Tung Oil Vs Polyurethane: Which is Better?

The wood finishing market is teeming with products, but two of the most popular options are polyurethane and Tung oil. They both offer unparalleled advantages that can significantly benefit your wood.

Nonetheless, Tung oil and poly are not the same, and understanding their differences can help you choose better for your projects.

Polyurethane dries to form a tough protective film on the wood surface, protecting it from moisture, scratches, and dents. In contrast, Tung oil gets absorbed into the wood, with some of it forming a thin film on the wood surface.

Since it blocks the wood pores, it offers some protection against moisture damage. Let’s dive in and see the comparison between Tung oil vs Polyurethane.

What is Tung Oil?

Tung oil is a clear, natural drying oil extracted from the Tung tree native to China and South America. It carries an amber tint to it, which helps enhance the color of wood while penetrating its pores and nourishing it.

Because Tung oil penetrates the pores in the wood, it fills them, making the wood resistant to moisture and water damage.

The oil is a drying type, so it also forms some film on the wood surface, but this layer is generally not solid enough to protect the wood from scratches and other forms of physical impact.

Like other drying oils, pure Tung oil reacts with oxygen to cure. This process can take as long as several days. For this reason, applying Tung oil to wood can be a long-drawn-out process because you need to apply about 5 to 7 coats of the oil for optimum protection. 

You must also reapply Tung oil at least every year to maintain the protection of your furniture or other wooden items.  If applied properly, Tung oil can emphasize the wood grain and bring out the character of your wood, making it look beautiful and polished.

Read also: How to remove tung oil finish from wood.

Pros

The oil allows the texture and character of the wood to show
It nourishes wood
The oil offers some protection against water and moisture damage
It enhances the wood grain

Cons

Is not waterproof
Tung oil must be reapplied every year to remain protective
It is unsuitable for outdoor applications

What is Polyurethane?

Polyurethane is a synthetic resin comprising urethane compounds, resins, solvents, and chemicals. While polyurethane is made by combining these ingredients in industrial processes, urethane compounds are their primary ingredient.

Poly is sometimes referred to as liquid plastic because urethanes are plastic-like substances that dry to form malleable, tough, and moisture-resistant materials.

Polyurethane can be water-based or oil-based. Both types are clear, with oil-based verities typically having a slightly yellowing tint. 

Because polyurethane forms a tough layer, it is typically used as a sealant. It can go onto bare wood or stained wood surfaces as a protective topcoat. 

Other than wood, polyurethane can adhere to metal, plastic, concrete, and a few other surfaces. This quality makes it versatile and widely useful. 

Polyurethanes are available in various sheen levels, including matte, satin, semi-gloss, and high gloss sheens. The material is tough and durable regardless of the sheen level, even though less glossy sheens tend to hide imperfections better.

Polyurethane is a popular wood finish for various reasons. Here are some of the main pros and cons of poly. 

Pros

Poly forms a highly durable coat 
It creates a waterproof layer on wood surfaces 
Polyurethane can be used on outdoor projects 
It offers superior heat and chemical resistance 
It protects wood surfaces from moisture, scratches, and dents 

Cons

Some polyurethane types, especially oil-based varieties, turn yellow over time. This can alter the wood color. 
Polyurethane does not accentuate the wood grain  

Recommended Polyurethane

Tung Oil Vs Polyurethane Side by Side 

The primary difference between Tung oil and polyurethane is that Tung oil is a natural product while poly is a synthetic finish. 

However, the differences do not end there. This section explores the differences between Tung oil and polyurethane in detail to help you decide better between them for your woodworking projects.

1. Tung oil vs polyurethane: primary uses 

Tung oil is primarily used to nourish the wood. It penetrates the wood grain, enhancing it and making the wood character come out better. 

Wood surfaces treated with Tung oil tend to look polished and more beautiful. Polyurethane, on the other hand, is primarily used as a sealant.

Thinned polyurethane can be used as a wood sealer, going on to bare wood to even out the pores and ensure better finishing. 

You can add water to water-based polyurethane and solvents such as mineral spirits to oil-based polyurethane to thin it. 

Polyurethane is a viscous liquid that dries to form a tough layer on wood, metal, plastic, concrete, and other surfaces when not thinned.

This film-forming quality makes it an excellent sealant. Often, you can apply polyurethane over stained wood surfaces to make them waterproof and scratchproof. What about tung oil? Can tung oil be applied over stain? Find out.

2. Tung oil versus polyurethane: wood protection  

Tung oil soaks into the wood pores, blocking them and making the wood relatively water-resistant. However, the protection wears out over time, leaving the wood vulnerable to moisture damage. 

As such, you must always reapply Tung oil at least once every year to maintain its protection. Even though Tung oil protects the wood against water and moisture damage, prolonged water exposure can still cause water damage to wood treated with Tung oil.

The oil gives wood some level of moisture resistance, but it does not make the wood waterproof. In contrast, polyurethane forms a tough coat on the wood surface, sealing it off from the external environment.

This way, polyurethane forms a barrier between the wood surface and the external environment, making the wood waterproof and weatherproof. 

Since the resin (poly) dries into a tough layer on the wood surface, it makes the surface scratch-resistant. Therefore, wood surfaces covered in polyurethane can significantly resist dents, chemicals, and heat damage. 

Tung oil does not adequately sit on the wood surface, so it does not primarily offer protection against heat, dents, scratches, or chemicals.

Since it does not form a solid coat on the wood surface, Tung oil is generally not the ideal choice for high-traffic areas. Consider using it on furniture or wood surfaces that do not experience a lot of physical abuse.

3. Tung oil and polyurethane drying times

Polyurethane dries much faster than Tung oil. Wood surfaces treated with polyurethane finish take only 12 to 24 hours to cure.

In contrast, the Tung oil drying duration is 1 or 2 days. Raw Tung oil will take even longer to dry and can go for weeks before fully drying. 

You also need to apply at least 5 to 7 coats of Tung oil to achieve adequate protection. This can significantly prolong the product’s drying time and the overall timeline of your project. 

Now, find out the ideal waiting time for polyurethane coats on hardwood floors.

4. Tung oil vs polyurethane: application  

Professional woodworkers and DIYers apply Tung oil by wiping it onto the wood using a lint-free cloth. On the other hand, polyurethane is applied with a brush, roller, or sponge.

But what brush for polyurethane is best? Find out!

When finishing wood with Tung oil, allow each coat to penetrate the wood for 20 to 30 minutes, and then wipe off the excess oil with a clean, lint-free rag.

After wiping the surface, let the coat dry for 24 hours, and then apply another coat. You need to repeat the process until you have applied the last coat of the oil, allowing approximately 24 hours between coats. 

You may have to wait about three days between coats for pure Tung oil. Any type of Tung oil also wears out relatively quickly, so you must touch up the finish at least once every year.

Tung oil requires about 5 to 7 coats to achieve adequate coverage. So you may want to set aside about a week for the project and additional three days of drying time. 

Polyurethane requires only two coats for adequate coverage. For water-based poly, wait only 2 to 4 hours between coats. (Also find out how to apply wipe-on poly without streaks)

If you use oil- or solvent-based polyurethane, wait between 10 to 12 hours before applying the next coat.

Now, you might be wondering, “Can I apply water-based polyurethane over oil-based polyurethane?” Understanding the compatibility of these two types is essential for achieving a successful finish.

Oil-based polyurethane dries more slowly than its water-based cousin, giving it a longer drying time. However, both types of poly are still significantly faster-drying than any Tung oil. 

Read also: How to clean polyurethane off brushes

5. Tung oil and polyurethane: price 

Prices vary between various brands of both Tung oil and polyurethane. However, Tung oil tends to be more expensive than polyurethane in general.

The relatively higher price of Tung oil can be attributed to the relatively more demanding process of manufacturing Tung oil. The making of Tung oil costs more in terms of money and time, which drives up the price of the final product. 

The oil must undergo a thorough purification process to make it lighter. Tung oil in its raw form can take forever to dry. In contrast, polyurethane has a relatively easier manufacturing process, leading to a relatively lower final product cost. 

6. Durability

Polyurethane is among the most durable finishes for wood and other surfaces. It is a liquid plastic that dries to form a tough film on the wood surface. 

Whether water-based or oil-based, a single application of poly is usually all you need to keep your wood protected from scratches, moisture, dents, and moisture for ages. 

While other hard-wearing topcoats like shellac can only go up to three years, polyurethane can last up to a whopping two decades. And a single application is all you need for polyurethane. The product does not require reapplication over time.

However, while Tung oil is top on the list of the most durable natural finishes over linseed oil and shellac, it is nowhere close to polyurethane in terms of durability. 

Surfaces treated with Tung oil require reapplication at least once every year to maintain the protection. The oil lasts even less time in high-traffic areas. 

So, polyurethane is far more durable than Tung oil, even though both products offer some protective benefits to the wood surface. 

Interesting post: Can I polyurethane over boiled linseed oil?

7. Polyurethane vs Tung oil: water resistance 

Since Tung oil penetrates the pores in the wood, it blocks them, giving the wood some water resistance. However, Tung oil does not make the wood waterproof. Therefore, prolonged exposure to water is not recommended as it can still damage the wood. 

Because Tung oil does not make wood waterproof, it is not recommended for outdoor use. Polyurethane provides superior moisture and water resistance than Tung oil.

Since it forms a solid layer on the wood surface, water cannot penetrate the wood to damage it. Polyurethane is considered a liquid plastic.

This means it has a unique chemical composition comprising of particles that are tightly bonded together to make it impossible for water or moisture to penetrate.

8.Tung oil versus polyurethane surfaces: cleaning and maintenance 

Since both Tung oil and poly are film-forming, they are both easy to clean. However, polyurethane forms glossy surfaces that make cleaning and maintenance a breeze.

Polyurethane surfaces also offer superior chemical and heat resistance, making them significantly easier to maintain. 

Due to Tung oil’s limited resistance to substances like chemicals, it leaves wood more vulnerable to staining and chemical damage. Tung oil surfaces are also susceptible to scratching and denting.

Such surface imperfections create room for hiding dirt and grime, making the surface more challenging to clean and maintain. Overall, Tung oil allows the wood to absorb some stains and dirt, and this makes it more challenging to clean.

On the other hand, poly creates a barrier that dirt and filth cannot penetrate. Such surfaces that resist dirt and stains are much easier to clean and maintain.

9. Tung oil versus poly: food safety

Real Tung oil is food-safe once it has cured. The product is derived from organic sources, with zero solvents added to pure Tung oil. This quality limits your exposure to volatile organic compounds (VOCs) when you use Tung oil.

Even though polyurethane film finish contains chemicals, it equally becomes food safe once cured and posts no known health risk.

The rule of thumb is to let the polyurethane surface cure for 30 days before using it for food processing applications.

10. Polyurethane vs Tung oil: color

Tung oil and polyurethane are clear-colored. However, the oil has an amber tone that transfers to the wood. This tone helps accentuate the wood grain and natural character, giving it enhanced aesthetics.

Different types of polyurethane vary in clearness, with water-based poly being clearer than oil-based versions. Oil-based polyurethane can have a yellowish tint or turn yellower over time.

Still, polyurethane does not accentuate the wood’s natural character like Tung oil. Read more here on how to darken wood with tung oil.

Danish Oil Vs Polyurethane

Danish oil and polyurethane are two popular finishes for wood surfaces, each with its unique characteristics.

Danish oil is a blend of oil and varnish, providing a rich, warm appearance that enhances the wood’s natural beauty. It penetrates the wood and offers a satin sheen. It’s easy to apply but provides less protection against water and heat.

On the other hand, polyurethane offers a durable and water-resistant finish, suitable for high-traffic areas and outdoor use. It provides a clear, glossy or satin finish, but it may be more challenging to apply and may require longer drying times.

The choice between the two depends on the desired look, level of protection, and application requirements. You should also note that you can put a wipe on poly over Danish oil for a better look.

FAQs

Is Tung or polyurethane better?

Polyurethane is the better choice for high-traffic areas because it forms a protective layer over the wood surface. It protects the wood against scratches, dents, and water damage. It is also highly durable and can last for up to two decades.

Is Tung oil a durable finish?

Tung oil is the most durable option among natural oil finishes. It surpasses linseed oil and shellac in durability and water resistance but is far less durable than synthetic finishes such as polyurethane.

Does Tung oil make wood waterproof?

No, Tung oil does not make wood waterproof, unless it is an oil varnish blend. It penetrates the wood and blocks its pores, making the wood resistant to water and moisture. However, the wood does not become 100% waterproof.

Read also: How to make homemade wipe on polyurethane.

Conclusion 

When considering polyurethane versus Tung oil finish for your wooden projects, polyurethane comes on top in most aspects.

It is far more durable than Tung oil, offers more protection against moisture damage, scratches, and dents—and is easier to apply.

Consider Tung oil over polyurethane only where your main aim is to nourish the wood, preserve its natural character, and accentuate its grain.

Further, find out if you can put polyurethane over tung oil.