Difference Between Spar Urethane And Polyurethane
Introduction
Spar urethane and polyurethane are two popular types of finishes used for woodworking projects. While both are effective in protecting surfaces, there are some key differences between spar urethane and polyurethane that make them better suited for different applications. This article will explore the differences between these two finishes, helping you make an informed decision when choosing the right one for your project.
What is Spar Urethane?
Spar urethane is a specific type of polyurethane that is designed to withstand harsh outdoor conditions. It contains added UV blockers and absorbers to protect against sunlight damage, making it suitable for use on wood surfaces that are exposed to sunlight, such as outdoor furniture, doors, and window frames.
One of the distinguishing features of spar urethane is its flexibility. It allows the wood’s natural expansion and contraction due to temperature and humidity changes without cracking or peeling. This flexibility makes spar urethane ideal for outdoor applications, as it can withstand the constant exposure to environmental elements.
What is Polyurethane?
Polyurethane, on the other hand, is a general-purpose finish suitable for both indoor and outdoor use. It offers excellent protection against water, chemicals, and general wear and tear, making it a popular choice for interior woodwork, such as cabinets, tabletops, and floors. However, unlike spar urethane, it is not specifically designed to withstand direct sunlight and outdoor elements.
Polyurethane forms a hard, clear coating that enhances the natural beauty of wood, giving it a glossy or satin finish depending on the desired look. It provides superior durability and resistance to scratches and impacts, making it suitable for high-traffic areas.
Application
When it comes to application, both spar urethane and polyurethane are available in various forms, including spray, brush-on, and wipe-on. They can be applied to the wood using a brush, a cloth, or a sprayer, depending on personal preference and the nature of the project.
However, spar urethane tends to be more viscous than polyurethane, making it a bit trickier to apply smoothly. It requires careful attention to avoid leaving brush marks or bubbles on the surface. On the other hand, polyurethane generally has a thinner consistency, allowing for easier application and a smoother finish.
Durability
When it comes to durability, both spar urethane and polyurethane provide excellent protection for wood surfaces. However, spar urethane tends to be more flexible, making it less prone to cracking or peeling over time. Its flexibility allows it to adapt to the wood’s movements caused by environmental factors, such as humidity or temperature changes.
Polyurethane, while still durable, may not fare as well in high-moisture or extreme temperature conditions. It may become brittle over time and show signs of wear and tear, especially in outdoor applications.
Cost
In terms of cost, polyurethane is generally more affordable compared to spar urethane. The additional UV blockers and added flexibility of spar urethane contribute to its higher price point. If you have a tight budget or are working on an indoor project that doesn’t require UV resistance, polyurethane may be the more cost-effective option.
Conclusion
In summary, spar urethane and polyurethane are two popular finishes that offer different advantages depending on the application. Spar urethane, with its added UV protection and flexibility, is an excellent choice for outdoor wood surfaces exposed to direct sunlight and harsh environmental conditions. Polyurethane, on the other hand, is a versatile option suitable for both indoor and outdoor use, offering superior durability and protection against water and general wear and tear.
Consider the specific needs of your project, such as the location, exposure to sunlight, and the overall usage, when deciding between spar urethane and polyurethane. Both finishes can greatly enhance and protect the beauty of your woodworking projects when chosen correctly.
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Difference Between Spar Urethane And Polyurethane
