, or between the primer and the substrate.
3. The topcoat is applied before the primer has dried.
4. Insufficient sanding or no sanding at all makes the surface too smooth.
5. Low-quality thinner with poor solvent action.
6. The topcoat is applied before the first layer has dried, when painting with multiple colors.
7. When painting with metallic paint: insufficient flash-off time between layers or too high viscosity.
8. Too long a delay between applying the primer and the topcoat.
9. An invisible water film is present on the primer surface before applying the topcoat:
   • The weather is too humid during primer application.
   • The primer surface is left to dry too long in damp night conditions.

Solution

1. Remove the existing paint by sanding and repaint the surface.

Recommended products to prevent and correct possible issues:

• Abrasives and accessories

• Paint spray guns

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