How to Apply Tung Oil? – Beginner’s Guide
Used as a waterproof base over furnishings, tung oil is a great alternative to other drying oils such as walnut oil, soy oil, or linseed oil. It’s usually extracted from the seeds of tung trees, which are native to China and a few Asian countries.
Despite its divisive accessibility, tung oil is a favorite among furnishings due to its environment-friendly and versatile use.
It provides a beautiful finish that protects the wood from water, dirt, and dust easily. Thus we will discuss today how to apply tung oil properly to the wooden furniture so that you can get that beautiful and durable finish.
Types of Tung Oil Finishes
There are primarily two types of tung oil finishes that are being used in the market, and they are each known and admired for their benefits. For instance:
Pure Tung Oil
This is the purest form of the oil, which means there are no additional additives such as VOC or any other chemicals.
And this, however, results in a long, drawn-out process. It usually takes at least two days for each coat to harden, and you will need at least 5 to 7 coats before you can have a protective durable finish.
Regular reapplication is required once every week for a month and then once every month for a year, and later, from the second year onwards, once every year. The result is a beautiful, honey-like finish by showing perseverance and resilience.
Dark Tung Oil
Usually, they are darker in color due to the added non-toxic naturally occurring resinous hydrocarbons or solvent to keep those resins. The resins are essentially non-carcinogenic and do not contain any PCBs. However, it does speed up the drying and coating process.
It also provides a more protective and durable coating than pure tung oil, as it dries through oxidation and not evaporation. The difference in result is the darker and matte finish but more durable and a little less environment-friendly.
How Much Tung Oil Should We Apply?
Before we answer that question, the one that needs answering before is ‘How much tung oil do we apply?’ and the answer is fortunately quite simple.
To cover 400 square feet, you will require a gallon of tung oil or so. However, depending on the surface and how porous it is, that usually differs.
For instance, using pure tung oil in a porous surface, you may need up to 5 gallons or the same surface area to have a durable coating.
However, dark tung oil with already added resins can cover the same surface with lower amounts of coatings to have the same durable protective finish. Usually, the volume for dark tung oil comes down to half of the pure tung oils.
How to Apply Tung Oil?
Here, I’ll walk you through the process of applying tung oil.
Step 1: Clean the Surface
The obvious step before applying tung oil to the surface is cleaning the said surface to ensure that there is no dirt, dust, grease, oils, or any other contaminants, which may cause an obstacle to the process.
Cleaning the surface not only ensures smooth application, but it also ensures the durability and resilience of the oil finishing.
Firstly, take a sanding paper and sand the surface to get rid of any previous coating, dirt, or grease as tung oils can be applied on fresh surfaces or over tung coatings to get the preferred results. This can be easily achieved without any sanding machine, as the process is quite simple.
150-grit sandpaper is highly recommended to sand and then vacuum to clean up any extra debris or dust. At last, use trisodium phosphate to further clean the surface to ensure no remnants of grease or oil and then proceed to the second step.
Step 2: Make the Oil Thin
Thinning the oil makes it easier for the coating to apply and faster for the coating to dry. Usually, pure tung oils can penetrate well enough. As they have a lot of wooden fibers and pores, a thinner helps the oil to penetrate further.
Usually, tung oils come out of the jar pre-thinned such as Half and Half, but if you’d rather do the process yourself, there are a few options for you to go through.
You can thin the oil by adding either mineral spirit, paint thinner, or Citrus Solvents. Usually, they are combined with equal parts. But for different surface finishes, you can also use 7 parts solvent to 3 parts oil for the first coating.
Then 1:1 for the second coating, and 4 parts solvent to 6 parts oil to the third coatings, usually decreasing the solvent portions with oil portions further down the process.
The thinner your solvent is, the deeper will the oil penetrate the surface. However, thinners are not necessary for surfaces such as metal or concrete or weathered woods.
Step 3: First Coat
For the first coat, the tung oil can be applied with a natural bristle brush or sponge or a clean cotton rag that you can procure by padding up an old t-shirt. These few methods are preferred to avoid any harsh lines.
The pro tip is to start with places that are hard to reach or away from the vision of the eyes to ensure that any problems that are created could be rectified as well as there would be no unnecessary contacts later.
Apply the oil in the direction of the wood to ensure that it saturates the wood as much as it can.
And for the initial few coats, apply generously so that it has a wet appearance. However, the oil should be evenly spread, and there should be no formation of puddles.
Step 4: Wait and Reapply
After the first coat has been applied, wait until it has been properly absorbed. Obviously, the time differs based on the type of tung oil you are using.
After you can see the oil has been completely absorbed, move on the second coat. Repeat this process for the number of coats it would require.
Decorative items usually are satisfied with 2 to 5 coats, while functional utensils and surfaces require 3 to 7 coats depending on the finish.
This step would be finished when 80% of the surface would remain glossy for at least 40 minutes, which means the wood has now been completely saturated.
Step 5: Cure and Reapply as Necessary
The last step is cleaning up the surface with a clean, soft rag and then letting it cure for at least 30 days. During this time, the surfaces should be kept away from direct heat and sunlight.
Moreover, no heavy objects should be placed onto the surfaces to avoid any unnecessary harsh lines while curing. After the curing process is done, no other artificial sealing is necessary as it naturally seals itself.
As for reapplication, the functional surfaces that are being regularly used need heavy regular application while the decorative items need comparatively fewer applications. Of course, the number of reapplications also depends on finishes.
Advantages of Tung Oil
It’s not just among carpenters and woodworkers; people who are interested in wooden crafts, architectures, and hobbyists love tung oil due to the following reasons.
Firstly, it is versatile. Material starting from wood to bamboo, stonework, concrete, or even metals can benefit from it. It’s not only used for furniture and cabinets but also a favorite for delicate objects such as musical instruments and cutleries.
It doesn’t darken with age as it hasn’t been polymerized or hydrolyzed. And it would also not mold very easily or turn rancid. It moves with the wood in such a flexible way that it can contact and expand seasonally with the wood.
- Complement the Natural Patterns of the Wood
Its clear structure helps it complement the natural patterns of the wood. And it is also environment-friendly due to the lack of hazardous chemicals in it.
Unlike a lot of other topcoats, tung oil in its purest form usually contains no other harmful chemicals such as VOC.
We hope you have learned how to apply tung oil the right way. Let us know if you have any more queries.