Pure Tung Oil ~ vs ~ Tung Oil "Finish"

With out the ingredients being listed I have read other articles which refer to Tung oil as a “finishing” oil but I think the labels cited as Tung oil finish may indicate the oil contains some “dryers” that make it dry or cure faster than plain tung oil. Other than that there is probably not much difference.
Others for instance, BLO boiled linseed oil is not boiled or heat treated it just has drier added. Regular linseed oil can take days to dry but BLO will dry overnight. Actually I don’t think it technically drys it cures and the oil oxidizes and the molecules bond and become solid.
I think that most of the problems people run into with oil finishes has to do with the drying time and the particular ambient temperature and humidity at the time they use it.

For example, Birchwood Case Tru-oil, it has been polyermized (heat treated) and has dryers added although they don’t tell you that. I can’t even find out if it is tung oil or linseed oil but it works great.

There is a good article in this months issue of Woodworkers Journal by Michael Dresdner who writes almost monthly on how to finish wood. This month he covers oil and wood.

-- Les B, Oregon

I think you’ve formed the crux of a really great thread here, John. Tung oil is one of the most confusing finishes out there, given that there is tung oil, and tung oil finish. There’s also a lot of confusion regarding the application of real pure tung oil. There are countless recipes for what cut to use.

I use the MilkPaint Pure Tung oil you show in the graphic. I also use their citrus solvent to cut it. I’m not all that into the green initiative, I just like the product. Anyway, I cut my tung oil 50/50. It soaks in nicely, dries relatively quickly and enhances the wood nicely. I pretty much never take it to completion as my final finish, preferring lacquer.

So that’s my tung oil story. Maybe we can turn this thread into a “here’s how I do it” thread.

-- Knowledge is not skill. Knowledge plus ten thousand times is skill. -- Shinichi Suzuki

Looking at the MSDS for the 5 tung oil varnish/finishes on the bottom, all have a lot of solvents (the lowest seems to be Watco, Waterlox is very high, at 75% solvent), which probably goes a long way to explaining why people find them so much easier to apply than pure tung oil (unless you thin it yourself like Rich does).
Waterlox, Old Master and Watco all seem to be a resin and tung oil mixture (plus the solvents, of course). I think Waterlox is a natural resin, the other two are alkyde resins. For Minwax and Formby’s it’s hard to tell if they have any actual tung oil and I’ve never used either.
Tung oil is my preferred finish. I like the polymerized stuff (Lee Valley sells it, but so do others). Dries a lot faster than pure tung oil, but the main thing I like about it is the ability to get a higher luster (although the higher the luster the more difficult the application becomes). I don’t topcoat it.

-- Jeremy, in the Acadian forests

Another good article on oil: https://www.canadianwoodworking.com/get-more/tung-oil-debunking-myths

After reading umpteen internet articles on Tung oil and Linseed oil I can understand the confusion. The biggest misconception is that these oils do not DRY they CURE or go through a process called polymerization where there is a chemical bonding that takes place when they are exposed to oxygen after being applied to the wood. That is what forms the scum on a partially full container too. What I didn’t know was 80+% of Tung oil comes from China….where everything else seems to come from LOL.
Solvents may cause them to soak into the wood easier but mostly just dilute the oil meaning more applications may be necessary to get the desired result. Some of them may go through a distillation process that helps them polymerize faster upon application. Adding “dryers” essentially heavy metals also speeds up the polymerization process.

Everything else is chemical wizardry of adding shellac and various hardeners, mostly to form a top finish.

From Canadian WoodWorking magazine: Myth: Tung Oil was invented by Homer Formsby in 1965 (Formsby’s Tung Oil Finish).
Nope. Tung oil has been around for thousands of years. There’s no doubt that Homer Formsby put tung oil on the map in North America in the late 1960s, when he started marketing his special finish. However, according to Bob Flexner in his book, “Flexner on Finishing”, Formsby’s concoction was really a wiping varnish made with (maybe) a little tung oil, a resin and a thinner.

-- Les B, Oregon

I use 100% tung oil, and I mix it 50% with tung oil, and 50% mineral spirits….It’s one of my favorite finishes to use….I generally put on a coat, let it dry good, and lightly sand it with 600 wet /dry paper….Add another coat, and repeat the process till I have about 3-4 coats on….I don’t like just tung oil finishes….100% tung oil for me..!!

-- " At my age, happy hour is a 2 hour nap".....!!