Coal Tar Sealer Vs Asphalt Emulsion: A Comparison Of Driveway And Pavement Sealers

Coal Tar Sealer Vs Asphalt Emulsion: A Comparison Of Driveway And Pavement Sealers

Coal Tar and Asphalt Emulsion are two types of sealers used in asphalt sealcoating operations, and while they may appear similar, they have significant differences.

Coal Tar Sealer: Coal Tar is a syrupy, black liquid derived from coal and the by-product steel-making process. It is the most commonly used sealer in the industry due to its availability and economical nature as it can be diluted with water and mixed with other mineral ingredients. Coal tar is known for its durability, wear-resistance, and ability to withstand heavy traffic without cracking or wearing away. It is also resistant to oil spills, gasoline spills, water penetration, and ultraviolet rays from the sun.

It produces a deep dark color, which is aesthetically pleasing. However, coal tar contains high levels of polycyclic aromatic hydrocarbons (PAHs), which can be dangerous if ingested or inhaled in large amounts over long periods of time. It also does not adhere as well as other types of sealants such as asphalt emulsion because it is thicker and harder to spread evenly across the pavement surface.

Asphalt Emulsion Sealer: Asphalt Emulsion uses asphalt cement along with minerals, polymers, and other ingredients that increase its durability. It has a significantly higher solid content than Coal Tar, giving it a longer life. Asphalt Emulsion is made from the same asphalt base material, which allows it to expand and contract based on weather and temperature, unlike Coal Tar.

It dries darker than coal tar sealer, producing a pitch-black color. However, it requires more frequent applications and specific conditions for optimal results. It is also less odorous and considered safer for the environment.

Table of comparison:

Feature	Coal Tar Sealer	Asphalt Emulsion Sealer
Composition	Derived from coal and the steel-making process.	Consists of asphalt cement, minerals, polymers, and other ingredients.
Common Use	Widely used due to availability and economic nature.	Increasing popularity due to environmental considerations.
Dilution	Can be diluted with water and mixed with minerals.	Typically comes pre-mixed and ready to use.
Durability	Known for durability, wear-resistance, and withstanding heavy traffic.	Higher solid content, providing longer life.
Resistance	Resistant to oil spills, gasoline spills, water penetration, and UV rays.	Offers resistance to various weather conditions.
Color	Produces a deep dark color, aesthetically pleasing.	Dries darker than coal tar, producing a pitch-black color.
Health Concerns	Contains high levels of PAHs, with potential health risks over long exposure.	Generally considered less hazardous to health.
Adhesion	Does not adhere as well as asphalt emulsion due to thickness.	Adheres well and spreads more evenly across the pavement surface.
Expansion and Contraction	Does not expand and contract as well as asphalt emulsion.	Expands and contracts based on weather and temperature.
Frequency of Applications	Generally requires fewer applications.	Requires more frequent applications for optimal results.
Environmental Considerations	Considered less environmentally friendly due to health concerns.	Considered safer for the environment, less odorous.
Odor	Can have a strong odor during application.	Generally less odorous compared to coal tar.

Key Takeaways:

• Coal tar sealer and asphalt emulsion are two popular options for sealing asphalt pavement.
• Environmental concerns and a shortage of raw materials have led to the increasing use of asphalt emulsion.
• Asphalt emulsion offers advantages such as local sourcing, lower environmental impact, and a rich, black color when dry.
• Disadvantages of asphalt emulsion include the need for more frequent applications and temperature sensitivity.
• Proper application techniques and following manufacturer’s instructions can mitigate the drawbacks of asphalt emulsion.

The Pros of Asphalt Emulsion

Asphalt emulsion offers several advantages over coal tar sealer. Firstly, the raw materials for asphalt emulsion production are locally sourced, reducing the reliance on imported materials and potential supply chain issues. This not only supports local economies but also reduces transportation emissions.

Additionally, asphalt emulsion is considered to be more environmentally friendly. While both products contain compounds that can be harmful, asphalt emulsion has lower toxicity levels, posing less risk to aquatic life, wildlife, and human health compared to coal tar sealer. This is an important factor in promoting sustainable asphalt maintenance practices.

Another advantage of using asphalt emulsion is its aesthetic appeal. When applied, it dries to a rich, black color, enhancing the overall appearance of the pavement. In contrast, coal tar sealer tends to dry to a gray color, which may not be as visually appealing. The deep black color of asphalt emulsion provides a crisp and clean look to driveways and pavements, improving the overall curb appeal of properties.

It’s important to note that asphalt emulsion may require more frequent applications compared to coal tar sealer. The lower solid content of asphalt emulsion and the need for additives to match the durability of coal tar sealer can result in a shorter lifespan. However, this can be mitigated by using additives specifically designed to enhance the longevity of asphalt emulsion sealers.

Advantages of Asphalt Emulsion	Disadvantages of Asphalt Emulsion
Locally sourced raw materials Reduced reliance on imported materials Lower environmental impact Enhanced aesthetic appeal	May require more frequent applications Temperature-sensitive application

The Cons of Asphalt Emulsion

While asphalt emulsion has many advantages, it is essential to consider its drawbacks in order to make an informed decision for your asphalt maintenance needs. One notable disadvantage of asphalt emulsion is its frequency of application. Compared to coal tar sealer, asphalt emulsion may require more frequent applications to ensure optimal protection. This is due to its lower solid content and the need for additives to match the durability of coal tar sealer.

Another factor to consider is the temperature requirements for applying asphalt emulsion. It is crucial to apply asphalt emulsion when temperatures are 55°F and above. This means that the application season for asphalt emulsion may be shorter compared to coal tar sealer, which is more forgiving in various weather conditions. However, by following proper application techniques and adhering to the manufacturer’s instructions, these temperature-related issues can be effectively managed.

It is important to inform customers that temporary tire and scuff marks may appear on the surface after the application of asphalt emulsion. Assure them that these marks will fade over time as the emulsion cures and dries. Additionally, proper storage of asphalt emulsion is vital to prevent pressure build-up and bacterial growth. It is also crucial to follow recommended safety measures during handling and application to ensure the well-being of both workers and the environment.

Despite these disadvantages, asphalt emulsion remains a popular alternative to coal tar sealer due to its environmental friendliness, locally-sourced raw materials, and aesthetic appeal. By carefully considering these cons and taking the necessary precautions, you can effectively utilize asphalt emulsion for your asphalt maintenance and protection needs.