> Resource Hub / Blog / Abrasive blasting: How to prep a surface for coating

Abrasive blasting: How to prep a surface for coating

Before applying a coating, the surface must be free of rust, scale, old coatings, and contaminants such as oil or grease. Poor surface preparation can lead to premature coating failure, adhesion issues, and costly rework. Abrasive blasting is widely used across industries such as aerospace, marine, and infrastructure to achieve the required surface profile and cleanliness standards.

1. Assess the surface condition

Before blasting begins, assess the condition of the surface. Identify contaminants, corrosion levels, and previous coatings. The extent of the surface condition will determine the abrasive material and blasting pressure required.

 

2. Choose the right abrasive media

Selecting the correct abrasive media is essential for achieving the desired finish. Common types include:

• Garnet: A versatile, low-dust option with excellent cutting power.
• Aluminium oxide: Ideal for aggressive blasting on hard surfaces.
• Glass beads: Used for cleaning and finishing without excessive material removal.
• Steel shot: Suitable for heavy-duty applications and rust removal.

You can see Airblast Eurospray’s full range of abrasive media here. For prices, guidance on selecting the right media, or to place an order, please call us on 01778 560650.

 

3. Select the appropriate blasting method

Different blasting techniques suit different applications:

• Abrasive blasting: Uses high-pressure abrasive materials to clean or profile surfaces.
• Dry blasting: Effective for rust and coating removal but generates dust.
• Wet blasting: Reduces dust and heat, ideal for sensitive environments.
• Direct abrasion: Uses sanders, grinders, and wire brushes to remove coatings or imperfections, suitable for small areas. Generates dust, so recovery systems are beneficial.
• Ultra-high-pressure (UHP) water jetting: High-pressure water removes coatings and contaminants without damaging surfaces. Eco-friendly with minimal water use, suitable for marine, energy, and industrial applications.
• Shot blasting machines: Propel steel shot using centrifugal force to clean and strengthen surfaces, ideal for large areas and repeated components.

4. Ensure proper equipment setup

Check that all blasting equipment is in optimal working condition. This includes:

• Blast nozzle size and type.
• Air pressure settings.
• Abrasive feed rate.
• PPE for operator safety (blast suits, gloves, helmets, and respiratory protection. You can see Airblast Eurospray’s full range of PPE here).
• Blast rooms and booths.

 

5. Conduct the blasting process

Execute the blasting process using consistent technique:

• Maintain the correct nozzle distance and angle.
• Use overlapping strokes to achieve even coverage.
• Monitor surface roughness to match the specified coating requirements.

 

6. Clean and inspect the surface

After blasting, remove residual dust and loose abrasives using compressed air or vacuum systems. Inspect the surface for:

• Uniform texture and profile
• Complete removal of rust, scale, and contaminants
• Compliance with the specified cleanliness standard (e.g., BS EN ISO 8501-1)

 

7. Apply coating immediately

To prevent flash rusting, apply primers or coatings as soon as possible after blasting. A delay in coating application can result in surface contamination, requiring additional preparation.

Abrasive blasting is a powerful and efficient way to prepare surfaces for coatings, ensuring strong adhesion and long-term performance. By following best practices – choosing the right media, method, and equipment – you can achieve a high-quality finish while minimising material waste and operational downtime.

For further guidance on abrasive blasting equipment and techniques, you can contact us on 01778 560650, or email enquiries@airblast.co.uk.