As you may know, I am a big fan of pure Tung oil as a finish for many wood surfaces. I use it for most of my furniture as well as tool handles and carvings.
I think one place it absolutely shines is firearm stocks.
This stock, from a Steven’s 5100 side-by-side shotgun, had 8 coats of pure Tung oil. It has a smooth finish with a nice sheen.
Same gun in a different light.
Why pure Tung Oil is great for wooden stocks
- It is a true oil finish just like the more common Boiled Linseed Oil (BLO) finish.
- It can be a traditional “hand rubbed oil finish” that are common with all older firearms. Firearms have used hand-rubbed oil finishes for over 100 years.
- It is a waterproof finish. Unlike BLO, which has one end of its molecule that bonds to water, Tung oil does not.
- It does not foster mold growth like BLO. Guns are often stored in cases or safes where they get little air flow. This kind of storage is usually good for preventing rust and keeping firearms out of kid’s hands, but the dark environment can also lead to mold growth so it helps to have a finish that does not foster mold.
- It does not darken the wood like BLO. It also does not darken over time.
- Pure Tung oil does not contain nasty metal salts or other drying agents that can damage your skin, like BLO. Pure Tung oil is perfectly safe to put on with your bare hands. using your bare hands is key to a hand rubbed oil finish.
- Easy to refresh or repair, simply wipe on more if needed.
- Can stop at 3 coats and have a nice matte finish that feels like wood and is still waterproof, or can work up to ~10 coats to have a natural built up glossy sheen.
At three coats of pure Tung oil, the stock is fully protected from the elements and has a nice matte finish. Smooth to the touch but still feels like wood. This finish is applied to a 1929 Lefever Nitro Special.
At 5 coats of pure Tung oil the stock is taking on a faint sheen without being too glossy.
At 7 coats of pure Tung oil the finish is noticeably thicker and more glossy. It feels less like wood in the hands, but at the same time does not feel like plastic.
Myths about Tung oil and guns
It doesn’t take long browsing gun forums to run into people asking about Tung Oil as a finish and then receiving tons of advice or myths / tall-tales about disasters with Tung oil. I’ll try to sum up several of them here.
Myth: Tung oil never dries
Tung oil absolutely does cure (dry) but it needs oxygen and time. If you slather on Tung oil until the wood no longer soaks it up (like too many people advise), yes you will have a drying problem because the oil that made it in deep never gets enough oxygen to complete the curing reaction. Tung oil should never be flooded on. Thin coats are the answer. Applied thin and given enough time and or UV, it will cure perfectly.
Myth: Tung oil goes rancid
This is usually a case of mistaken identity. Some other oils including Linseed oil (not boiled) can go rancid. Tung oil does not go rancid. If you have a container that is open and has a bit of oxygen in it, given months or years, it will start to cure in the container and may solidify at the top, forming a bit of a skin. It can not keep forever, but that is not rancid, that is just the top skinning over like almost any other type of finish will do given time.
Semi-myth: Tung oil is hard to use because it dries so slowly
This one has some truth to it. If you apply it thick, or apply it every hour or every day you will likely end up with a mess. Tung oil does cure slowly so applying thin coats and giving it proper time to cure is essential for a good finish. If you are refinishing a stock and want to give it to the person the next day, pure Tung oil is a bad choice of finish. If you are not racing the clock, pure Tung oil can be an excellent choice.
Myth: Tung oil offers no protection against water
This one is 100% false. Pure Tung oil offers fantastic protection against water. I have had my shotgun out many many times in horrible rain and the water does no damage to the wood. The water beads up and rolls right off. Wipe it dry when done and it will look and feel just like it did before getting wet. There is a reason Tung oil was used to waterproof ships. It is fantastic at keeping water out of wood. Large changes in humidity can cause a hard finish to fail as the stock expands or shrinks causing the finish to crack, which allows places for water to get in. Pure Tung oil is flexible and expands or contracts as the wood breathes, it does not crack.
Myth: Tung oil is not a durable enough finish gun stocks
This myth is largely false. Pure Tung oil is more durable than BLO. It is not as abrasion resistant as polyurethane, but it is much more repairable. With a polyurethane or other varnish finish, when you scratch, dent, or abrade it, the finish looks awful and the repair usually involves sanding or finish removal before applying new. Tung oil can simply be re-applied over the top of the damaged areas.
Myth: Tung oil can cause allergic reactions
Tung oil is often described as coming from the “nut” of a Tung tree. Which leads people to think it could trigger people with nut allergies. In reality is comes from the seed of a Tung tree. Being a seed rather than a nut makes it less likely to be an allergen. Anything can be an allergen to the right person (wrong person?) but it is very unlikely. Once the finish is cured, that risk goes down even more. If you know anyone with a Tung seed allergy, advise them not to lick your shotgun stock.
Myth: Tung oil results in a cloudy finish
This one is false. Pure Tung oil is more optically clear than BLO. Where it can appear cloudy is when it is put on too thick or too fast. If put on too thick the finish will wrinkle as it cures and small wrinkles can appear less than clear. Keep the coats thin with no excess left on the surface and you will have a beautiful clear protective finish.
Myth: All Tung oil finishes are the same
I do with this were true, but it is not. Some products labeled as “Tung Oil Finish” contain no Tung oil at all. Marketing laws let companies lie to to you in the title. And that creates a lot of confusion. Most “Tung oil finishes” contain some kind of polyurethane or varnish to create a hard thick finish and contain either no Tung oil or small amounts. Others do have a Tung oil base but also contain other things to achieve faster drying times. Polymerized Tung oil is a form of Tung oil is altered in some way to make it start the polymerization process early. Tung oil cures by polymerization naturally, that is what leads to the cured finish. Polymerized Tung oil just speeds up that reaction. Some companies will describe how they achieve the magic, others will not, so it is hard to know what they added to the Tung oil. I prefer truth in advertising, so I stick the Pure Tung oil.
Myth: You have to sand between coats
This is largely false. It is recommended that you sand while applying the first couple coats, but the purpose is to achieve filling of the wood pores with matching sawdust. It is not because pure Tung oil raises the grain or needs mechanical abrasion to make the coats adhere to each other. If you are going for a real glossy finish you might want to wet sand as you apply all the coats, but that is true for any finish, not specific to pure Tung oil. Tung oil adheres to itself just fine so sanding is not needed to make one coat stick to the next.
Myth: Tung oil does not build a film finish
It absolutely does. If you let the previous coats cure properly it will build a transparent film finish in as few as 5 coats. The more coats you apply, the thicker the film.
Myth: Tung oil needs to be thinned
This is largely not true. Pure Tung oil has a thicker consistency similar to honey. However it can be rubbed onto wood and will penetrate just fine. Many people advise that it needs to be thinned so that it penetrates deep and “nourishes” the wood. This is just not the case. Wood does not need to be nourished, fed, or saturated. Thinning only gets in the way of the polymerization process that takes place as the Tung oil cures. The heat of your hand will be all that is needed to get the Tung oil into the pores of the wood.
Myth: Tung oil stinks
Tung oil does have a distinctive odor. It has a kind of nutty smell. BLO also has an odor. I think the odor of BLO is worse, but because of the chemical driers added to it, the finish cures and stops producing an odor faster than pure Tung oil. When pure Tung oil is cured, it has no odor. Any odor is actually a good indicator that you should not apply the next coat. It is easy to touch the surface of the wood the next day and say, “oh this is dry” , but if you smell it and can detect an odor, don’t apply the next coat.
Semi-Myth: Tung oil will weep out of the wood as it cures
This is partially true. If you apply too much pure Tung oil and then wipe off the excess, you may indeed see small specs of oil weep back out of the wood. This is a definite indicator that you applied too much oil in the first place. If you apply just a small amount in each coat, there will be no weeping from you or the wood. Do not ever apply a flood coat or follow ham-fisted advice like “keep applying it until the wood stops drinking”.
Tips for applying pure Tung Oil to gun stocks
Do NOT apply too much Tung oil
Less is more. Putting on too much is the single cause of most of the complaints about Tung oil finishes. Just dip the tip of your finger into the Tung oil and start working it into the wood. Your first application may take up to 10 dips. Your last application may take only one dip.
The first coat is critical, it must cure
If your first coat is not allowed to cure, the wood will keep soaking in the Tung oil on subsequent applications. Give the first coat a week to cure or use the Sun, before you apply any additional coats. If the first coat cures, subsequent coats will be thinner and smaller, so will also cure more rapidly. Go slow initially, to go faster later.
Use Sun for your Tung
UV cured finishes are all the rage right now in the world of woodworking. What most people do not realize is that Tung oil is the original UV cured finish. If you have access to sunlight you can easily put on 1 coat of Tung oil per day. Without sunlight, you can do like one coat every 3-5 days. My Tung oil and Sun finishing process works great for gun stocks.
Keep it off your action
If possible, when refinishing your stock, remove it from the action of the gun. This keeps the Tung oil off the gun. If you can’t separate them, either tape off the metal with blue painters tape or use a cloth to wipe the Tung oil off the metal parts. Will the Tung oil hurt the metal? Not really, but it will create a film finish on the metal that will not look good.
Gunstock finish of choice Pure Tung oil
My choice for a gun stock finish is always pure Tung oil. I have it on all but one of my guns at this point and have had no issues, despite bad environments and poor handling.