SATA & Anest Iwata Spray Gun Setup Guide
Correct spray gun setup is essential for consistent atomisation, material transfer and finish quality. This guide covers the fundamentals of setting up SATA and Anest Iwata spray guns for automotive primer, basecoat, clearcoat and direct-gloss applications.
Use this guide as a starting point and always check the paint manufacturer’s Technical Data Sheet and the spray gun manufacturer’s recommendations for the exact product and gun being used.
The Four Fundamentals of Spray Gun Setup
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Fluid Tip / Nozzle Size
The fluid tip controls how easily material can pass through the gun. Primers generally require a larger setup than basecoats and clearcoats because of their higher viscosity.
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Air Pressure
Air pressure affects atomisation and transfer efficiency. Too little pressure can produce coarse atomisation, while excessive pressure can increase overspray and material waste.
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Fan Pattern
The fan control changes the width and shape of the spray pattern. A correctly adjusted fan should provide an even distribution of material across the pattern.
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Material Flow
The fluid control determines how much coating is delivered when the trigger is fully pulled. It must be balanced with air pressure, nozzle setup and spraying speed.
SATA & Anest Iwata Spray Gun Technologies
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SATA: HVLP & RP
SATA offers two main automotive atomisation technologies. HVLP operates at lower pressure and is designed for high transfer efficiency, while RP (Reduced Pressure) operates at a somewhat higher pressure and is designed for faster application.
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Anest Iwata: Split Nozzle™
Anest Iwata’s current WS-400 and LS-400 Series 2.1 guns use Split Nozzle™ 2.0 pre-atomisation technology. The LS-400 is aimed primarily at basecoat application, while WS-400 variants are available specifically for basecoat and clearcoat applications.
Which Spray Gun for Which Job?
SATA’s dedicated automotive primer and filler gun. Suitable for 1K and 2K primers, fillers and wet-on-wet applications, with the nozzle setup selected to suit the product being sprayed.
A dedicated primer range with versions for filler, wet-on-wet and UV primer applications, allowing the gun to be matched to the specific primer process.
Recommended for efficient application of waterborne and solvent-based basecoats. Available with different spray-pattern options to suit painter preference and application style.
Purpose-built for solvent and waterborne basecoat application, with controlled atomisation and high transfer efficiency.
RP technology is well suited to clearcoat application where fast working speed, fine atomisation and a high-quality finish are required.
Iwata’s dedicated premium clearcoat gun, designed for controlled atomisation, material flow and finish quality.
Suitable for 1K and 2K topcoat systems and a strong choice for 2K direct-gloss application. Select the nozzle setup according to the coating manufacturer’s TDS.
A suitable premium finish-gun platform for 2K topcoat application when correctly matched to the coating. Select the nozzle and pressure according to the paint manufacturer’s TDS.
Understanding Nozzle Size & Air Pressure
The fluid nozzle, needle and air cap work together to control material delivery and atomisation. The correct nozzle setup depends on the viscosity and type of coating being sprayed.
Primer and filler products generally require larger fluid openings, while basecoats and clearcoats normally use smaller finishing setups. Air pressure must then be matched to the spray gun technology and nozzle configuration.
Recommended Nozzle Sizes & Air Pressure
These figures are manufacturer-backed starting points for the recommended SATA and Anest Iwata gun families. Always check the coating Technical Data Sheet because the exact product may require a different nozzle or setup.
Common filler-primer setups: 1.6–2.1 mm
Recommended dynamic inlet pressure: 2.0 bar / 29 psi
Available filler setups: 1.4, 1.6 or 1.8 mm
Recommended inlet pressure: 2.0 bar / 29 psi
Suitable starting setup for wet-on-wet primer: 1.4 mm
Recommended dynamic inlet pressure: 2.0 bar / 29 psi
Available setups: 1.2, 1.3 or 1.4 mm
Recommended inlet pressure: 2.0 bar / 29 psi
Common automotive choices: 1.2–1.4 mm
Recommended dynamic inlet pressure: 2.0 bar / 29 psi
Available setups include 1.2–1.5 ET / ETS configurations.
Recommended inlet pressure: 1.8 bar / 26 psi
Common automotive choices: 1.2–1.4 mm
Recommended dynamic inlet pressure: 2.0 bar / 29 psi
Available clearcoat setups include 1.2–1.5 HD configurations.
Recommended inlet pressure: 2.0 bar / 29 psi
Common starting setup: 1.3–1.4 mm
Recommended dynamic inlet pressure: 2.0 bar / 29 psi
Common recommended setup for 2K direct-gloss and topcoat applications: 1.3–1.4 HD
Recommended inlet pressure: 2.0 bar / 29 psi
Pressure figures are measured at the spray-gun inlet with the trigger pulled and air flowing. Always follow the coating manufacturer’s Technical Data Sheet or application chart where it specifies a different setup.
How to Set Up the Spray Gun
Nozzle size and air pressure are only part of the setup. Fan width, material flow and the final spray pattern should also be adjusted before applying paint to the vehicle.
Set the Air Pressure
Connect the gun to a clean, regulated air supply and set the recommended inlet pressure with the trigger fully pulled and air flowing through the gun.
Use the pressure specified for the gun and nozzle setup rather than relying on the compressor regulator alone.
Adjust the Fan Pattern
Open the fan control to produce a broad, even pattern suitable for the repair area. Full-panel work will normally use a wider fan, while smaller repairs may require the fan to be reduced.
Avoid reducing the fan excessively, as this changes how the material is concentrated within the spray pattern.
Set the Material Flow
Adjust the fluid control so the gun delivers enough material for the coating and application speed without overloading the panel.
For normal full-size refinishing work, the gun should be allowed to deliver a consistent supply of material rather than being excessively restricted at the fluid control.
Check the Spray Pattern
Make a test spray onto a suitable test surface before painting the vehicle. The pattern should be even from top to bottom with consistent atomisation and material distribution.
An uneven, heavy or distorted pattern can indicate incorrect adjustment, contamination, a blocked air cap or nozzle, or worn spray-gun components.
Understanding the Spray Pattern
As material leaves the fluid nozzle, compressed air from the air cap breaks it into fine droplets and shapes them into the spray fan. Correct atomisation helps produce even material distribution and a consistent finish across the panel.
Before spraying the vehicle, make a test pattern using the actual coating and final gun settings. The pattern can quickly reveal problems with pressure, material flow, adjustment or gun condition.
How to Read a Spray Pattern
A correct spray pattern should be even and balanced from top to bottom. Irregularities in the fan can help identify setup, contamination or component problems.
The fan should be balanced, with consistent atomisation and no obvious heavy or dry areas. This indicates the gun is generally set up correctly.
This can indicate contamination or blockage in the air cap, damaged air-cap holes or a problem with the nozzle or needle.
Check fan adjustment, air pressure and material flow. Excessive fluid delivery or an unsuitable setup can cause the centre of the pattern to become too wet.
This can occur when the fan is opened too far for the available material flow or when air pressure is too high for the current setup.
Check inlet pressure, material viscosity and nozzle choice. Low pressure or material that is too thick can reduce atomisation quality.
Clean and inspect the air cap and nozzle carefully. Dried paint, contamination or worn components can distort the pattern even when the pressure and controls are set correctly.
Spray Distance, Gun Movement & Overlap
Good gun setup still depends on consistent technique. Keep the spray gun square to the panel, maintain a steady distance and overlap each pass evenly to produce a uniform film.
Keep the air cap square and perpendicular to the panel.
Manufacturer recommended spraying distance.
Manufacturer recommended spraying distance.
Reference spray distance used for published fan-width specifications.
Keep the Gun Parallel
Move the whole gun across the panel while keeping it at approximately the same distance from the surface. Avoid pivoting from the wrist, as this moves the gun farther away at each end of the pass and can create uneven material build.
Maintain a Steady Speed
Travel speed and material flow work together. Moving too slowly can overload the surface and cause runs, while moving too quickly can produce poor coverage, dry spray or insufficient film build.
Overlap Each Pass Evenly
Use consistent overlap from one pass to the next. Around half to two-thirds of the previous spray pass is a useful general starting point, although the exact technique should follow the coating manufacturer's application instructions.
Trigger at the Right Time
Begin moving the gun before applying full material and release the trigger as the pass is completed. This helps prevent excess material building up at the beginning and end of each pass.
Cleaning & Maintaining Your Spray Gun
A correctly adjusted gun cannot produce a consistent spray pattern if the air cap, nozzle or fluid passages are contaminated or damaged. Clean the gun after use and inspect the main spraying components regularly.
Always follow the cleaning and maintenance instructions supplied by SATA or Anest Iwata for the exact spray gun being used.
Remove remaining coating and flush the fluid passages with a suitable cleaning product before material is allowed to dry inside the gun.
Keep the air-cap holes completely clear. Use appropriate cleaning brushes and tools and avoid damaging or enlarging the precision air openings.
Check for dried material, wear or physical damage. A damaged nozzle, needle or air cap can cause leakage, poor atomisation and an uneven spray pattern.
Refit components correctly and tighten them only as specified by the gun manufacturer. Precision parts can be damaged by excessive force.
Make sure the controls operate smoothly, connections are secure and the gun produces a clean, balanced test pattern before spraying the vehicle.
Before You Start Spraying
Run through these checks before applying material to the vehicle. A few seconds spent checking the setup can prevent avoidable finish problems.
Confirm the gun and nozzle setup suit the coating being applied.
Check the paint, hardener and thinner or reducer have been mixed to the correct ratio.
Strain the mixed coating before filling the spray gun to help prevent contamination and blockages.
Check the airline, filtration and regulator are providing clean, dry and stable compressed air.
Set inlet pressure with the trigger fully pulled and air flowing through the gun.
Adjust the fan width and material flow for the coating and repair area.
Confirm the spray pattern is even, balanced and correctly atomised before spraying the repair.
Make sure the surface is correctly prepared, clean, dry and free from dust or contamination.
Common Spray Gun Problems & Quick Checks
If the finish or spray pattern does not look right, check the gun setup before changing the paint system. Pressure, viscosity, contamination and worn components can all affect atomisation and material delivery.
Possible causes: Low inlet pressure, material too viscous, unsuitable nozzle setup or restricted airflow.
Check first: Dynamic pressure, paint viscosity, nozzle size and air-cap cleanliness.
Possible causes: Gun held too far from the panel, excessive air pressure, moving too quickly or unsuitable reducer speed.
Check first: Spray distance, pressure, travel speed and the coating TDS.
Possible causes: Excessive fluid delivery, moving too slowly, spraying too close or applying coats too heavily.
Check first: Material flow, gun speed, distance and application technique.
Possible causes: Blocked air-cap holes, contamination around the nozzle or damaged precision components.
Check first: Clean and inspect the air cap, fluid nozzle and needle before altering the gun settings.
Possible causes: Loose fluid-nozzle components, air entering the material passage, insufficient material or contamination.
Check first: Cup level, connections, fluid nozzle seating and material passages.
Possible causes: Excessive pressure, spraying too far from the panel or a setup that is poorly matched to the coating.
Check first: Dynamic inlet pressure, spray distance and the recommended gun/nozzle setup.
Need Help Choosing the Right Spray Gun?
If you’re unsure which SATA or Anest Iwata spray gun, nozzle setup or air-cap configuration is right for your paint system, our team can help you choose a suitable setup for the job.
