Tung oil toxic?

[Doug Kanter]

Just bought a bass guitar which does NOT have the high-gloss finish common to many electric guitars. It's got an oil-rubbed finish, including the neck. The manual suggests rubbing with tung oil occasionally. But, I seem to recall reading somewhere in the past few years that tung oil's not something you want to be in contact with for long periods of time. Obviously, this would be an issue for a salad bowl or cutting board, and not for an end table. But, anyone know about its safety level otherwise?

[J. Clarke]

Well, the Real Milk Paint Company claims that their Pure Tung Oil is FDA approved for food contact surfaces. Their MSDS says that a mild dermatitis is possible with prolonged contact.

Now, there are a lot of finishes that are called "tung oil" that have quite a lot besides tung oil in them.

[PDQ]

As OSHA advises "Don't drink the Tung Oil'.

--=20

PDQ

| recall reading somewhere in the past few years that tung oil's not = something=20 | you want to be in contact with for long periods of time. Obviously, = this=20 | would be an issue for a salad bowl or cutting board, and not for an = end=20 | table. But, anyone know about its safety level otherwise?=20 |=20 |

[fredfighter]

You can develop an allergy to almost anything.

Unless there were toxic materials added to it cured tung oil is non-toxic. It may have had driers added to it, or other oils, or it may have been an oil finish that didn't even have tung oil in it. I've never seen "Tung Oil" for sale that didn't say on the lable that it was 100% pure tung oil (contrary to what a pipular book on wood finishes) but have seen "Tung Oil Finishes" that said on the lable that they had other stuff in it.

But in general wood finsishes are all safe for handling after they have cured.

The only wood finish I would be concerned about handling after it was cured is Chinese Laquer. People who have been sensitized to poison ivy can get contact dermatitis from Chinese Laquer.

[Andy Dingley]

"One final note on this subject is to clarify the mistaken idea that [urushiol] lacquer is still toxic after drying. This is not so. Once polymerized it is no longer toxic. Even when lacquer breaks down with exposure to light, the degradation products are not toxic."

Marianne Webb, Lacquer: Technology and Conservation, § 1.7 p10, Butterworth Heinemann

For specifically "Chinese" lacquer then this was often filled with red vermillion (synthetic mercury sulphide). This is toxic, although not by contact dermatitis.

[JeffB]

Pure Tung Oil is not toxic, and neither are most wood finishes. The various solvents and driers added to finishes are why there are warnings about toxicity on the labels. In general, after wood finishes have _completely_ dried, they are non-toxic. For food surfaces or anything that a child would chew on, it's good to be extra cautious.

Of course, one could have allergic reactions to various ingredients in finishes, or to certain woods for that matter.

[Doug Kanter]

Awww crap. I was gonna use it, with garlic & thyme & pepper, as a marinade for grilled shrimp.

"PDQ" wrote in message news:GbW6e.3244$ [e-mail]... As OSHA advises "Don't drink the Tung Oil'.

[Doug Kanter]

OK....let's go in another direction, then. I won't hold anyone responsible for any disaster which might ensue from this. :-) I have a can of salad bowl finish in the cellar, from some company that starts with a "B". Whatever. Anyone wanna lay odds on how that might affect the BACK (not the fretboard) of a guitar neck, compared with tung oil?

[fredfighter]

OK, but you can be alergic to lots of stuff that's non-toxic, consider food alergies, for example. Contact dermatitis from exposure to lacquer (I thought my spelling looked funny) among Americans traveling in the Orient is well-documented. One particularly (in)famous example is the entourage that went with Nixon to China. Several people in the party had a reaction to the lacquered toilet seats.

Aparently it is generally not a problem for most Chinese, only to people who have previously had a reaction to poison ivy, (or poison oak or poison sumac I would suppose). Maybe an immunologist could explain it.

--=20

FF

[JeffB]

Behlen's Salad Bowl Finish is very similar to other oil finishs (Tung Oil Finish, Danish Oil Finish) that is a blend of a drying oil (probably linseed 'cause it's cheaper, but could have tung oil also), some resins (varnish) and a solvent (mineral spirits). As I remember, it has a moderate amount of resins and can build up a significant (for oil finishes) surface film by applying 3 coats.

I haven't made a guitar, but I would guess the normal finish would be a lacquer, which would be more durable than oil. But a good thing about renewing oil finishes, is you just put on another coat!

[George]

The Behlen's I had was tung-based.

[George]

Aparently it is generally not a problem for most Chinese, only to people who have previously had a reaction to poison ivy, (or poison oak or poison sumac I would suppose). Maybe an immunologist could explain it.

Or, you might read some of the information available at

have to have manufactured antibodies from a previous exposure to a similar substance. This does not mean you had to have experienced anything you'd recognize as a reaction.

[Andy Dingley]

You expect me to believe _Nixon_ ?

Good.

[fredfighter]

Would you REALLY want to see for yourself?