Differences Between Tung Oil and Watco?

I am having a very hard time finding Watco locally, I am trying to avoid ordering it on-line, tough times let’s say. I have a quart of Tung Oil and after reading enough stuff on-line my eyes are burning and my brain is fried. So what is the skinny on the difference between the two? From what I’ve read Watco is more of a finishing oil and Tung builds up layer of protection with several coats with a lot of buffing, yup, elbow grease.

Anyone care to educate this dumbass? I have always used spar on my gunwales but this is a customers gunwales I’m working on and am trying to make sense of this all. I think I lost it when one thread went into the properties and polymers of the mix. Any suggestions in laymen’s terms would be greatly appreciated.


Like tung

– Last Updated: Mar-27-12 8:01 PM EST –

I've used both, but prefer tung. There's plenty of room for reasonable folks to differ, though. Guideboatguy uses a linseed oil mixture and it looks nice also.
I got a Bell years ago and they recommended Watco, so that's what I've used on that boat. I think the Watco penetrates better. It takes longer before you can recoat with Watco and if you rush it, it takes quite a while before it looses its slight tackiness. I've never gotten enough coats on it to really fill the grain.
I've thinned tung oil for the first few coats and used it straight from the bottle since. Eventually it will fill the grain of the wood and gives a nice satin patina, almost like a varnish. It darkens a bit with age.
I haven't found tung to be particularly labor intensive. I usually wipe it on with a cotton rag and wipe off the excess within a half hour. If I do that in the morning, I can do it again at dusk and, unlike the Watco, it will have no tackiness and be ready to paddle the next morning. If the boat slips a bit on the roof rack and you have acrylic carpet for padding on the rack, it will rub off the top layers in 1500 miles or so, but it is still waterproof. Every five or six coats I lightly sand it with 220 using a block and oil again. Been doing that on my 17 year old Blackhawks all along and they look really nice to my eye.
Do make sure to clean up any drips on the hull right away. Tung is pretty tough stuff once it dries and if you don't get it up right away its a real bear to remove drip marks.
Hope this helps...
PS: I think it takes at least six coats of either to get raw wood water-resistant. I'm working on a new sliding seat now and in the course of that little project have been talking with some folks from WCHA. (Wooden Canoe Heritage Assoc) The guy I'm talking with (who knows a thing or two about building wooden canoes, to say the least) is suggesting doing an initial coat or two of spar varnish thinned 50% as a sealer. Perhaps that will mean fewer coats to initial waterproofing and grain fill. We'll see. Live and learn.

We use tung on all our wood gunnels
and like it.

We do them once a year or every other year.

It creates a nice flat luster finish and seems to repel water nicely. Sometimes it will take up to three coats, with buffing between coats.

Can’t help you on the watco, since we have never used it.

Jack L

tastes better fried in tung oil than in Watco, at least to me.


I just like saying “Tung Nuts”.

– Last Updated: Mar-27-12 8:16 PM EST –

It's worth using for that reason alone.

If it's the "pure" variety, though, you should thin it with turpentine or mineral spirits. Otherwise, it takes forever to dry. Most tung oil finishes you'll find are already modified with solvents and metallic driers added just like Watco and other oil finishes.

In the end, it won't make a whole lot of difference which oil finish you use since they're all basically variations on the same age-old formula, each with its own unique sales pitch. They all form a very thin barrier that needs regular maintenance.

I use Watco Danish oil quite often. Although it does not last as long as Tung oil it’s easy to apply and dries without being too sticky. Can be found at Home Depot last time I checked. Having a real hard time finding pure tong oil anyway.


Can’t get Watco Exterior finish either
I tried ordering it on line and no one would ship it to RI. I did get some Marine tung oil from West Marine, but I didn’t like it. I applied a few light coats, but once I got the boat back in the water, the gunwales felt slimey. Maybe I needed to buff it more.

I started out appling too much Watco causing drips and slow drying. Many lite coats work much better. I now use a green scrubby to apply it as someone suggested. This smothes and applies in one coat.You need to apply it several times a year and yes new wood needs a lot at first. I love the smell which adds pleasure to the job.


tung oil has to be really worked in with
a scotchbrite pad… And it has to be multiple coats.

Just wiping it on does nothing.

Seems that varnish and paint formulations are changing with new VOC laws in some states. In Maine we can no longer buy oil based paint. And the new formulations will not penetrate the older oil based stains…which for exterior stains leave a layer of paraffin for protection on the surface. My husband has been scrubbing rough sawn cedar for a year to restain the house.

Watco is Dapper Dan for your gunnels
, and I like like odor of my wood treatment; the pleasing smell is half the point

Pure tung oil cures fairly quickly…
…as in 24 hours at room temp. Thinning isn’t necessary other than to promote penetration, but the difference is negligible. OTOH, raw linseed oil can take weeks or months to cure, which is why it’s rarely used as a wood finish. With ANY pure oil finish and with most varnishes, if you try to rush it and re-apply before the first coat is cured, it will dramatically extend the cure time. It requires oxygen to cure and if you cut off the oxygen supply to the first layer by re-coating too soon, it can’t cure normally. The more coats you add, the worse the problem gets.

Multiple coats, yes…
…but the only advantage off applying it with an abrasive like Scotchbrite or wet/dry sandpaper is that you get a smoother finish; it does nothing to promote penetration. Short of soaking the wood in oil, you’re never going to get more than a few thousandths of an inch of penetration, except on end grain. This is easy to test: Finish a piece of wood, then take a plane set for a very fine shaving (.001"-.003") and see how many strokes it takes to get down to bare wood. You’ll probably be surprised.

Tung oil vs. "Tung Oil Finish"
Most of the “tung oil finish” products on the market are actually thinned varnishes that contain little or no tung oil at all. They’re actually more like Watco than they are like pure tung oil. Unless the label says 100% tung oil, you really don’t know what’s in the can/bottle. If you can’t get Watco and you want something similar, Formby’s and Minwax “tung oil finish” products are pretty similar, though probably a bit thicker.

Behlen pure tung oil.
Recommendation printed on the label is to thin 4 parts solvent to 1 part oil.

The can I’ve had for years is of thick viscosity, so I thinned it more or less as directed, applied one coat to mahogany trim in my shop last week when we were experiencing near summer temps, and it still took four days to cure hard.

Old stock?

I wouldn’t a pegged our…
…current inquisitor into the finer points of manufactured celluant finishes as a Dapper Dan man, Dellwood.

No, based upon an extensive history involvin’ slings-n-arrows-n-whatnots which have befallen the shattered grain of his existence, as well as appraisin’ the somewhat dilapidated and rather creaky exterior within which he comports, I’d suspect him to likely gravitate towards be’n a Ben Gay fella.

Now, knowin’ how do-it-yer-self’n thrift-conscientious our oft-luxated Penacook bantam is, it suprises me, considerin’ his current inquiry, that he has not sought solution in that elixir of wood finishing that our sometime resident sage Randall had educated this pixel-poppin’ populace about per past postings. That is, the one-third/one-third/one-third blending (or variations in percentages, thereof, depending upon your Mad Scientist McCrea Theorems In Formulations and Function experimentation results) of boiled linseed oil, turpentine, and marine spar varnish, sometimes referred to as “Arkay Oil.”

Most “tung oil” is actually a thinned wiping varnish, just like Watco “oil finish” is actually a thin varnish.

I expect this accounts for the different experiences people have with cure times for tung oil. The varnish mixtures cure in hours. Pure oil takes days.

Are you using my gunwale treatment?
Because I too am a Watco-man…Frequent light coats of Watco Teak Oil; remember this one simple precept and your time will not have been ill-spent.

A geographical oddity …
… two weeks from everywhere

And I apply it with a hair net

Minwax Tung Oil Finish
is what I ended up with. I wasn’t familiar with the other brands on the shelf. I guess the thing to do is just try it on a left over piece and see how it goes. Looks like I’ll be waiting for some warmer weather though as I don’t think it will work as well in an unheated shed in these damp and cooler temps we’re having now. Thanks for all the answers!