# why/when should I use tung oil?



## jrhovde (Apr 27, 2012)

I'm still relatively new to woodworking and I have finished all of my projects using stain and polyurethane. I see a lot of people here use tung oil and there is a lot of good information about what tung oil is. What I really would like to know is WHY people use tung oil and on what applications is it good for. Should I use it on floors, tables, bookcases, etc. Should something go over the top of it?
Any guidance would be appreciated.
Thanks


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## Cosmicsniper (Oct 2, 2009)

Oils in general work to enhance the natural beauty and contrast of the wood. They go on easy and can be replenished over time as long as they aren't topped with some type of film finish, which is certainly an option. Nothing pops a figure quite like an oil, nor makes the wood really pretty. They are an easy alternative to stains, which are mostly just thinned paint.

If you use uninteresting wood in your projects, like pine or poplar, then you'd likely use stains (or dyes). But if you use really pretty hardwoods with awesome figure, then oils will be a big part of your gameplan.

Real tung oil (as opposed to tung oil finish) takes forever to dry, but doesn't yellow the wood quite like other oils and it is more water resistant. It is often used on metal to prevent rust.


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## RussellAP (Feb 21, 2012)

I follow pretty much the same procedure for danish oil that I do for Tung oil. On soft woods it tends to blotch and it can also on hardwoods. I always wipe on then wipe off right away. Don't let it dry on because it leaves a sticky residue that you have to clean off. Just a wipe is all you need. Let it dry about 4 -12 hours depending on heat and humidity and repeat if needed.

Oils like all penetrating finishes will soak deeper into the soft grain, and you may need a pre-color conditioner to keep it from blotching those area's. I suggest a sample of whatever wood you are using as a test piece for finishes.

Oils bring out the natural beauty of the wood like no other product I've used.


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## ClintSearl (Dec 8, 2011)

Oil poly can be manipulated to produce any effect from an oiled look to a high gloss, so learn how to use it. It's a great finish.


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## Wildwood (Jul 22, 2012)

Pure Tung oil is a drying oil, takes time to dry & cure. Matt or satin finish about all can expect, will develop a patina after several years of re-application. Pure Tung oil is easy to apply & repair. Same can be said of polymerized Tung Oil, about the same except dries faster.

Adding solvent to either pure or polymerized Tung oil increases penetration into wood and speeds up drying times.

Oil varnish blends contain oil, resin, and solvent. May or may not contain Tung oil, have to read label on can or check out material safety data sheet MSDS for list of ingredients.

Many oil varnish blends contain cheaper non-drying, semi drying oils, drying oils. Have seen products that contain real small amounts of both Linseed & Tung oils which seems silly because these oil dry differently, but does not matter because amounts so small.

http://apps.risd.edu/envirohealth_msds/MetcalfStore/WatcoDanishOilNatural.pdf

Wiping Varnish contains resin & solvent (varnish-poly). Usually no oil in a wiping varnish, so check ingredient list. Never want to buy a wiping varnish that is over 60% solvent.

Here is a Tung oil wiping varnish with 69% mineral spirits and no other ingredients listed.
http://hazard.com/msds/f2/ckc/ckctz.html

Another Tung oil wiping varnish product without any Tung oil
http://hazard.com/msds/f2/brx/brxhq.html

http://www.popularwoodworking.com/techniques/finishing/oil-finishes-their-history-and-use

When to use depends upon project and product selected, not sure any rules other than understanding end results.


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## a1Jim (Aug 9, 2008)

As others have said tung oil can take a long time to dry a more modern oil base finish will give the same effect,dry faster and harder.

http://www.generalfinishes.com/sites/default/files/Tech-Data-GF-Arm-R-Seal-050311.pdf


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## ClintSearl (Dec 8, 2011)

It's pure myth that an oil will penetrate wood more if it's thinned with a solvent. The solvent may soak in a bit, but the oil won't go any deeper than if it weren't thinned, and that's only a few wood cells deep.


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## Planeman40 (Nov 3, 2010)

Tung oil (made from the tung nut) is interesting stuff. It is an oil, but upon exposure to air it becomes a wax over time. This is why it takes longer to "dry". One thing to know. When you store it, make sure there is very little air in the container or over time it will turn into wax. As I use it up I usually decant (pour) it into smaller and smaller containers, usually Ball jelly jars used for canning that are obtainable from the supermarket. I have also dropped some marbles into the jar to raise the oil level close to the top of the jar.

Planeman


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## ClintSearl (Dec 8, 2011)

Planeman…I don't know where you're getting your information, but pure tung oil polymerizes in the presence of oxygen, forming a relatively hard film. What do you mean by wax?

Heat and chemically processed tung oil like Waterlox, which is mixed with resins, solvents, and driers, will gel in the container, but pure tung oil won't.


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## Planeman40 (Nov 3, 2010)

Well…from my use it gelled up in the can like a wax from exposure to air, which, of course, contains free oxygen. I have never looked into the chemical content. The exterior of my finish buffs up to a warm luster after a couple of weeks after the application similar to wax. If tung oil has a "relatively hard film", is has never been apparent in my use.

My caveat is tung oil should be capped back up with as little air (oxygen) as possible or it will gel up.

Planeman


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## wormil (Nov 19, 2011)

Oil in general offers little to no protection but looks great. Usually used in combination with wax on surfaces that will receive little wear and tear… e.g. cabinets; but not tabletops.


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## Cosmicsniper (Oct 2, 2009)

Not sure that I agree with that, Clint. To some extent, the solvent does work as a carrier, changing the viscosity of the oil. Thinner viscosities of anything will penetrate more deeply. This is why polymerized tung oil is mixed with a solvent, otherwise I'd be too viscous to do the job. But the question can be argued, "How much diluting is required to give more penetration?" IMO, this is the main reason that everybody has their own preference of ratios for oil-varnish blends.

But in porous woods, I think it's obvious that there is a proper mix that best works to get deeply into the wood.


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## RussellAP (Feb 21, 2012)

Cosmic, don't you agree though that it's better to wipe it on and wipe it off as fast as possible. I mean it's going to penetrate no matter what you do but leaving it on just makes it gummy on top. I usually apply a couple coats and find that it's penetrated just fine without a buildup.


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## Cosmicsniper (Oct 2, 2009)

It depends, Russell. I like the process, so I'm likely inclined to put a few applications…never more than three. Other times, I'll just pour a bunch on, let it sit for an hour, then wipe it all off…wiping with mineral spirits to clean off any excess.

I'm convinced that the latter is more effective than the former when you want deeper penetration. I think we are too quick to wipe it off and we don't really let the oil work…and subsequent applications become blocked by earlier coats. Depends on the wood, of course, but I find this to be the case with oak and walnut, which get the bulk of it for me. Maple as well, but that's mostly on curly figured stuff.

Danish oil, which may or may not have varnish in it, would be applied in multiple coats.


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## Cosmicsniper (Oct 2, 2009)

BTW, my philosophy with oil is to make it look good. I'm not interested in complete saturation unless I think it will improve the looks. The exception would be something like a workbench where I'd want to protect it as much as possible from moisture (that doesn't have a film finish), or perhaps something that might stay outside, like a patio chair.


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## RussellAP (Feb 21, 2012)

Cosmic, I'm working some padouk, red oak and black walnut today for a box. I decided to try some Danish oil cherry on the oak and walnut to kind of tie it in to the padouk. All I needed was a shop rag, blue paper towel and I just wiped a little on and it's done. Wiped it right off afterward. 
I think with hardwoods you just don't get the penetration nor do you need it often times. They take on color pretty well from oils.


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## lumberjoe (Mar 30, 2012)

For oils, I tend to follow Bob Flexner's preferred method for application. Blotching should not really be a concern. You are not adding any dyes or changing the color of the wood, you are enhancing what is already there. Colored oils (like Walnut Danish oil for example) are a different story. I have never had any blotching with an oil finish.

1 - Prep the surface as usual. I generally sand through the grits until about 220 (sometimes 180 with really closed grain wood like maple)

2 - FLOOD the surface with the oil. I just pour it on. I am looking for a nice "slick" appearance. I will babysit it for about 30 minutes or so and touch up any dry spots so they are still wet (this could explain why I don't get blotching). I let that dry for as long as it takes - generally overnight.

3 - Once dry, I give it a nice light sanding with some 400 or 600 grit depending on the wood. then clean the dust off

4 - Rub on another coat. not flooding this time, but still babysitting the piece for about half an hour or so and touching up dry spots. After about 45 minutes to an hour, I'll rub off any excess that isn't going to dry.

5 - Let that sit for 10 days to 2 weeks then finish with some sort of varnish/lacquer/shellac.

In my experience, after the 2 coats of oil, that is all the wood will take. Any more than that and you are just asking for a gummy mess.


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## CharlesNeil (Oct 21, 2007)

have 2 issues with "oils", the first is the time it takes to dry , if it does, I make a living doing woodwork and 2 weeks is not acceptable. Second, why, with the modern day oils and resins that dry fast, protect and hold up , why use the inferior ones, is it price, ease of application , I am curious, because I just don't get it .
I have personally tried all the good old combos, linseed oil, tung oil, my issue is , yes they look good initally , but 6 months, or a year down the road, not the case, I understand "renewing them", but my customers are not into reoiling and waxing furniture. 
Not being a smart A** here, I just cant understand why folks would use inferior finishes, and they are , experience for me has proved it.


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## ClintSearl (Dec 8, 2011)

*"To some extent, the solvent does work as a carrier, changing the viscosity of the oil. Thinner viscosities of anything will penetrate more deeply. "*

Jay…. Simply not true. The oil disolves in the solvent just as sugar disolves in water, but neither the oil molecule nor the sugar molecule change. And the oil molecule, being quite big, won't go more than a few cells deep into the wood.

Pay heed to what Charles Neil just said.


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## Cosmicsniper (Oct 2, 2009)

Charles… There is a difference where you are making a living off wood (time is critical) and I am not. I wouldn't call oil an inferior finish. It suits a particular purpose, when specifically you don't want a film finish and you don't mind replenishing it. Heck, I think there might be a market for people with such furniture maintenance. I don't know…I always enjoyed the personal aspect of rubbing down an heirloom every now and then.

You mentioned modern day oils. Such oils, polymerized and/or with driers and/or resins shouldn't take two weeks to dry. Pure tung oil? Sure. But it still has some usefulness…just not in your line of work. Sorry, but just because things are modern doesn't always make them better…at least not philosophically. People have been trying I tell me for years that the NFL is better than MLB…sorry, but no.

Clint… Do you know how deep the pores of some woods run? Do you really think that oil, straight from the can, is at a viscosity thin enough to actually be at its smallest molecular level and provide all the penetration it can? When people pour coat after coat of oil into thirsty woods, where does it all go if not into the wood? You are a smart guy. You know the answers there.

I don't disagree with anything Charles said except that oil is an inferior finish. There might be better finishes for given applications, but such finishes don't become obsolete anymore than my Unisaw will once Gass has his say.


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## Cosmicsniper (Oct 2, 2009)

Btw, I use water-borne varnishes and modern lacquers. I understand the importance, speed, color-fastness, and protection of modern finishes. But I still like rubbing oil on a box. Nothing looks or feels as good.


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## Arminius (Dec 27, 2007)

Tung oil has significantly better water properties than BLO. I use tung oil on my canoe paddles, where an oil finish is much preferred over a film finish because it is much easier on the hands. It also does not yellow to the same degree, which is nice for maple paddles in particular.


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## wormil (Nov 19, 2011)

Arguing how deep the oil penetrates is pointless as it provides next to zero protection and is strictly for appearance. Wipe on a thin coat and wipe it off, done. It's like arguing which canoe is better in the Atlantic ocean during a hurricane.


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## Cosmicsniper (Oct 2, 2009)

You guys know that tung oil provides some water resistance, right? The more protection you want, the deeper it needs to go. It does cure in the cells, polymerizing in the wood with exposure to oxygen, so it becomes something different once it's in the wood through is cross-linking. The more cells affected, the more surface area is covered and the greater this protection will be. It's not great protection, but its better than nothing…and if replenished often, it keeps working.

Even if no protection, then it penetrates and brings out contrast and figure in the wood. The more it penetrates, the deeper and more beautiful it will be. This is why people spend time putting on lots of coats looking for maximum saturation. This isn't an urban myth. It does make a difference in the look of the wood. If you don't believe it, then test it yourself. Don't take our word for it. It's not hard to put differing levels of oil on figured wood and experiment. I have.

No, it does nothing to protect against abrasions and dents. But neither do film finishes on things like workbenches. Oil is better in that application because it is easy to repair, IMO.

Oil has its uses, whether on wood, baseball gloves, workbenches, boxes, or boat oars. It has a look and feel unlike any other finish. Wood is an much of a tactile thing as it is a visual thing. Oil and wax finishes cannot be replaced in that regard. I wanna touch wood on many objects…not plastic.

There is a reason that guys like Jewitt and Flexner dedicate chapters to oil finishing. They understand the value and realize that there are other aesthetics to wood finishing that go beyond our eyes. And I wouldn't buy any finishing book that fails to talk about those qualities.


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## Cosmicsniper (Oct 2, 2009)

Clint. Why not cite your sources with regard to the inability of oils to penetrate? That's contrary to most of what everybody believes, especially seeing as how many people actually categorize oils as a "penetrating finish."

BTW, Jewitt advocates heating up pure oils to 150 degrees F to facilitate faster penetration when applying them. It's a viscosity thing, much like the way oil becomes less viscous in a car engine. I live in Texas, that's almost not necessary for me.


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## oldnovice (Mar 7, 2009)

*Jewitt advocates heating up pure oils to 150 degrees F to facilitate faster penetration when applying them*

That sort of goes against the grain, no pun intended, more hazardous fumes, and more pentration?


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## ClintSearl (Dec 8, 2011)

Jay… it's chemistry. Your theory sounds plausible on its face, and that's what the marketers want you to believe, especially about multiple applications penetrating more deeply. Woodworkers tend to be pretty gullible when it comes to finishing. But the fact is as the first coat wets the first couple layers of wood cells and polymerizes, it creates a barrier to the further penetration of subsequent coats. So the second and later coats merely build up on the first coat, filling the tiny sufface voids and microscopically increasing the total film thickness with each application. The thicker the film, the richer the appearance, which you've mistaken for deeper penetration. Think about it.

Jewitt's recommendation doesn't increase penetration, but it does kickstart the polymerization process while making the woodworker feel good about what he's doing.


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## wormil (Nov 19, 2011)

*You guys know that tung oil provides some water resistance, right?*

And by "some" you mean about .1% right?


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## Arminius (Dec 27, 2007)

Rick,

What do you think a 10 year old walnut canoe paddle without an oil finish would look like?

Tung oil has a long history of marine use, and it holds up better than all but the very best marine varnishes.


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## lumberjoe (Mar 30, 2012)

The strength and moisture resistance of a finish is in it's build. Drying oils are a good finish for things that constantly need to be renewed (work benches, canoe paddles) but a poor choice for furniture. Arm-R-Seal pops grain just as good if not better than any straight up oil will.

I have heard heating oils will get them to penetrate faster - but who cares about penetration? The protection of your finish has nothing to do with how deep the finish penetrates; it has everything to do with how much you can build before you get a soft, gummy mess. You cannot build an oil finish. Dyes and stains are a different story, but we are talking about finishes here.


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## CharlesNeil (Oct 21, 2007)

I agree not all oils are inferior finishes, but BLO Vs Waterlox as an example, just no comparison !


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## Cosmicsniper (Oct 2, 2009)

Clint. Most of what you said is true, especially about people being gullible about finishing. I, however, am not one of those people. And the knee jerking swings the other way. Many guys like yourself are so anti-tradition that you fail to recognize that oils and shellac still have a place in our hobby/business. That's why I took exception to Charles' statement and why you always get blown up on LJ threads when you say BLO is only "good for starting fires."

And if you'll read up higher in the thread, I said exactly what you said about oil hardening after the first coat and somewhat preventing more absorption, which is why, like Joe, I prefer Flexner's method for oils…but sometimes I just like to rub on a few coats myself. Again, it's tactile enjoyment, but sometimes I'm happy with popping the figure with a single coat and covering with a film finish.

As far as coats of oil building up and making for deeper appearance, we'll just have to disagree on that. But I'd submit to you that oil just sitting on the surface looks much different than oil deep in the pores.

But you are assuming that one thin coat hits all the surface wood cells. No, that takes time and often times it just sits near the top or half way in the pores without really saturating…which is kinda your point, I guess. But it's for this reason that Flexner advocates flooding oil on the surface and letting it sit for 30 minutes. By flooding the work, you allow more oil to go into the wood before it starts to set up since the oil on top blocks the oxygen for a bit.

Simply put, if you apply with a rag in thin coats, you will need more coats to allow for complete coverage. It's not a given that there's no penetration after the first coat…it's just diminishing returns.

So, the objective is to keep the oil thin and oxygen free until it can get deeper in the wood. Again, this is why Jewitt says to heat the oil…to allow the oil to penetrate faster before it starts to set up. Oxygen polymerization happens regardless of temperature and heat polymerization requires about 500 degrees of it. The objective with heating, or thinning oil, is to change the viscosity of the mix to get oil deep in the wood before you the oxygen begins its hardening. Same can be said about finishes like shellac and poly.

Like you said, it's chemistry.


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## Cosmicsniper (Oct 2, 2009)

Charles…I thought that is what you were saying. You tend to be more clear on video…which has always been appreciated. 

Personally I see very little reason to use BLO (I dislike the look on light-colored wood), but when I have used it, it didnt take more than 2 or 3 days to cure…not two weeks. It is longer for pure tung oil, of course, but something polymerized like the Lee Valley stuff or the Tried and True variety (linseed oil in that case) doesnt take that long.

Of course something like Waterlox is a great finish, but that's also why we mix our own oil/varnish mixes. Even so, there is a difference in feel between something like Waterlox and just plain tung oil. I know that I prefer my guitar necks to be plain mahogany, with a little oil instead of having a film build-up. Taylor Guitars, among others, subscribes to this philosophy.

Plus, Waterlox and Arm-R-Seal aren't exactly cheap…that's a big consideration for guys like us…which I why we should give alternatives for various things we are looking for. I get bothered when people say that there's only ONE way to do something…because its usually the expensive way. I like Waterlox a lot, but I have no reason to pay extra for it when I can get the results I need by other means.

But if I want an oil look, more often than not I just grab a can of Watco Danish oil, chiefly because I can drive about 1 mile to pick some up and because the amount of varnish actually IN that product is very, very debatable. It gives the feel and look I'm often seeking and it dries in about 24 hours for me.


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## Cosmicsniper (Oct 2, 2009)

Joe…penetration matters because if it doesn't penetrate then the oil just sits atop the wood preventing more oil from being used. You get that gummy mess you are talking about well before you have enough oil in the wood to really do anything. You want the oil in the wood, not on the surface. That's where I agree with Clint…I just don't agree that this occurs because of the oil molecules being too big, which seems silly to me. I say it tends to sit atop the wood because of surface tension in its natural viscosity and because it will often start curing before it can really seep into the pores.


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## lumberjoe (Mar 30, 2012)

Thanks. My thought was more directed to the folks that insist on applying 6+ coats of oil/varnish or natural oil finishes. I think with the method I use 2 coats max is going to get all the absolution possible (complete saturation coats, not wiping it on). Also, maybe because you are in a much hotter climate but I have never seen danish oil cure that fast. I use danish oil a lot for the reasons you mentioned (it pops the grain well and is SUPER easy to apply with excellent results), but I always finish it after. If I give it anything less than 7 to 10 days, I get some bubbling/bleeding under my finish.


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## Cosmicsniper (Oct 2, 2009)

I agree with that, Joe. I think I voiced those same sentiments in another thread several weeks ago. But that is usually because people keep pouring it on thinking that a film coat can be built up. And it doesn't help that the can often say to do exactly that.

Once the wood is pretty, you move on. When I want the wood to speak for itself, which is always with woods like walnut, then I go with oil. If I need it durable, I top with a specific film finish. If not, I let it look pretty on a shelf, sometimes with a little shellac sealer, sometimes with wax, sometimes with both.

Those that argue that I can get the same result with Waterlox much faster, well, sometimes, but they also don't have my bank account.


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## wormil (Nov 19, 2011)

*What do you think a 10 year old walnut canoe paddle without an oil finish would look like?*

Too many variables to even comment. Whether it was really tung oil or a tung oil finish, whether it was used and how much, also walnut has moderate decay resistance.

*Tung oil has a long history of marine use, and it holds up better than all but the very best marine varnishes.*

BLO has a long history of use on gunstocks and people believe it holds up better than any other finish but it isn't true.


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## ClintSearl (Dec 8, 2011)

Jay…your rationalizations don't jibe with the physics and chemistry, but that's what makes religion. And that doesn't change the fact that BLO is only good for starting fires. Nyuk, nyuk


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## Billp (Nov 25, 2006)

I just used waterlox on a giant easel I made. It turned out fantastic and compared to regular tung oil this stuff is great.


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## roman (Sep 28, 2007)

The combinations and permutations of why tung oil works and doesn't is virtually endless due to the limitless perspectives of what its going to be applied to, and why


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## wormil (Nov 19, 2011)

I think it just gets made to be more complicated than it really is. It's fine to quote Flexner on flooding the surface but you can't ignore that he flat out tells you that it gives almost zero abrasion and water resistance. That's why wax is the traditional finish coat for oil. Folks seem to have an emotional investment on stuff like this when really it's just a tool, a means to an end. Use the appropriate tool for the job. Going on and on about how much oil is enough is pointless. You could soak that piece of wood in oil for a month and it will give no better appreciable protection than just wiping some across the surface. That isn't my opinion, it's a fact verified through long experience and scientific experimentation. Just to be clear, I'm not arguing that you shouldn't use oil but that you should understand and accept it's limitations just like you would any finish. You wouldn't use shellac on a bar top.


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