Airport runways require durable and long-lasting paint that can withstand the heavy traffic and harsh conditions encountered on taxiways and runways. The paint used must provide high visibility markings that are easily seen by pilots and airport personnel in all weather and light conditions. In this article, we’ll examine the specialized paints used for airport runways and why they are well-suited for this demanding application.
Requirements for Runway Paint
The paint used on airport runways and taxiways has to meet stringent requirements not found in standard commercial and household paints. Here are some of the key requirements:
- Durability – Withstands jet blast, repeated landings, and all weather conditions
- Wear Resistance – Hardwearing and abrasion resistant
- Adhesion – Bonds tightly to concrete and asphalt surfaces
- Chemical Resistance – Withstands jet fuel, oil, grease, and deicing fluids
- Daytime Visibility – Provides high contrast markings easily visible in daylight
- Night Visibility – Retroreflective for visibility under aircraft landing lights
- Quick Drying – Minimum downtime for resurfacing active runways
- VOC Compliance – Meets regulations for low/no volatile organic compounds
Let’s look at some of the most common paint types used on airport runways and see how they meet these demanding requirements.
Epoxy Paint
Epoxy paints are two-component products consisting of an epoxy resin and a polyamine hardener. When mixed, these components react and cure to form a tough, cross-linked coating with excellent adhesion, durability, and chemical resistance.
Here are some key advantages of epoxy paints for airport runways:
- Excellent adhesion to concrete and asphalt
- Superior abrasion and wear resistance
- Withstands jet fuel, oil, grease, and harsh chemicals
- Long lasting durability on runway surfaces
- Can be formulated for low VOCs
While standard epoxy coatings provide an attractive glossy finish, they have low visibility under low light conditions. Therefore, glass beads are added to the paint to provide retroreflectivity for nighttime use. The beads refract and reflect landing lights back to the pilot’s eyes, making the markings clearly visible.
Polyurethane Paint
Polyurethane paints are made by reacting isocyanate resins with polyols to produce a tough, abrasion-resistant polymer coating. Some key advantages of polyurethane paint for airport runways are:
- High build protection for worn asphalt and concrete
- Excellent adhesion properties
- Abrasion and chemical resistant
- Can be formulated for quick drying
- Good flexibility and impact resistance
Polyurethane paints typically contain reflective glass beads to provide visibility at night. Highly durable aliphatic polyurethane is commonly used when maximum abrasion resistance, color stability, and longevity are required.
Methacrylate Paint
Methacrylate paints based on methyl methacrylate resin offer high durability and rapid curing ideal for airport markings. Benefits include:
- Ultra fast drying – Traffic ready in under an hour
- Excellent bonding to concrete and asphalt
- High abrasion and weathering resistance
- Low temperature application down to 35°F
- Good visibility with glass bead additives
The quick return to service is a major advantage for methacrylate paints on busy commercial runways where downtime needs to be minimized.
Comparison of Major Paint Types for Airports
Here is a comparison of the key paint types used for airport markings:
| Paint Type | Pros | Cons |
|---|---|---|
| Epoxy | Excellent durability and abrasion resistance | Requires longer drying time |
| Polyurethane | High build protection; good flexibility | Faster drying than epoxy but slower than methacrylate |
| Methacrylate | Extremely fast drying; high durability | Higher cost; strong odor during application |
Paint Application Process
Applying paint to airport runways involves more than simply rolling or spraying on a coat of paint. Here is a look at the key steps involved:
- Surface Preparation – Existing paint and contaminants are removed. The surface is cleaned and roughened to promote paint adhesion.
- Priming – A primer coat specific to the substrate (concrete or asphalt) is applied first to maximize adhesion.
- Paint Application – Paint is applied by specialized truck-mounted spray equipment for large surface areas. Rollers are used for edge work and smaller markings.
- Reflective Beads – Glass beads are immediately applied on top of the wet paint so they become embedded to provide retroreflectivity.
- Drying – Airport staff monitor the paint drying and restrict access until fully cured to prevent tracking.
- Marking Layout – Airport engineers follow FAA guidelines in designing and laying out runway markings.
It’s a complex, multi-step process requiring specialized equipment and trained personnel to consistently apply paint that will retain its markings, night visibility, friction characteristics, and durability over years of aircraft traffic.
Repainting Frequency
How often airport runways need to be repainted depends on factors such as:
- Aircraft traffic volume
- Weather and sun exposure
- Surface material (concrete vs. asphalt)
- Quality and type of paint used
On runways with very high traffic volume, paint may need to be renewed every 1-2 years. Under moderate traffic conditions, durability of 3-4 years can be expected. Airport maintenance staff periodically inspect markings and test friction to determine when repainting is required.
Safety Issues
Using the right paint on airport runways is critical for flight safety. Some key considerations include:
- Visibility – Markings must be clearly visible in all conditions to pilots.
- Braking Friction – Paint must provide adequate friction when aircraft brakes are applied upon landing.
- Jet Blast Resistance – Withstand powerful blast from jet engines for safety of ground personnel.
- Fuel Resistance – Prevent fuel deterioration of paint markings near gates.
Airport staff conduct periodic friction testing on runways to ensure paint meets minimum standards for safe braking performance. Rubber deposits can reduce braking action over time.
Environmental Considerations
Paints for airport runways need to meet environmental regulations, which poses challenges for their formulation. Areas of concern include:
- VOC limits – Limits on volatile organic compounds (VOCs) eliminate many conventional solvent paints.
- Heavy metal restrictions – Lead and chromate pigments provide durability but are hazardous.
- spill containment -special handling of paints is required to prevent discharge to storm drains.
Finding paints that meet durability specs while conforming to environmental rules requires specialized expertise. Despite these restrictions, major technical advances have produced runway paints that achieve the required performance while minimizing environmental impact.
Cost Considerations
Painting airport runways is an expensive process, with costs varying based on:
- Scale of project (partial remarking vs. complete repainting)
- Special access/safety requirements for working on active runways
- Surface preparation and extent of repairs needed
- Type of paint used
- Geographic location and local labor rates
For a major airport repainting an average runway, paint costs alone can easily exceed $100,000. When factoring in labor, equipment, closures/delays and other expenses, the total budget for a runway repainting project can run into the millions of dollars.
Conclusion
Painting airport runways requires specialized paints to provide high visibility under tough conditions. Epoxy, polyurethane, and methacrylate paints are common options, each with advantages depending on the application. Extensive surface preparation, precise application procedures, quick-drying capability and retroreflective beads are key considerations. Airport staff must balance durability, safety, visibility, and environmental compliance when selecting and maintaining paint for runways and taxiways. The right paint ensures pilots can operate safely while minimizing the need for frequent, costly repainting projects.
