18th March 2025
When it comes to achieving a flawless finish, preparation is everything, and shot blasting shot plays a critical role. The choice of abrasive media, whether it’s grit or round shot, directly impacts surface quality, coating adhesion, and long-term durability. This blog dives into the world of shot blasting, exploring the different types of abrasives, their applications, and why selecting the right medium is crucial for ensuring a top-quality finish. Whether you’re new to the process or looking to refine your understanding, this guide will help you make informed decisions for your projects.
Table of Contents
What Is Shot Blasting?
Shot blasting is an essential process in metal surface preparation. It involves propelling abrasive media, commonly referred to as “shot,” at high velocity to clean, smooth, or roughen a surface. This process removes rust, mill scale, and other contaminants, ensuring that subsequent coatings, such as primers or powder coatings, adhere perfectly.
For companies like NSP Coatings, shot blasting isn’t optional—it’s the first step in achieving a flawless finish. The quality of the abrasive medium used can make or break the final result.
The Role of Abrasives in Shot Blasting
The abrasive medium is the star of the shot blasting process. The choice of material determines the efficiency of cleaning, the surface texture, and the adhesion quality of coatings. Not all abrasives are created equal, which is why it’s important to understand their properties and applications.
Types of Abrasive Media for Shot Blasting
Grit vs. Shot: What’s the Difference?
The terms “grit” and “shot” are often used interchangeably, but they refer to different shapes of abrasive media:
- Grit: Angular and sharp, ideal for removing rust, mill scale, and tough coatings. It creates a rough profile that promotes coating adhesion.
- Shot: Spherical in shape, providing a smoother finish but less aggressive cleaning. It’s often used for peening or strengthening metal surfaces.
At NSP Coatings, we exclusively use shot blasting grit to ensure a robust, textured surface that’s perfect for applying protective coatings like powder coating.
Sandblasting: The Classic Method
Sandblasting, once a popular technique, involves blasting sand particles onto a surface. While effective, sand has largely fallen out of favour due to health risks from silica dust exposure. Alternatives like steel grit and glass beads are now preferred.
- Steel Grit: Angular particles that are highly effective in cleaning and preparing metal surfaces. It’s a go-to choice for heavy-duty applications where aggressive cleaning is required.
- Steel Shot: Round and smooth, used mainly for polishing or creating a less abrasive surface profile. It’s less effective for applications requiring deep cleaning.
Aluminium Oxide and Glass Beads
- Aluminium Oxide: A versatile abrasive suitable for hard surfaces. It’s reusable and works well for precision applications.
- Glass Beads: Spherical and gentle, often used for polishing or finishing delicate surfaces.
Why the Medium Matters in Surface Preparation
The type of abrasive medium used in shot blasting affects:
- Surface Profile: Angular grit creates a textured profile for superior coating adhesion, while round shot offers a smoother surface.
- Speed: Grit tends to work faster due to its aggressive nature, reducing preparation time.
- Durability: Steel grit is long-lasting and can be recycled multiple times, making it cost-effective for large-scale operations.
The Advantages of Using Shot Blasting Grit
At NSP Coatings, we prefer shot blasting grit over round shot for the following reasons:
- Superior Adhesion: The angular texture left by grit ensures that coatings like primers and powder coatings bond effectively.
- Efficient Cleaning: Grit removes stubborn contaminants quickly, leaving the surface spotless.
- Consistency: The even texture created by grit ensures a uniform finish, reducing the risk of coating failure.
NSP Coatings: Experts in Shot Blasting and Powder Coating
As one of the leading powder coaters Kent, NSP Coatings understands the importance of shot blasting in delivering top-tier results. Every item that passes through our facility is shot blasted using high-quality grit to achieve the perfect substrate for subsequent coatings.
Whether it’s hot zinc spray, primers, or decorative powder coating, our process ensures durability and aesthetic appeal. And with our state-of-the-art equipment, we can handle even the most challenging structural and architectural steel projects.
Conclusion
Shot blasting is more than just surface preparation—it’s a crucial step that sets the stage for lasting and flawless finishes. By choosing the right abrasive medium, like shot blasting grit, you ensure superior adhesion, efficient cleaning, and consistent results. While sandblasting and steel shot have their uses, the angular grit we use at NSP Coatings in our shot blast room delivers unparalleled performance.
Looking for industrial coating services that include shot blasting and a smooth, durable finish? NSP Coatings is here to help. From powder coating to hot zinc spray, our tailored solutions ensure your projects meet the highest standards.
Get in touch today to learn more about our services and let us show you why we’re the trusted name in powder coaters Kent.
