Having trouble deciding how to finish your wood? To help you choose the right product for your next project, we asked professionals to clarify the differences.
Woodwork is protected and made more beautiful with a finish coat. In the right hands, it can make an excellent woodwork project look shoddy, while in the wrong hands, it can make the project look shoddy. Therefore, it’s important to choose the right finish for your project.
Despite the variety of finishes available, even experienced DIYers can be overwhelmed by the number of options available. It’s a good thing we’re here to help!
What are the key differences between polyurethanes, lacquers, and varnishes, and what products do woodworkers and painters recommend for DIY projects?
What Is Polyurethane Wood Finish?
In that case, you are absolutely right in thinking “polyurethane” is a type of plastic. After application, polyurethane (also known as poly) hardens into a solid. In addition to stain/poly combos, it comes in a variety of sheens.
Lacquers and varnishes provide a thinner layer of finish than poly. Anthony Lara’s 30 years of experience as president and owner of Picazzo Painting have taught him to appreciate polyurethane’s durability.
This might be your hero if you live in a busy household or have a lot of traffic in your home, Lara says. If it gets damaged, he says, “repairing that thick, plastic-like layer isn’t a walk in the park.” Luckily, the initial application is forgiving, making it a popular choice for beginners.
It’s important to understand the product you’re using, says Nick O’Keefe of Oak City Coatings. Manufacturers tell him many DIYers and professionals fail to follow directions. Despite the best intentions, improper prep and application methods can lead to failure.
Polymer specifics:
-
Suitable for high-traffic areas that might be subjected to abuse.
-
High durability.
-
The drying time is medium (two to four hours).
-
Application ease: Easy.
-
Methods of application: Brush, wipe on, spray.
-
Low cost ($10 to $25 per quart).
-
Water-based, low-odor, easy to clean. VOCs are higher in oil-based products.
What Is Lacquer?
Unlike polyurethane and varnish, this clear, fast-drying finish does not require sanding between coats. Additives in lacquer dissolve the previous layer, allowing the new coat to blend into it. A single, solid surface is created as a result.
According to Lara, lacquer enhances the grain patterns of wood, bringing out its natural beauty. You can choose a high-gloss finish or a mellow matte finish.”
The smooth and polished appearance of lacquer appeals to industry veteran Phi Dang, owner of Newline Painting. Although the thinner layers make it more susceptible to scratches, he says, it may not offer the durability needed for a high-traffic area.
Spray-on lacquers are popular among DIYers due to their ease of application and quick drying time. Moreover, the speedy drying makes it suitable for areas with dust or pollen. If you can keep the air clean for half an hour, you should be fine.
-
Best uses: Detailed woodwork and fine furniture.
-
Durability: Long-lasting.
-
Dry time: Fast (around 30 minutes, with some drier in five minutes).
-
Ease of application: Spray application is easier than brush application.
-
Application methods: Spraying or brushing
-
Cost: Medium (20 cents per quart).
-
Safety and sustainability: VOCs are high in lacquer. Wear a respirator with vapor-rated filters.
What Is Varnish?
For outdoor furniture, our expert panel unanimously recommended varnish. In addition to its UV protection, Dang noted that it is a favorite for outdoor wood furniture and decks.
According to Lara, DIYers should know varnish takes time to dry. Rushing the process can cause “peeling, cracking, or even bubbles to form.”
-
Best uses: Items exposed to heat and humidity, such as outdoor furniture.
-
Durability: High outside (especially spar varnish), low indoor.
-
Dry time: Long (four to twenty-four hours between coats).
-
Application ease: Medium. Multiple coats are required, but it is relatively easy to apply.
-
Methods of application: Brush or spray. In most cases, conversion varnish is sprayed, while other types are brushed on.
-
Cost: Expensive ($25 to $40 per quart).
-
Safety and sustainability: Varnish is generally lower in VOCs and environmental impact than polymers or lacquers.
Polyurethane vs Lacquer
Adhesion type and dry time are the two main differences.
-
Adhesion: Poly finishes adhere to wood surfaces and each other. The lacquers meld with the lower layers, first by penetrating the wood, then by melting and bonding with the previous lacquer coats. With lacquer finishes, you can skip sanding between coats, which is why poly must be sanded between coats.
-
Dry time: Oil-based poly takes up to a day to dry, while water-based poly takes hours. It usually takes less than a half hour for lacquers to dry.
Both finishes are versatile. For figurines, jewelry boxes, and other items that will often be touched, lacquers are an excellent choice. It works on floors, shelving, and items that are frequently walked on or used.
Varnish vs. Polyurethane
What is the main difference? Varnish is more resistant to water and sunlight. In addition, it’s more flexible, expanding and contracting as the temperature changes. The characteristics of varnish make it a popular choice for outdoor furniture.
The outdoor protection comes from varnish, while the heavy duty protection comes from polyurethane, says Lara.
‘Spar’ varnishes or urethanes are recommended for applications with intense outdoor exposure. The term spar refers to boat-building finishes that are highly resistant to water, sun, and temperature. Because nautical wood is expected to be refinished regularly, they’re less resistant to scuffs and scratches.
