This is a comprehensive guide for Tung Oil including how to apply it for the best result, when to use a thinner and how to use it, how to store your oil and many more. It covers everything you need to know to use your Tung Oil confidently.
We’ll also fix some common misconceptions and explain advanced pro-level techniques for fine woodwork.
Did I say it is comprehensive? It is quite long because there’s so much to talk about! If you want a brief application guide for general use, feel free to use our downloadable pdf guide here:
But if you want an advanced knowledge and use your Tung Oil like a woodwork master, read on!
Before you start
Tung Oil is indisputably the best natural oil wood finish for wood protection based on its oil composition and performance (far superior to more commonly used Linseed Oil). Check our natural wood oil guides to see the comparison of different natural drying oils and the benefits of Tung oil. On this page, we’ll focus more on the application side.
What can you use Tung oil for?
Tung oil gives strong structural protection, water and mould resistant, food-safe and pet-safe. It can be used for surprisingly wide variety of applications such as:
For interior: fine furniture, kitchen cabinet, worktop, doors, window frame, floors, staircase, panelling etc
For food-contact, for animals and children: cutting board, bowls, spoons, animal cages, bird house, beehive, children’s toys etc
For outdoor: garden furniture, decking, planters etc
How it works & which Tung oil to use
The key principles of Tung oil, in short, is that it polymerises (hardens) when exposed to oxygen. This is called ‘curing‘. It doesn’t create a surface film, instead it penetrates the wood and harden inside the fibres to protect the wood structurally and from water and mould. Higher temperature accelerates the oxygen reaction (faster curing). Humidity and cold slows it down.
You can use it neat /undiluted, or thin it with solvent. It penetrates many wood well without the need of solvent.
There are 3 types of Tung oil in the market. Tung oil mixed with solvents and driers, Polymerised Tung oil and Pure Tung oil. Often what’s sold as ‘Tung Oil’ is a blend of oil, solvents and driers to make it thinner (Tung oil is thick) and dry faster. Polymerised Tung oil is heat treated and thickened even more to speed up the curing process.
In most cases, it is best to use Pure Tung Oil.
If you choose to thin it (see below to see if you need it), we recommend choosing Pure Tung Oil and mix your own choice of solvent to thin it when you need to use it.
This is because you can control the purity and quality of your thinner, the quality of the oil itself, adjust the amount of the thinner based on your wood and application. Pre-mixed oils often contain more chemicals beyond just solvents that you probably don’t want. Pure Tung Oil also keeps better for longer without the solvent, so it is best to keep your pure oil and solvent separately and mix them only when you need.
For all these reasons, mixing your own solvent gives you the best result.
Checking your oil
Pure Tung oil has
- beautiful amber colour
- thick & viscous consistency
- mild nutty smell
Some may think the smell resembles chip fat. This is normal for raw drying oils because they share similar fatty acid profile to cooking oils. It is not rancidity, but the natural odour of the oil.
Tung oil doesn’t go rancid like cooking oils. Instead, old tung oil starts to thicken, gel, or form skin because it slowly polymerises when exposed to air.
This polymerisation is exactly what you want after the oil is applied to wood, but not while it’s still in the bottle.
So check that your tung oil pours smoothly, similar to runny honey, and has no lumps or stringy bits.
Tools
You can apply tung oil with a brush, a sponge brush, or a lint-free rag.
All three work — it just depends on your preference. And whatever you choose, you’ll still need your lint-free rags for buffing.
Be careful with brushes.
Tung oil cures into a hard resin, so any oil left in the bristles will make your brush rock hard and unusable.
Wash it thoroughly with soap and hot water, or with a solvent such as mineral spirits or citrus thinner (though expensive for washing brush). Make sure no oil remains at the heel of the bristles.
Lint-free rags are simple and give good control, but they can absorb a lot of oil, so you may use more product.
Sponge brushes waste less oil because they don’t soak it up as deeply, which is why some people prefer them.
Cautions
Tung oil itself is only mildly flammable and you needn’t worry about it. But the danger comes from the oil-soaked rags.
When tung oil oxidises, it naturally generates heat. If oily rags are crumpled, piled, or sealed in a container, this heat can build up and may lead to spontaneous combustion. So never crumple them up and toss it in the bin!
If you use rags, spread them out flat , hang them to dry with good airflow until they are completely hardened. Only then should you discard them.
This safety precaution applies to most natural drying oils, including linseed, walnut, and soy-based oils.
Preparing the wood
Tung oil must be applied to bare, clean wood. It can also be applied to dyed or stained wood without any top-coat. Wood must be porous without any barriers for absorbing new oil.
Remove any previous finish, wax, grease, or oil if there’s any.
Lightly sand the surface (180–240 grit), then remove all dust with a vacuum or a clean cloth.
A clean, dry, dust-free surface helps the oil soak in evenly. Any remaining dust could mix up with oil and dry on the surface, so you want to avoid that.
Thinning the oil
Tung oil can be used either neat (undiluted) or thinned with a solvent.
Most woods absorb pure tung oil well, so using it neat is fine, especially for small objects, toys, and items that don’t need deep penetration.
When to use tung oil neat
Use pure tung oil when the item:
- may be chewed (animal cages, small pets, baby toys)
- is used for food contact (exception for hardwood cutting board)
- doesn’t need deep structural penetration
- is a small or decorative piece
- is used with softwoods that absorb oil easily
Solvents are unnecessary for these applications.
When thinning is helpful
Thinning improves penetration, workability and levelling / even absorption.
When you’re working with dense and hard wood, when you want to give more durability and protection to your item, when you want that perfect cure and finish for aesthetic work, i.e. fine cabinetry, furniture, kitchen cabinet, exterior work etc, you will want to thin your oil.
You may also want to use it for your hard wood cutting board even if it’s a food-contact item, to ensure the wood is more deeply protected from water and mold. We have a thorough guide for the best method for Cutting Board finish and maintenance in that case.
Which solvents to use
You can thin tung oil with:
- our Perfect Cure Oil Thinner (recommended for best curing behaviour)
- high-quality mineral spirits
- citrus solvent / d-limonene
See our How to Choose a Solvent page for a full comparison.
How much to thin
You can mix solvent in any ratio depending on how thin you want the oil.
A common method for cabinetry is:
- First coat: 50–70% solvent
- Second coat: 30–40% solvent > gradually reducing in consequent coats
- Final coat(s): 0-10%
This gives excellent penetration at the beginning and maximum durability at the end.
Applying the oil
Apply the oil with a brush, sponge brush, or lint-free rag. Add a moderate amount, don’t create a puddle with too much oil.
The wood will begin absorbing the oil immediately. Leave it to soak for about 30 minutes.
Once the surface stops absorbing, buff thoroughly with a clean rag to remove all excess oil. This is an important step — tung oil should not be left sitting on the surface.
Allow the coat sit for 24–48 hours before applying the next one. We find applying it the following day works perfectly fine in normal room temperature.
If the weather is cold or humid, you may need to wait longer. A warm, dry indoor environment is ideal, but keep the piece out of direct sunlight.
The key to a good tung-oil finish
Always buff the surface well between coats so no wet oil remains on the surface. Any excess left on the surface will wrinkle, turn gummy, or delay curing.
Use your lint-free rag in circling motion like you’re polishing the surface. Watch for more oil sipping through to the top. If you see any, buff it off!
When to stop
With each coat, the wood will absorb a little less. Only apply thin layers as you progress. Eventually you’ll notice:
- the oil remains on the surface longer
- oil from deeper in the wood may weep back out
This means the wood has reached saturation and cannot take in more.
Keep an eye on the surface and continue buffing away any oil that rises to the surface as the coat cures.
The number of coats varies depending on the wood and the level of protection you want.
Some people find two coats of neat tung oil is enough for their project. Others prefer a fuller finish with gradually thinned coats before finishing with pure oil. We sometimes see people using 8-10 coats. There’s no fixed number – as long as the wood drinks more oil, you can keep going. It will make your wood super strong and thoroughly protected. Just make sure to stop when the wood can’t take it anymore and leave no oil sitting on the surface.
The final look
A cured tung-oil finish has a low-lustre, satin sheen. It is a beautiful natural look.
However, you can use ‘Slurry Sanding’ technique to create a super smooth, almost mirror-like finish using Tung oil, suitable for fine objects and furniture. This is done after the cure, not between coats. It is explained lower down in this article.
Limits
Tung oil is a penetrating finish to protect the wood structurally, not a surface coat.
If you want a real gloss on the surface of your wood (beyond the mirror polish look from ‘Slurry sanding’ technique), you would need additional top-coat like shellac or varnish.
Because there’s no film on top, it will not prevent physical surface damage like scratches. If you need a heavy-duty surface protection in high-traffic area or need to clean it with strong detergents regularly, the best thing to do is to put polyurethane finish on top that creates an impenetrable film surface. This is probably not what you want to do in most cases when you choose a natural Tung oil finish. But just keep in mind of some limits.
Curing
Tung oil needs time to cure fully. This is the only disadvantage of using natural oil without any chemical or metal driers. But if you can wait for a few weeks, it is totally worth it. It definitely makes you appreciate the final project more!
After the final coat, allow the piece to cure for around 4 weeks, or longer if the weather is cold or humid. Tung oil cures faster in warm, dry conditions. Cold or humid environments slow the oxidation process, meaning tackiness may last longer and the final hardness will take more time to develop. For best results, apply and cure your finish in a stable, moderate indoor environment out of direct sunlight.
If you’re working on an outdoor project, choose dry and warm season (if that’s possible!)
During this curing period, the surface will be dry to the touch and can be handled lightly.
If you’ve finished a floor, you can walk on it gently, but avoid shoes, dragging furniture, or heavy use until the full cure time has passed.
Solvent note:
If you thinned the oil with a solvent, it will evaporate as the oil cures.
The solvent helps the oil penetrate deeply, but the surface may feel slightly tacky until it has fully evaporated and the oil has polymerised.
Buffing between coats and providing good airflow will help the solvent escape and ensure an even cure.
The finish continues to harden throughout the curing period, developing its full water resistance, durability, and satin sheen only once fully cured.
Food-contact items:
Once fully cured, pure tung oil is food-safe.
For items that will be washed regularly (cutting boards, bowls, utensils), wait until the oil has completely cured before washing.
Maintenance
Tung oil is a robust, protective finish, but good maintenance is essential to keep it looking beautiful and to extend the life of the wood.
Clean with mild soapy water and a soft cloth. Avoid using harsh chemicals or abrasive cleaners. They can damage the surface.
You can refresh worn-out, or dried areas with additional tung oil. For re-oiling, thinning the oil helps. Use about 2 parts solvent to 1 part oil to make it easy to penetrate. As before, cure fully before normal use.
You can also apply natural wood wax on a regular basis. This will help protecting it from the wear.
If you’re maintaining food-contact items (the ones you wash regularly), check out our cutting board article. You’ll find some important maintenance principles there.
Storing the oil
Store your tung oil in a cool, dark place, away from direct sunlight and heat.
When closing the bottle, make sure the lid and bottle threads are clean, with no oil residue. Wipe them thoroughly before sealing. Otherwise the oil on the threads will go hard and make it a real pain to unscrew.
Tip for small quantities: If your container is large and you have only a small amount of tung oil left, decant it into a smaller glass jar with a tight-fitting lid. This reduces the air volume in the jar, slowing down thickening or skin formation so your oil stays fluid for next use.
The same goes for any Tung oil and solvent mix left over, store it in a small glass jar with minimal air volume, kept in a dark, cool place.
Tung Oil Myths
Here are a few common misunderstandings about Tung oil that are causing some confusion.
Myth 1: “You must wait for each coat of tung oil to fully cure (days or weeks) before applying the next.”
Reality: Not only you do not need to wait for full cure between coats, you probably shouldn’t wait too long. Tung oil should be recoated long before the previous layer has fully cured so the oil near the surface doesn’t harden, as this will prevent more oil penetrating and saturating the deeper fibres evenly when you apply the next coat. The typical recoating window is within 24-48 hours in a normal room temperature. In that time, the previous coat of oil sinks in deeply but doesn’t harden.
This idea probably comes from thinking Tung oil applied later blocks oxygen exposure to the previously applied oil inside the wood.
It is true that the first coat will cure faster if left alone as less oil in the wood means more oxygen allowance for the unit volume. But if it hardens, it would hinder the next coat to soak in sufficiently for full saturation we’re aiming for.
When you apply it to hard wood without thinning, the oil may sit on the surface without good penetration and cures before you add the next coat, that could block the oxygen diffusion and prevent more oil to penetrate. To fix that, you need to thin the oil and apply the next coat before the first one cures.
Myth 2: “You must sand between each coat of tung oil.”
Reality: You do not need to sand between coats of pure tung oil.
Drying oils don’t form a film that needs “keying” between coats like varnish or polyurethane. There’s no adhesion issue, so you don’t need to sand for that reason.
If you need to knock back any raised wood fibres, or smooth nibs and rough patches that you notice, you may sand it carefully before the next coat.
Raw tung oil can stay soft or tacky during early cure stages, so sanding at the wrong moment causes problems. It can gum up the abrasive and dust, create muddy smears or burnish the surface that hinders the next coat soaking in properly.
So, if the surface feels slightly tacky, damp, or draggy — don’t sand.
If you must, wait until the surface feels fully dry to the touch, lightly remove the issues with very fine grits (320 – 600). Buff well with cloth.
Myth 3: Adding more solvent makes tung oil dry faster
Solvent dilutes the oil to thin it and evaporates in time. It doesn’t change the oil chemically or make the oil dry faster. Large amount of the wet solvent evaporating fast would give an impression of ‘drying faster’, but the oil itself will dry at the same speed with or without solvent.
What will make the oil dry or cure faster is more oxygen, higher temperature or the use of siccatives/driers. Thin coats and buffing allows more oxygen exposure for each coat. Warm temperature (Ideal conditions: 20–25°C (68–77°F)) speeds up the reaction rate with oxygen. Siccatives/driers will chemically catalyse the oxidation process and speed up the polymerisation.
Advanced Techniques
Slurry Sanding / Wet Sanding for a Super Smooth Tung Oil Finish
Slurry sanding is a wet-sanding technique to create a completely smooth, polished look.
A fine abrasive would create very fine wood fibres (saw dust) which will be blended with wet oil. This ‘slurry’ of the oil and fibre mixture will fill the pores of the wood surface. When it cures, the surface will be totally flat and smooth to touch.
This technique can be used with Tung oil, but also with any other oil or shellac, so we’ll share full detailed process on another article.
Speeding Up Tung Oil Curing
Certain metal salts (cobalt, manganese, zirconium) are called siccatives or driers. They catalyse the oxidation process, speeding the polymerisation of the tung oil. It’s best to avoid them if you’re making food-safe, child-safe, pet-safe items.
Many commercial Tung Oils mixed with solvent or sold as ‘Boiled / polymerised’ Tung oil already contain siccatives.
If you’re using pure Tung oil, you can buy the siccatives and mix some in yourself.
Using Polymerised Tung Oil
You can also buy partially polymerised Tung oil instead of using pure Tung oil. Look for one with only heat treatment without siccatives/driers if safety is important.
The oil is cooked with high-heat so it is partially polymerised, which reduces the time for you to cure it. Without the siccatives, full cure still takes time. It will roughly reduce the drying time by 12-24 hours and curing time by 1-2 weeks. It is more expensive. They’re thicker and harder to use so you’ll need to use more solvent.
We don’t find the reduction in drying and cure time that dramatic to justify the higher cost and more need for solvent. Processing the oil in high heat over extended period is quite energy-heavy. Waiting just a bit longer without all that seems fine in most cases. Also, heavy viscosity could make even application difficult if you don’t thin it liberally. Pure Tung oil is easier to apply and you tend to get better result.