Home Forums Hunting & Shooting Gunsmithing Looking for some advice on a pure tung oil finish

Okay, to throw a wrench in this- how do you think the new formulations of thinner ("Safe thinner, I wouldn't call them solvents) affect all of this? In my experience, the original formulations of solvents/thinners were pretty predictable in how they reacted with "Tung oil" and other oils, but the new formulations, courtesy of our friends in California, are just a pain to work with and in my experience pretty unpredictable in how they react with finishes. Now, try to find the "original formulation" thinners these days...

The other thing is, what lots of guys are calling Tung Oil may or may not be actual Tung oil unless you can determine it's chemical content from the label, if the manufacturer is generous enough to supply one. Most of the cans marked Tung oil these days are filled with a synthetic material that is definitely not plant or animal based. This can also cause difficulty with predicting how materials will react with solvents and other materials called thinners...

Bob

Good point, re: California-driven solvents. I don't know the answer. Like I said, I don't thin finishes except to thin spar varnish with naptha for top coating. The jugs of mineral spirits, acetone, and denatured alcohol I keep around are mainly employed as de-greasers and for mopping up epoxy squeeze out on glue joints and to de-oil oily woods such as teak and rosewood before gluing them.

You have been surprisingly civil. Kudos!

It's almost like you are trying to be less prickish!

Just admit that you don't understand the concept of a practice board.

Hey guys, I happen to be a "California-driven solvent" so be nice. Just kidding. The tung oil I'm using, the tung oil on which I based this thread, is identified on the label as "100% Natural Unprocessed Tung Oil." At least that'show the guys at Wood River bottled it the fine fellows at Wood Craft sold it to me. So I m assuming that I've been using the pure stuff with absolutely no added crap (geez, I wish our gas was that way). After going through the exercise of this thread I've become convinced that solvents are not necessary and that its just as well to use the pure stuff as, how they say, "straight with no chaser." And that includes both tung and, as Gary wisened me up to, refined linseed oil bought from an art supply shop and not BLO from a big box DIY center.

Sadly by some standards, but really no big deal at all... there is absolutely NO guarantee there is ANY tung oil in 100% tung oil bottles. It is no different from linseed oil in any significant respect and is legally bottled as "100% tung oil" if it is an oil that acts just like tung oil. Not long ago the label had to say "tung oil FINISH" in order to be marked as pure tung oil, but that appears to have been dropped fairly recently.

I would sure love to know how they managed to make the oil without processing it

And there are few other uses for thinners in finishes...

Back in the day when good oil was hard to come by a little thinner in oil made it easier to apply. But these days, thickened oil should be tossed.

CA did some ridiculous things based on a couple major advances they claimed could be duplicated... they were very wrong. Last I looked their limit on VOCs is 3% and that started about 5 years ago. Just shortly before that it had been 30%. The 30% goal had been reached by major advances and with nothing else on the horizon they demanded an order of magnitude reduction. They have placed a ridiculous burden on the industry and so far, they have failed to make anything resembling a user-friendly finish. I suspect there are a significant number of folks using non-CA finishes there simply because they have to to stay viable.

Sitka deer - where do you get tung oil? You can do a google search for what I have. It's distributed by Wind Rover and the label also says Filtered, No Fillers, No Additives and No Dryers. I got it from Wood Craft, which is a store that services wood workers. It is thick like honey. Wood Craft also has a catalog and I don't know if they have outlets in Alaska. If I can't get the real deal there then I don't know where I can. Thanks again.

Woodworkers supply houses on line is where I buy mine. You won't find it in your local hardware store. The stuff they sell is tung oil finish- actually a diluted wiping varnish full of dryers, resins, and god knows what else, not bad stuff in its own right but not what we're addressing here, intended for Happy Harry Homeowners and their weekend projects. And there's a good chance it doesn't even contain tung oil- linseed oil has virtually identical properties and is used interchangeably in the industry depending solely upon economics.

Brownells lists the Old Master's brand at $45/quart(!!). "specs: 100% pure, natural tung oil without additives or driers, for beautiful, hand-rubbed, in-the-wood finishes" Between Old Master's and Brownells reputations it's a brand to look for anyway. A quart is A LOT. Most of it has probably gone bad in the can and I didn't pay anything like $45 at the time. But it gave the finish I was looking for, pure or not. Bought a can of BLO at the same time, the tung oil came out a little less glossy on the test boards but otherwise the same.

I buy oil from an art store usually. I do not request tung oil, just oil. A very good local paint supplier sells it but their smallest container is bigger than I like. I like a 4 ounce bottle.

The last thing you want is pure oil with the consistency of honey. It should be very thin and runny.

I add a commercial drier.

You sure like hearing yourself talk...you a BPD, NPD, ASTD or combination of all of them? No one listening to you in the Anchorage tattoo shop?

Angle those walls some, you are getting deep enough to worry about a cave-in.

Unless they lied about no driers/additives (could be) IIRC correctly the tung oil hardened a little faster than the BLO which I'm assuming had a drier added. But not enough difference to make an impression. Also IIRC Newell in his book said that a drier wasn't necessary for tung oil and you can get crackling problems.

Next, how many angels can dance on the head of a pin I suppose. Test board whatever you come up with, also the little practice applying the stuff couldn't hurt.

Thanks

Interesting about the thickness. I recently picked up a bottle of refined linseed oil from an art store. Is this the same stuff you are talking about?

Yes, that is the right stuff.

Not correct, driers are required for natural oils to cure, without exception. Those driers can be produced naturally in the oil by heating, but that process kicks off the curing very quickly and to do that with a commercial oil would require inhibitors. Those are the things that take bad oil and make it virtually useless, as in BLO.

There are no physical differences between linseed and tung in use. Tung does not dry faster than linseed when applied in exactly the same way with the same driers. Without carefully sourced oils it is impossible to know what you actually have in the bottle.

Crackling problems are easily produced with any oils. Start by using heavy coats; do not allow them to dry completely between coats; and use different brands or formulas to guarantee the coats dry at different rates. That will cause some layers to shrink faster than others and it will produce a very interesting alligator pattern, that still feels extremely smooth. Only problem with it is after a significant period of time the finish will cure completely at all levels and the cool pattern will disappear. Years down the road the finish may start to fail if there are old-style resins mixed with the oil. That will cause actual alligatoring of the finish and there will be surface cracks.

I've been happy with the results from Hope's pure tung oil on my last two projects, which were english walnut and curly maple. Found the stuff on Amazon. I may try rubbing in some Birchwood Casey stock wax on one of my test pieces to see if it shines up just a bit. I've had this oil for at least two years now and it's still as thin as the day I bought it. I store it in one of those collapsible water/wine bladder bottles and squeeze all the air out.