Atomization FAQs – Polyurethane Coatings

Atomizing a coating means breaking the liquid paint into very fine droplets so it can be sprayed evenly onto a surface, resulting in a smooth and consistent finish.

The four main methods are:

• Air Spray (HVLP/LVLP/Conventional)
• Air-Assisted Airless (AAA)
• Airless Spray
• Electrostatic Spray

Each offers a different balance of finish quality, speed, and efficiency.

1. Air spray generally produces the finest atomization and smoothest finish, making it ideal for topcoats and decorative polyurethane applications.

Key factors include:

• Viscosity of the coating
• Spray tip size
• Pressure settings
• Solvent blend

Balancing these correctly is essential for achieving a high-quality finish.

Lower viscosity helps the coating break into finer droplets, improving flow and finish. This can be adjusted through temperature, mixing ratios, and the use of thinners within specification.

• Too much pressure can cause overspray, bounce-back, and dry spray
• Too little pressure can result in poor atomization, larger droplets, and uneven finishes

Correct pressure balance is critical.

Not necessarily.

At A&I Coatings, we’ve observed that some painters and equipment setups achieve an excellent finish with no thinners, while others may require up to 40% thinners to achieve the same result.

Thinners are used to help the coating apply smoothly to the surface and improve atomization.

They evaporate during curing, so the amount used can be adjusted depending on:

• Environmental conditions
• Applicator technique
• Equipment setup

There is no single “perfect” setup. Results can vary depending on:

• Spray equipment
• Operator technique
• Temperature and humidity

This is why flexibility in thinning is important to achieve consistent finishes.

It depends on your priorities:

• Smooth finish → Air spray
• Speed and efficiency → Airless or AAA
• Complex metal parts → Electrostatic
• High-build coatings → Airless

Selecting the right method ensures both performance and productivity.