Surface Preparation for Pipe Coatings

The best coating fails on a poor surface.

Steps

1. Remove oil and grease
2. Abrasive blast to the specified cleanliness and profile
3. Remove dust
4. Prime promptly before rust forms

Checks

• Surface cleanliness standard
• Profile depth
• Dew point and surface temperature

Typical steps and standards

Environmental conditions

Surface temperature should be at least 3 °C above dew point to prevent condensation. Check humidity before blasting and coating.

Common defects from poor preparation

• Blistering and disbondment
• Rust spots under coating
• Poor holiday test results

Good preparation is often the single biggest factor in coating life.

See pipe coating grade gilsonite.