Tung oil and polyurethane are two finishes that protect wooden surfaces from moisture and water. But, what’s the difference between Tung oil and polyurethane?
Tung oil is a natural oil extracted from the Chinese Tung tree, while polyurethane is a synthetic finish gotten from several resins, urethane compounds, and solvents. To stick, Tung oil needs to penetrate a surface, while polyurethane doesn’t.
However, Tung oil takes longer to dry than polyurethane. On average, Tung oil fully dries within 3 days, while polyurethane dries within 48-72 hours.
Tung oil is a natural finish gotten from the extracts and seeds of the Chinese Tung tree. It’s an old and traditional finish used on wood surfaces such as furniture. Tung oil is a penetrating film (coating) that soaks into the wood fibers to stick.
You must apply 5-7 coats of Tung oil for proper coverage. This prolongs the dry time of Tung oil. On average, Tung oil takes 3 days to fully dry while Raw Tung Oil takes weeks to dry. Tung oil forms a hard top layer that isn’t resistant to scratches or stains when dry.
You must re-apply (touch-up) Tung oil every year. That’s because Tung oil isn’t durable and wears off fast. This means Tung oil isn’t a good choice for high-traffic surfaces.
Here’s where you can use Tung oil:
- To get a glossy finish, use Tung oil.
- Tung oil reveals the wood grain.
- You can use Tung Oil to cover and protect the wood.
- Tung oil is used on wood décor and sculptures to reveal the details and carvings in the wood.
Polyurethane is a synthetic varnish made by combining solvents, resins, and urethane compounds. Polyurethane forms a glossy clear coat resistant to water, moisture, and scratches when dry.
The main ingredient in polyurethane is urethane compounds. Urethane is a plastic-like substance that is flexible, moisture-resistant, and durable. Aside from urethane compounds, polyurethane also has several additives in its formula designed to reinforce the finish. This makes polyurethane a strong finish.
There are two main types of polyurethane; oil-based and water-based polyurethane. The oil-based type is more common because it is stronger and more durable. Also, you only need 2-3 coats of oil-based polyurethane. On the other hand, water-based polyurethane needs 4-5 coats, but the sealant is easier to apply.
You can use polyurethane:
- To seal stains and paints.
- To protect the wood from water and moisture.
- You can use polyurethane on high-traffic surfaces.
- For outdoor surfaces.
- To protect floors from scratches.
- Over paints to make the finish moisture-resistant.
Polyurethane vs Tung Oil
To compare polyurethane and Tung oil, we will use the features of both finishes and see which finish is better.
Here is a table that shows the major differences between Tung oil and polyurethane:
|Color||Tung oil has an amber-like tone||Polyurethane is a clear coat so it doesn’t have any color|
|Application||Tung oil is applied with a cloth||Polyurethane is applied with a paintbrush or spray gun|
|Price Tag||Expensive||Cheaper than Tung oil|
|Moisture Resistance||Average||Very good|
Tung oil adheres or sticks better to wood than polyurethane. This is because Tung oil penetrates the wood pores to stick, while polyurethane sits on the surface. When you apply Tung oil, the wood oil soaks and binds to the wood grain.
Since Tung oil penetrates the wood pores and fibers, it’s harder to remove it from wood. In most cases, removing Tung oil from wood will damage the wood surface.
On the other hand, polyurethane binds (sticks) to the top layer of wood, meaning the sealant has a weaker adhesion to the wood.
Polyurethane protects wood better than Tung oil. This is because polyurethane is a hard and moisture-resistant sealant that protects wood from scratches, dents, and water.
Tung oil also protects the wood but not as good as polyurethane. That’s because Tung oil doesn’t have a hard and rigid layer as polyurethane. Tung oil is prone to scratches, stains, and water rings, so it’s not the best finish to protect the wood from damage.
Polyurethane will last longer than Tung oil because it has a more durable, harder, and stronger finish.
On average, polyurethane lasts up to 10 years (if properly applied), while Tung oil won’t last more than 1 year. You must re-apply (touch-up) Tung oil every year because the finish wears off.
Polyurethane is a clear coat finish that doesn’t give any color to surfaces. Instead, polyurethane forms a transparent layer that reveals the color and texture of the surface underneath. This is because polyurethane doesn’t have paint pigments on its formula.
To get a color finish with polyurethane, you must mix it with flat or acrylic paint. The tinted polyurethane will have a colorful and durable finish. Also, oil-based polyurethane tends to yellow over time; this happens when you apply too many coats.
On the other hand, Tung oil has an amber-like or gold color. The color of Tung oil is similar to the natural color of wood.
You can apply polyurethane with a spray gun, paintbrush, or roller. Polyurethane also comes in ready-to-use spray cans. So, applying polyurethane is easy. On the other hand, you can apply Tung oil with a rag. That’s because Tung oil must be wiped on the wood.
For small surfaces, applying Tung oil is easier than polyurethane. However, for large surfaces, applying polyurethane is easier.
Generally, Tung oil costs more than polyurethane. That’s because making Tung oil is harder than making polyurethane.
The Tung tree where Tung oil is gotten from is only native to China. This makes it difficult to get the needed resources to make the wood oil. Also, Tung oil must go through processing to make it lighter since raw Tung oil takes forever to dry.
On the other hand, polyurethane is easier to manufacture.
Polyurethane offers better moisture resistance than Tung oil. The presence of urethane (plastic-like) compounds in the polyurethane formula makes it impossible for moisture (water or oil) to penetrate the polyurethane coating.
Also, the polyurethane paint particles are tightly bonded, making it even more difficult for water to get through.
Tung oil is also moisture-resistant, but after a while, water rings and irregular lines will form on Tung oil coating due to moisture exposure.
Cleaning and Maintenance
Cleaning polyurethane is easier than cleaning Tung oil. That’s because polyurethane doesn’t absorb stains or filth. So, you have less cleaning to do with polyurethane. Also, polyurethane has a slick finish, so you can wipe off the dirt and stains with a dampened rag.
On the other hand, Tung oil has a softer texture, meaning stains and filth stick to the Tung oil. So, you must clean Tung oil more frequently. Also, Tung oil isn’t as moisture-resistant as polyurethane, so if you use a solvent to wipe Tung oil, the coating may wipe off too.
Do You Need Polyurethane or Tung Oil?
It’s difficult to choose between polyurethane and Tung oil, but here are a few factors to consider to make your decision easier:
- Budget – If you have a low budget, use polyurethane. That’s because polyurethane costs less than Tung oil.
- Moisture-resistance – If you need a finish with better moisture-resistant features, use polyurethane. Polyurethane can protect a surface from constant moisture better than Tung oil. You can also wash and clean a polyurethane coating often, and the coating won’t wash off.
- The Application – Applying Tung oil is easier than applying polyurethane. You can apply Tung oil (for small surfaces) with a rag, while you must use a paintbrush or sprayer for polyurethane. However, you must re-apply (touch-up) Tung oil every year, while polyurethane can last up to 5 years without re-applying.
- Wood Protection – Polyurethane offers superior wood protection compared to Tung oil. When dry, polyurethane from a thick clear coat that protects wood from moisture, water, and scratches. Tung oil also protects wood but not as good as polyurethane.
- Color – If you want to deepen the color of the wood, use Tung oil. Tung oil has an amber-like color that will enhance the wood grain color. On the other hand, polyurethane is a clear coat with no paint pigments, so the finish will be transparent.
Polyurethane and Tung oil are great choices as a wood finish. However, polyurethane lasts longer, protects the wood better, and is more durable than Tung oil. But, Tung oil has an amber-like finish that reveals the wood grain and deepens the wood color. Also, Tung oil is easier to apply than polyurethane.
Tung oil is suited for indoor surfaces, while polyurethane can be used indoors and outdoors.