Before tung oil forms a hard and moisture-resistant layer, the finish must dry. So, how long does tung oil take to dry?
It takes tung oil a few days to dry. On average, the first coat of tung oil dries within 24 hours. However, it takes up to 3 days for all coats of tung oil to dry. Tung oil takes longer to cure because it cures through oxidization and polymerization.
However, the dry time of tung oil depends on the number of coats, humidity, and ambient temperature. Also, there are a few methods you can use to speed up the drying time of tung oil.
Tung Oil Dry Time Between Coats
Tung oil must dry 24 hours between coats. This gives tung oil enough time to dry and harden before recoating it. However, pure tung oil takes longer to dry than refined tung oil.
On average, pure tung oil must dry for 48 hours before a recoat. Pure tung oil drying time is higher because it has a thicker flow and doesn’t have solvents or additives that make the oil dry faster. On the other hand, refined tung oil takes 24 hours to dry because it has drying additives and solvents that make it dry faster.
If you recoat tung oil too soon, the finish will turn tacky and take several days to dry. If the tung oil turns sticky, you must wipe the excess wood oil off the surface and allow the remaining tung oil to dry.
Factors That Influence Tung Oil Drying Time:
Ambient temperature is the biggest factor that determines the tung oil drying time between coats. The ideal temperature for tung oil to dry is 60-80 degrees (F).
Here are other factors that determine the drying time of tung oil:
You must apply tung oil when the humidity is lower than 50%. If there’s high moisture content in the atmosphere, the room will feel moist and wet, affecting the drying time of tung oil.
If the humidity levels are high than 70%, the dry time of tung oil will be doubled (from 24 hours to 48 hours).
Humidity tends to be higher during cold winter months, so tung oil takes longer to dry during winter. To reduce room humidity, use a dehumidifier.
3. Flow Thickness
The thicker the tung oil coating, the longer it takes to dry. That’s because more oil will be on each coat, and the evaporation rate will be slower.
If the tung oil is thin, it will dry and cure faster. So, it’s recommended to thin the tung oil before applying it. To thin tung oil, use mineral spirits.
4. The Number of Coats
You need 4-6 coats of tung oil for proper coverage. The more coats you apply, the longer it takes tung oil to dry.
5. Air Circulation
Tung oil dries through evaporation. The faster the oils in the tung oil evaporate, the faster the tung oil dries. If the air circulates faster around the tung oil coating, evaporation happens faster, and the tung oil dries faster.
Tung Oil Cure Time
It takes tung oil 3 days to cure. Tung oil curing time refers to how long it takes the wood oil to fully harden and become moisture-resistant. Tung oil cures through oxidization and polymerization, so the cure time is influenced by dry air.
Oxidization happens after the tung oil solvent (oil) has evaporated. After the wood oil is dry, air (or oxygen) gets into the wood oil and hardens the finish; this process is called oxidization. The dry air causes the oils and molecules of tung oil to combine (harden); this process is called polymerization.
The compactness of the tung oil particles is what makes the finish moisture-resistant. So, once the tung oil cures, you can clean, use, and paint over it.
How to Make Tung Oil Dry Faster?
Method 1: Thin The Tung Oil Before Applying It
Thin coats of tung oil dry faster than thick coats of tung oil. So, thinning tung oil before applying it means that the finish will dry and cure faster. That’s because the finish of the thinned tung oil will have fewer oils.
To thin tung oil:
- Get a clean plastic bucket.
- Add the required Tung oil into the bucket.
- Add mineral spirits. To thin tung oil, use a ratio of 2:1 (2 parts tung oil and 1 part mineral spirits).
- Stir the mixture with a paint mixer for a few minutes.
- Apply the thinned tung oil.
Method 2: Improve Air Circulation
The more air circulates around the tung oil coating, the faster the solvent evaporates, and the finish oxidizes. So, increasing the air circulation around the tung oil coating means the finish will dry and cure faster.
You can increase the air circulation by:
- Opening all windows and doors.
- Open the air vents.
- Turning on the fans.
- Applying the Tung oil outside.
- Setting the air conditioner on ‘blow’ or ‘fan’ mode.
Method 3: Use A Hairdryer
The more heat there’s around the tung oil coating, the faster the solvent (oil) evaporates. To increase the temperature around the tung oil, use a hairdryer. A hairdryer will increase the temperature around the tung oil coating and dry the wood oil faster.
Here’s how to do it:
- Turn on the hairdryer.
- Set to medium heat.
- Move the hairdryer over the Tung oil coating for a few minutes.
- Increase the heat of the hairdryer.
- Move the hairdryer over the Tung oil for 60 seconds.
- Turn off the hairdryer and let the Tung oil dry completely.
It’s not advised to dry the tung oil completely using a hairdryer. While it’s tempting to do this, drying the Tung oil completely will cause the Tung oil to crack and peel off. That’s because the tung oil will dry too fast and the paint particles won’t harden naturally.
Method 4: Use A Dehumidifier
If you apply tung oil during winter, you must use a dehumidifier. This is because during winter months, the room humidity is higher than 50%. The higher the humidity, the more it takes tung oil to dry.
Since a dehumidifier decreases the humidity levels, the tung oil will dry faster. All you have to do is to turn on the dehumidifier before applying the tung oil, and keep it running until the wood oil dries.
Here are a few other tips to make Tung oil dry faster.
- Apply Tung oil early in the day to take advantage of the sunlight.
- Apply Tung oil outdoors where there is better airflow.
- Apply light coats.
Tung Oil is Dry Enough If:
The following signs will indicate when Tung oil is dry enough:
- When you can sand the Tung oil – If the tung oil isn’t dry, you can’t sand it. That’s because the sandpaper will get clogged with oils. But, when the tung oil is dry, the sandpaper will move freely over the coating without getting clogged.
- When the Tung oil is moisture-resistant – When the tung oil is dry, the finish will become water-resistant. So, pour a few drops of water over the finish. If the water penetrates the finish, the tung oil isn’t dry. If the water doesn’t penetrate the finish, tung oil is dry enough.
- When Tung oil gets glossy – When Tung oil is not dry, it will appear wet but when the oil is dry, it will be glossy.
Tung oil takes up to 48 hours to dry and 3 days to cure. However, the dry time of tung oil depends on the tung oil type (pure or refined), coat thickness, number of coats, humidity levels, and ambient temperature.
You can speed up the drying time of tung oil by increasing the heat and air circulation over the tung oil coating or by decreasing the humidity levels using a dehumidifier.