For pipelines transporting gas, oil, water, or other fluids, improper surface preparation can lead to leaks, structural failures, and unexpected operational shutdowns, resulting in financial losses and environmental risks. In the case of equipment exposed to cavitation, erosion, and friction, a poorly adhered coating may not withstand mechanical and chemical stresses, compromising equipment integrity and requiring frequent maintenance.

Main Contaminants and How to Remove Them

The adhesion of the coating depends directly on the removal of contaminants from the metallic surface. Below are the most common contaminants and the appropriate methods for their elimination:

1. Oils and Greases

• Source: Industrial lubricants, operational fluids, and manufacturing residues.

• Impact: Prevents the coating from adhering by creating a barrier between the surface and the applied material.

• Solution: Removal with suitable degreasing solvents (ISO 8502-3) and cleaning with clean, dry cloths before blasting.

2. Moisture and Condensation

• Source: Humid environments, cold pipelines, and abrupt temperature changes.

• Impact: Reduces adhesion and can cause bubbles in the coating.

• Solution: Slightly heat the surface, check ambient temperature and dew point (ISO 8502-4), and ensure the surface is at least 3°C above the dew point before applying the coating.

3. Rust and Oxides

• Source: Exposure to oxygen and moisture over time.

• Impact: Reduces the mechanical strength of the coating and can continue corroding the metal under the applied layer.

• Solution: Use abrasive blasting (ISO 8501-1 Sa 2.5) or mechanical brushing (SSPC-SP3) in hard-to-reach areas.

4. Dust and Abrasive Residues

• Source: The blasting and sanding process.

• Impact: Small particles can create weak points in the coating's adhesion.

• Solution: Removal with dry and filtered compressed air or anti-static cloths per ISO 8502-3.

5. Soluble Salts (Chlorides and Sulfates)

• Source: Exposure to marine environments, chemicals, or corrosive fluids.

• Impact: May cause corrosion under the coating and reduce its durability.

• Solution: Wash with pressurized fresh water and conduct contamination tests using ISO 8502-9 before coating application.

Key Technical Standards for Coating Applications

To ensure quality and durability, industrial coatings must be applied according to internationally recognized standards. Below are some of the most important ones:

✅ ISO 8501-1 – Standards for cleaning metallic surfaces before coating application.

✅ ISO 8502-3 – Procedures to check for contaminants such as dust and oils.

✅ ISO 8503-1 – Determination of ideal roughness for optimal coating adhesion.

✅ ISO 8502-4 – Measurement of the dew point to prevent condensation before application.

✅ SSPC-SP10 / NACE 2 – Specifications for high-efficiency abrasive blasting.

✅ ASTM D4541 – Adhesion testing of the coating after curing.

✅ ISO 2808 – Methods for measuring the thickness of the applied coating.

Following these standards ensures that the coating application is efficient and durable, preventing premature failures and extending the service life of pipelines and equipment.

Best Practices for High-Performance Coating Application

1 Choosing the right coating – Use epoxy resins, polyurethane, or ceramic coatings according to the application needs.

2 Mechanical surface preparation – Use abrasive blasting to remove impurities and create the proper anchoring profile.

3 Monitoring environmental conditions – Ensure temperature and humidity remain within recommended parameters.

4 Controlling coating thickness – Apply uniform layers and measure with ultrasound (ISO 2808).

5 Adhesion and resistance testing – Conduct tests such as the pull-off test (ASTM D4541) to ensure proper bonding.

6 Final inspection and application validation – Evaluate full coating coverage before releasing equipment for operation.

Conclusion

Improper surface preparation can compromise the effectiveness, durability, and mechanical resistance of industrial coatings, leading to premature failures, leaks, and high maintenance costs. Following best practices and technical standards is essential for an efficient and long-lasting application.

Although often overlooked, surface preparation protocols are one of the key success factors in sealing leaks or restoring surfaces.

By focusing on preparation, contaminant control, and standardized techniques, industries can increase the reliability of their equipment and pipelines, reduce operational costs, and prevent structural failures, keeping their assets fully operational for much longer.