Tung oil for pens?

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LabTrnr

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True Tung oil has a very long cure time, it could take weeks to months to fully cure. Even once cured it still wouldn't hold up to the daily use and abuse a pen gets.
 

GBusardo

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BLO takes a long time to cure too, but it works with CA. Maybe pure tung oil will work also. Be carefull though, most tung oil finishes do not have any tung oil in them.
 

leehljp

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I have used pure and polymerized tung oil on flat wood followed by urethane and it does great. I have a small end table beside my easy chair that was finished with three coats of TO followed by 3 coats of urethane. It has withstood 18 years of hot and cold glasses and cups along with spills and the finish is the same today as it was then. No water stains or abrasions visible. Semi-gloss shine still there. I haven't tried this on a pen yet but I sure have thought about it.

AS to the curing time for TO - if applied like BLO is, the heat and friction should help speed up the curing/catalyzing. The advantage of BLO is its reaction to and with CA. Not sure how TO will do with CA.

TO alone will take some work to build up layers. Another thing to watch for is that while TO will pop the grain just fine, will give light woods like holly an unwanted amberish color (and BLO does this too).
 

redfishsc

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I remember specifically someone asking Russ if Tung oil worked with CA.

If I recall correctly, he said "no".

The BLO does not contribute hardly anything to the CA finish, rather it is used as a catalyst to harden the CA and a lube to smooth it out.



Now, Tung Oil is my FAVORITE oil finish. I've put pure Tung oil on lots of things, but mostly smaller items like jewelry boxes that do not get handled a lot.


Tung is just like any oil finish: not chemically durable, soft, and does not build a layer of protection on the wood like Waterlox (which is a tung-based urethane) or lacquer.


That being said, if you have a customer who wants a "raw wood" feel on his pens, I'd suspect a few good rubs of tung oil, 24 hours apart, with the final coat cured out for a week before a nice wax job, you'd have a very pretty pen. The amount of time needed for the actual labor wouldn't be a whole lot, but the time spent curing would really test my patience for a pen!
 

leehljp

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The BLO does not contribute hardly anything to the CA finish, rather it is used as a catalyst to harden the CA and a lube to smooth it out.

Tung is just like any oil finish: not chemically durable, soft, and does not build a layer of protection on the wood like Waterlox (which is a tung-based urethane) or lacquer.
Matt,

I have to disagree with both of the statements above:

BLO does pop the grain and add a nice umber/warmth appearance to some woods, that if left to straight CA, would be obvious in its lack of warmth.

As to TO being like any other oil finish and not chemically durable, soft . . . I have read that from a couple of other people too. However, my personal experience has been the opposite of that. I have also read the EXACT opposite from others - it is as though we are talking and using two totally different finishes.

A friend in Australia joined in a discussion on this a few years ago and offered the following illustration. He put coated (totally soaked) some small towels in different finishes, including TO. He let them stay on a clothes line for a week. Then he placed them in a tub of water for a week. The TO was the only one that did not break down.

I have always heard that TO was the only natural oil finish to totally withstand water stains from glasses. My parents used to say this also and we never had water stains on our tables even back when we did not have coasters.

Here is a link on TO that states the durability of TO, which matches my experiences from childhood with it as a finish:

http://www.sutherlandwelles.com/tungoil.htm

"The first record of Tung Oil appears in the writings of Confucius dated about 400 B.C. . Even then, the Chinese recognized the amazing qualities of Tung Oil. Throughout their history, the Chinese have used Tung Oil to waterproof the masts and sails of junks (boats), to finish furniture of royal families and according to legend, to seal the Great Wall! When Marco Polo returned from China, he brought tales of the wonderful "China Wood Oil". But Tung oil was unable to capture the attention of the West until this century.
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A Polymerized Tung Oil finish is hard yet flexible, waterproof and impervious to alcohol and many food acids. Polymerized Tung oil as a penetrating oil allows wood to continue its aging process and to develop its patina. The wood's rich color and grain are enhanced by the natural ambering (coloring) of Polymerized Tung oil over time. Any sign of wear disappears when a thin "maintenance" coat of oil is rubbed in. The maintenance coats, rather than cause a build-up, actually improve the patina as they protect and preserve the wood. A floor, a piece of furniture, or any other wood object finished and maintained with Polymerized Tung Oil will never have to be stripped again. The finish will become more beautiful with time."


For me on my end table, I did put three coats of poly on top, a week after applying three coats of the TO. I never had that kind of finish with straight Poly or straight TO itself.

Sam Maloof's special mix of finish is 1/3 TO, Poly and BLO. But that was not formulated for pens.
 

RussFairfield

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I will have to hedge my statement that Tung Oil doesn't work, because not all pure Tung Oil is equal regardless of what it says on the label.

I had a conversation on this topic with Michael Dresdner, the finishing expert, several years ago. His opionion was that it was the drying agents that were added to the Raw Linseed Oil to turn it into what we know as Boiled Linseed Oil (BLO) that accelerated the cure of the CA glue; and that this faster curing created heat that made for a faster polymerization of the BLO. My experience with the BLO/CA finish makes me believe that he was correct.

Times have changed, and not all "100% pure" Tung Oil is pure. Regardless what it says on the label, some of these "pure" Tung Oils contain drying agents to make them dry faster, and some of them are further procecessed to start the polymerization process before the oil is put in the can and shipped. These Tung Oils can be used as a substitute for the BLO. There is no way of knpwing which Pure Tung Oil is really pure, and the manufacturers aren't willing to tell us. It could be that there is no longer such a thing as a "pure" Tung Oil.

If you have the Tung Oil and want to try it, the worst that can happen is that you will have to remove it and start overe. I just use the BLO because it works, and all BLO is the same.
 
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DCBluesman

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First off, I am not contradicting or arguing with anyone. These are just a collection of experiences and some applied chemistry knowledge.

Pure tung oil comes from the seed of the nut of the tung or chinawood tree (Aleurites fordii Hemsl). The tree is native to China, Vietnam and Myanmar (ne Burma). The tree has been successfully introduced to the Gulf coast of the United States as a source of tung oil and is considered an invasive tree in Florida.

Even without polymerization, tung oil is a drying oil and will produce a hard, water-resistant, mildly amber finish. The amber color does not darken noticeably with age like linseed oil (from the flax seed) does. Pure tung oil is also subject to going rancid, so fresh tung oil needs to be from a known source and has a limited shelf life.

Tung oil is polymerized though the application of heat or chemicals. The polymerization allows for the creation of a more penetrating liquid. This is, of course, advantageous when using tung oil as a wood finish.

Tung oil finish has become a generic term for any finish which creates the "wet look" that a high quality pure tung oil finish yields. In most cases, there is no oil from the tung tree in the finishes.

Overall, tung oil is a slower finishing process. Although it is a drying oil, it still takes longer to dry than solvent- or water-borne plastics (lacquer, polyurethane, etc.). That being said, once fulled dried, tung oil can buff to a brilliant sheen and highly protective finish.
 

leehljp

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Lou, you are a diplomat! :)

What you and Russ posted regarding TO as a finish is also my experience and understanding. I had a very difficult time finding TO here in Japan. Then about 3 years ago, I ran across an article that had a reference to China Tree Oil made from the tung nut. I had seen but never used a common finish that had the characters of China + Tree + Oil, but being slow of mind, didn't connect it. The China tree oil here is much less umber in color - almost clear, so I never gave it a thought.

For 20 years, I have been seeing China Tree Oil (in Japanese characters of course) and didn't know what it was. Even Japanese explaining it to me did not refer to it as "tung nut oil."

DRYERS:
Russ brought up a term that is greatly misunderstood - Dryers and more specifically "Japan Dryers". In some fine finish stores, "Japan Dryers" can be purchased for the purpose that Russ referred to. However, "Japan Dryers" are not Japanese and have not been available here, unless a few places have begun to import them recently.

The US (and maybe Europe) fine paint/finish industries observed that the Japanese paint/finish industry centered around lacquer and derivatives. The finishes here were well known for their rapid setting and curing. The US/(Europe?) developed dryers to speed up the drying process and called it "Japan Dryers" that they did not use over here.
 

redfishsc

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I didn't know where Japan dryers got their name, thanks Hank.


What I meant in my statement about BLO not adding anything to the CA finish was in terms of durability or hardness (which are the two items that Tung has over BLO). Some folks think that BLO somehow hybridizes the CA into a really durable finish (it's difficult to improve on the hardness of regular CA anyhow).


As far as Tung being soft, I'm talking in terms of comparing it to CA. I've used enough 100% Tung (Behelen) to know it makes a superior oil finish to "danish oil" and BLO, but one thing it does not do is build up a noticably thick layer like lacquer, urethane, or CA (polymerized tung being the exception).
 

bradh

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What I meant in my statement about BLO not adding anything to the CA finish was in terms of durability or hardness (which are the two items that Tung has over BLO). Some folks think that BLO somehow hybridizes the CA into a really durable finish (it's difficult to improve on the hardness of regular CA anyhow).
Below is a submission made to the Yahoo pen turners forum several years back. It is very technical, but Henk is a chemist who understands this stuff better that I ever will:

BLO / CA Chemistry
Linseed oil, a (semi-)drying oil, will polymerize under influence of oxygen/radicals. The double bonds in the linseed oil fatty acids 'connect' to each other, and because there are three fatty acids in each molecule, this creates a 3D network of polymer molecules, i.e. a resinous 'plastic'.
BLO, a linseed oil with catalysts added, polymerizes a lot faster, but yields basically the same resin. Since (B)LO is yellow to begin with, the resin also is. Due to light influence over time, LO resin will yellow some more. Can't think of anything that will turn it black, other than fire, sulfuric acid, or maybe a wrong catalyst (or way too much of it).
That being said, the CA/BLO resin is a completely different resin. In BLO, the cross-links occur between individual fatty acid residues, so the triglycerides (the BLO molecules) are attached to one another, creating a true resin. In CA, the cyanoacrylate molecules attach to one another, creating a polyacrylate linear polymer. In CA/BLO, the cyanoacrylate monomers and oligomers (short chains of CA molecules in the process of becoming a polyacrylate) basically act similarly to the catalysts in BLO, in that they accelerate the activation of the fatty acid double bonds. In contrast to the normal BLO reaction though, the CA mono/oligomers actually attach to a fatty acid, then attach another CA or BLO molecule on the other end of their chain. You basically get a resin in which CA mono/oligomers form bridges between the LO molecules, so you get a copolymer resin.
Interestingly, it should be possible to control the average CA chain length in the bridges, thereby influencing the properties of the resin. Whether that can be done by time control, temperature, additives, or choice of CA (thin, thick; methyl, ethyl, octyl, etc), I have no idea. Don't even know whether any research on CA copolymers exists. Haven't found it yet...

Cheers
Henk
====================Heisenberg was right!=========================
| Dr. Henk J.M. Verhaar | |
| Principal | e-mail: hverhaar@environcorp.nl |
| Ecotoxicology specialist | home: henk@stichtsend.xs4all.nl |
| ENVIRON Netherlands B.V. | |
| Zeisteroever 17 | phone: +31 30 698 6218 |
| NL-3704 GB Zeist | fax: +31 30 698 6239 |
| the Netherlands | |
====================Uncertainty happens!==========================

Basically Henk is stating that BLO will bond to the CA creating a new material with some properties of each of its components.
When we put layers of BLO or CA down and follow with another layer before the first has dryed, we get a molecular bond of the two finishes.
 
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