Abrasive air blasting might look simple—just point the nozzle and go—but without proper technique, it’s easy to make mistakes that waste time, materials, and reduce coating performance. Whether you're new to blasting or need a quick refresher, here are some of the most common errors and how to avoid them.

1. Using the Wrong Nozzle Angle

Angle is often overlooked, with many operators simply pointing the nozzle head-on. In reality, an angle of roughly 50 to 70 degrees from the surface typically yields the best combination of cleaning power and proper surface profile. Shallower angles can help reduce the risk of over-profiling thinner metals, while steeper angles cut away heavier contaminants. If the part has complex edges or corners, adjust accordingly to avoid “shadow” spots. It also reduces the risk of abrasive impingement on the surface.

2. Overloading the Abrasive Flow

Opening the valve wide might seem to speed things up, but it can create too much flow, slowing abrasive velocity and wasting material. A good starting point is about two full turns of the valve, then fine-tune by periodically measuring how much abrasive you’re using over a set time. Watch for any drop in air pressure or velocity. Keeping a consistent flow rate ensures both efficient cleaning and minimal media waste.

3. Ignoring Nozzle Wear

Nozzles endure constant abrasive impact. Over time, their orifice widens or becomes brittle, which can reduce blasting speed and produce inconsistent patterns. Check nozzle diameter or use a nozzle gauge regularly. Replace if you notice cracks, changes in shape, or if its opening surpasses the manufacturer’s wear limit. Small increments of wear can quickly increase air and abrasive consumption, so proactive checks pay off.

4. Incorrect Standoff Distance

Operators sometimes hold the nozzle too close—risking surface damage or embedding abrasive—or too far, creating weaker impact and higher media use. Generally, a distance of about 6 to 12 inches (15–30 cm) works well. Tailor this range to your specific substrate and project specifications: softer metals might need a bit more distance to avoid excessive roughening.

5. Poor Dust Control and Visibility

Dust control can be overlooked, but it’s crucial for operator safety, surface quality, and an efficient workflow. Excessive dust clouds obscure vision and can re-contaminate the blasted surface. Proper ventilation or well-designed dust collection systems help maintain visibility while protecting workers from hazardous particulates.

Final Check: Did You Meet Spec?

Once you refine angle, flow, nozzle condition, distance, and dust measures, take time to confirm the surface meets project requirements. A quick check of the surface profile or cleanliness helps ensure that your efforts translate into a truly optimized surface for coating.

By fine-tuning nozzle angle, abrasive flow, nozzle condition, standoff distance, and dust control, you’ll get better results with less waste. These simple improvements make a big difference in surface quality, coating performance, and equipment longevity.

Contact:chris.prouty@winoa.com

Contributing Editor for MFN and Technical Advisor at Winoa