Yesterday, 04:09 PM
The Challenge: Applying Emulsion at Precise Rates
In mill-and-overlay projects involving paving fabric, precision in applying asphalt emulsion is critical. For example, when installing glass-reinforced paving fabric over 108,000 square yards, the distributor must spray PG 58-28 oil at exactly 0.13 gallons per square yard. This ensures proper adhesion without oversaturation, which could compromise the pavement structure or create a slippery, unsafe surface.
While experienced distributor drivers make this look easy, the task demands calibration, equipment familiarity, and attention to detail—especially when transitioning from subcontracted professionals to in-house crews.
Understanding Distributor Truck Systems
Modern distributor trucks are equipped with computerized controls that allow operators to input desired spray rates, monitor tank levels, and adjust bar widths. Older models, however, rely on mechanical shot charts and manual calibration.
Key components include:
On a scale of 1 to 10:
A contractor in Wyoming decided to self-perform the emulsion spraying to save $6,000. While they had the equipment and drivers, their team lacked experience in precision spraying. The challenge was to apply 55 tons of oil for the fabric—not the full 400 tons allocated for the leveling course. Misapplication could result in nearly 1.0 gallon per square yard—turning the road into a swimming pool of asphalt.
With guidance from experienced operators, they learned to calibrate the truck, verify nozzle settings, and monitor spray rates in real time. The result was a successful application and a valuable skill added to their crew’s capabilities.
Daily Maintenance and Pump Priming Tips
Operators of newer distributor models like the Rosco Maximizer 2 have reported issues with pump startup after overnight shutdowns. Unlike older Etnyer models, which respond quickly to diesel priming, newer systems may strain or whine before engaging.
Recommended solutions:
Operating an asphalt distributor truck may seem straightforward, but precision spraying requires calibration, consistency, and care. Whether using a modern Maximizer or a vintage Etnyer, the key is understanding your equipment and maintaining it properly. With the right training and attention to detail, even first-time crews can achieve professional results—saving money and building confidence in their capabilities.
In mill-and-overlay projects involving paving fabric, precision in applying asphalt emulsion is critical. For example, when installing glass-reinforced paving fabric over 108,000 square yards, the distributor must spray PG 58-28 oil at exactly 0.13 gallons per square yard. This ensures proper adhesion without oversaturation, which could compromise the pavement structure or create a slippery, unsafe surface.
While experienced distributor drivers make this look easy, the task demands calibration, equipment familiarity, and attention to detail—especially when transitioning from subcontracted professionals to in-house crews.
Understanding Distributor Truck Systems
Modern distributor trucks are equipped with computerized controls that allow operators to input desired spray rates, monitor tank levels, and adjust bar widths. Older models, however, rely on mechanical shot charts and manual calibration.
Key components include:
- Spray bar: Adjustable in width and height, controls distribution pattern
- Pump: Pressurizes and circulates emulsion through the system
- Nozzles: Determine spray angle and flow rate
- Control system: Ranges from manual levers to digital interfaces
- Calibration chart or software: Converts gallons per square yard into pump speed and truck speed
- PG 58-28: A performance-graded asphalt binder designed for specific temperature ranges
- Shot chart: A reference table used to manually set spray rates based on truck speed and nozzle configuration
- Maximizer 2: A model of distributor truck with advanced computerized controls
- Clean-out procedure: A daily maintenance routine using diesel to flush emulsion from the system
On a scale of 1 to 10:
- New computerized distributors: 2–3 (easy, assuming calibration is correct)
- Older mechanical distributors: 5–7 (requires experience and consistency)
- Uncalibrated or malfunctioning systems: 8–10 (high risk of error and mess)
A contractor in Wyoming decided to self-perform the emulsion spraying to save $6,000. While they had the equipment and drivers, their team lacked experience in precision spraying. The challenge was to apply 55 tons of oil for the fabric—not the full 400 tons allocated for the leveling course. Misapplication could result in nearly 1.0 gallon per square yard—turning the road into a swimming pool of asphalt.
With guidance from experienced operators, they learned to calibrate the truck, verify nozzle settings, and monitor spray rates in real time. The result was a successful application and a valuable skill added to their crew’s capabilities.
Daily Maintenance and Pump Priming Tips
Operators of newer distributor models like the Rosco Maximizer 2 have reported issues with pump startup after overnight shutdowns. Unlike older Etnyer models, which respond quickly to diesel priming, newer systems may strain or whine before engaging.
Recommended solutions:
- At shutdown, suck diesel through the spray bar to flush emulsion
- Pour a small amount of diesel into the intake cap and let it soak overnight
- Ensure nozzles are clean and free of hardened residue
- Check pump seals and pressure relief valves for wear
- Spray rate: 0.13 gal/SY for fabric, higher for leveling courses
- Pump pressure: Should match nozzle and bar configuration
- Truck speed: Must be consistent to maintain uniform application
- Temperature: Emulsion viscosity changes with ambient and binder temperature
- Nozzle spacing: Affects overlap and uniformity
- Calibrate the distributor before each project using test passes
- Train drivers on both manual and computerized systems
- Maintain a log of spray rates, temperatures, and nozzle settings
- Use GPS or onboard sensors to track coverage and avoid overlap
- Flush system daily with diesel to prevent clogging and pump strain
Operating an asphalt distributor truck may seem straightforward, but precision spraying requires calibration, consistency, and care. Whether using a modern Maximizer or a vintage Etnyer, the key is understanding your equipment and maintaining it properly. With the right training and attention to detail, even first-time crews can achieve professional results—saving money and building confidence in their capabilities.
