Tung Oil

[AlanN]

Good for baseball gloves, bad for mandolins http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[Dedian]

I think this has been discussed before (maybe not here but somewhere hehe), but the general concensus, unless someone more knowledgeable comes around, was that it wasn't as durable as varnish or lacquer. There's the neck, though, which some people sand to bare wood after finishing, and then put on a couple coats of tung oil since it's easier to play for those people, less sticky so to speak. I've yet to try that, but I might on my next.

[Bill Snyder]

Baseball gloves?

Tung oil is an excellent finish for wood such as furniture, but I have read on another site that it is definitely not a preferred finish on stringed instruments.
A similar finish that is used some is Tru-Oil. I believe it is polymerized linseed oil. Sold at gun shops for finishing gun stocks. I considered using this but went a more traditional route and used shellac.
The shellac is a nice looking finish, can be tinted, is very forgiving and also can be touched up later if the need arises.

[sunburst]

Tung oil has been used. It works Ok if well done, but not great.
I've seen mandolins finished in Tru-Oil that looked great.

[Magnus Geijer]

I found Tru-Oil to be an absolute miracle to work with. Dries fast, ridiculously easy to work with, and the results are great.
I used it on my #1 (below) and intend to use it on #2, #3 and #4 as well.

[sunburst]

Oh, and by the way. Tru-oil and comercially available tung oil finishes are technically oil varnishes. That means they are drying oils with resins and driers added.

The current interest and demand for varnish finished mandolins seems a little naive to me considering how many different things varnish can mean.

[John Ely]

I finished a mountain dulcimer I made in tung oil and was pleased. I don't think the finish is a tough as some of the others, but it was easy to apply, and I can repair it very simply.

[sunburst]

I don't think pure Tung oil would be considered a varnish, but I still may be wrong.
You're right. Pure tung oil is not a varnish. It is the only oil that will "dry" (that really means polymerize) completely in it's pure state. However, I didn't claim that it was a varnish. what I said was "...comercially available tung oil finishes are technically oil varnishes. That means they are drying oils with resins and driers added."
Perhaps I should have said "MOST commercially available...". Stuff like Watco and Waterlox.

[sunburst]

I've never read anything about Teak oil. My sources say tung is the only
drying oil that will actually dry, but I guess they were wrong.

A lot of my earlier experience came from furniture and cabinetry. Most
of the knowledge has been at least somewhat transferable in my experience.
One of the things that might be more important with instruments is the
desirability of keeping the finish thin. Also, instruments are meant to be
handled more than a lot of pieces of furniture and are commonly exposed to
more temperature extreems. That's why table top finishes are usually a poor
choice for instruments. The hardness makes them susceptible to checking with
temperature changes.

[WoodyMcKenzie]

You can see a photo at the url below of two instruments, one is finished with tung oil and the other is finished with Tru Oil. In this case, I believe the tung oil would be considered a varnish, since it is not pure. I bought "high gloss" Formby's brand from the local hardware store. I applied three very light coats. Should I choose to add more, I believe I could get a pretty good gloss. Tru Oil is about the easiest thing there is to use. It is linseed oil with "proprietary hardners".

From my experience, the best thing you can do is a lot of careful wood finish prep first and then do something to seal the wood. Once you start applying the finish, then unseen booboos can suddenly jump out at you if you haven't really been meticulous.

http://mckenziemusic.com/twopoint.htm

Woody

[sunburst]

You actually said,
"It is the only oil that will "dry" (that really means polymerize) completely in it's pure state."
Well alright then, I was wrong. Sorry.

[crawdad]

You know, you would probably benefit from trying a variety of finishes on some sanded and prepared scrap wood. The cost of the finish materials is not much, and you could gain experience in the application of each. Based on your experiments, you could decide which finish most appeals to you.

I've been working with the french polish for a while and I continue to practice on scrap, so when I hit the real instrument, I know what to expect. Finishing is a whole art in itself and its better to have some practive under your belt before you dive into a full bore instrument finishing.

[WoodyMcKenzie]

treidm asked:
# #"Do you feel the tru-oil darkens or changes color of the wood any or is pretty much neutral like Tung?"

Initially, comparing the two both on redwood and maple samples, the Tru Oil shows a slightly "richer" appearance, but this is a very small difference. From my reading, linseed oil will yellow with age. But age is relative here, since there are violins that are centuries old that have been finished with varnishes using linseed oil fused with pine resin and they are still quite beautiful, with the yellowing that may have occurred really adding to their beauty. On both of the mandolins I have built and finished, I used a mineral ground sealer coat which made the instrument look like it had a plaster coat (it did, sort of!) before I applied a substance called rosin oil, which clears both the mineral coat and the wood. I adapted my method from the late David Rubio ( search for rubioviolin). For finishing the octave mandolin I just built, I used tung oil and nothing else. It looks more plain, but really has a nice natural look and still feels more like a piece of wood.

So, my experience is limited to violin oil varnishes and drying oils on mandolins. After staring at wood and wood covered with different finishes a lot, I must say that I find #the look of an instrument's unstained wood through a varnish that has color much preferable to stained wood covered by a clear and colorless hard coat. A lacquer finished instrument looks like it has been plastic coated to me. One way to think of it is to compare it to looking at the world through colored glasses vs. looking at the world that has been painted to suit your taste. It's really more complicated than that even. As the incident light #changes angles, then the look of the wood changes, especially if the wood has been made to accept light (not pigmented) and the varnish coat has color-- the light will travel through more varnish at an angle so this will make the wood appear to have more color, or less color when the incident light is perpendicular. The instrument can really change its appearance when turned in the light. #Also, the instrument will look different #(and nicer I think)
in natural sunlight.

Well, anyway, all this can quickly become more complicated and time consuming and also very nitpicky and frustratingingly #easy to mess up than most people care to be encumbered with. Maybe that's why lots of folks just spray on lacquer...

Woody

[UncleNorm]

Interesting dialogue. I like the suggestion of trying various finishes on scraps of wood. Most of the concerns talked about are centered on "looks" and "protection". What about the effect on sound? Oils penetrate and would likely DULL sound. Maybe try the finishes on scraps of the same wood, same sized pieces (as in xylophone blocks) to see what changes you hear/make to sound. Traditional Violin makers go to extremes to seal the wood before applying colour or the final finish. If you have access to a good library, check out Sacconi's book, "The secrets of Stradivari" on varnish. Good luck.

[Ed Ashley]

I think the trick on the oils (like Tru-Oil) is to get them on and then rubbed off quickly, successive very thin coatings, so as to prevent much penetration.

[WoodyMcKenzie]

I believe the effect of #oils or other protective coatings on the tone of instruments is minimal *if* the wood is properly sealed and the coating is kept thin. When I tung oiled my locust xylophone bars, I applied as thick a coating as I could the first time and then came back the next day and coated them again. I then had to fine tune them, with most of them very slightly increasing in pitch. #I attribute this to the treatment stiffening the wood as the oil dries and hardens. That may not be a bad thing, depending on what kind of sound you are going for.

With violins, there is a very noticeable difference between the sound of an unvarnished instrument strung up "in the white" and the final finished instrument. #Not sure it's worth trying to put into words, except to maybe generalize and say that the effect of varnishing on tone or sound is to maybe "constrain" or "focus" the sound. It also might #"dull" the sound as Norman mentioned in the previous post, but I believe that this may be a temporary condition that improves as the varnish cures. Interesting to note that drying oils actually take on weight as they cure by oxidation.

I would be curious to know if any of you can generalize about the difference in volume and tone of your instruments between "in the white" and newly finished, or do you even string up your mandolins before you finish them?

Woody

[Bandersnatch Reverb]

This is sort of an older thread, but I was reading back, and have some good deal of experience with oils, varnishes and poly finishes.

First, it ought to be known that the tung oil you get at places like Home Depot are polyurethane enhanced oils. Ditto for Tru-Oil. Of the two (and I like neither) I'd pick Tru-Oil as it seems to leave a harder finish, and can be buffed to a gloss more easily. Tru-Oil is amber, and will add that color to your work, although in thin applications it ought not color it too much. Tru-Oil in one light coat will pretty much seal the wood if left to completely dry - which takes a while, much longer than "dry to touch" time. I'd say more like a week or 10 days to really cure up for the additional coats not to melt in and further penetrate. Thin is better on all coats. Tru-Oil can get lumpy and clumpy if you're not careful and accidentally get it on thick. I cant recall what the thinner is, but it can be thinned to make it apply more easily, as it does begin to "set" pretty rapidly.

Regular "boiled" linseed oil is out of the question. The finish is not hard, and it takes forever to dry. Lin-Speed is about the same as Tru-Oil.

Pure tung oil is wonderful to work with, smells great and leaves a pretty hard and durable finish. I have rifle stocks and handgun grips that I finished in pure tung oil, and the finish has not degraded with field use or sweaty palms at the range. If abraded, it is quite easily "restored" with additional coats. It can be built up to a thickness that can be buffed to a gloss, but... it requires a VERY light touch to buff. Think of the most fragile laquer application, its about like that... dont get heavy handed! If you do, no biggie, you have to build the finish back up again. Here's the thing with pure tung oil - it takes near forever to dry, and driers totally alter the toughness of the finish, softening it quite a lot. So if you want tung oil, be prepared to go for days and days between coats, and allow weeks or longer for the final cure. Last rifle stock I finished (1957 B.S.A. Martini Olympic target rifle), the finishing took the better part of a long summer, going at two coats a week, with a full month for final setup before buffing. I buffed it by hand, not on a wheel but it was full gloss when done. Pure tung oil is very very light amber. It might colorize the lightest spruce tops if left natural, but I cant see it doing much on any dyed finish.

Having said all that - I've never finished a mandolin, but it seems there ought to be easier to use finishes out there beside Tru-Oil or pure tung oil. The little I read in the Stew-Mac catalogs suggests this at least.

[Varmit]

I use a wash coat or very fine sprayed layer of shellac to seal the wood some and stop the oil from soaking in so much ,,oils like tru-oil will gloss up much faster this way
David

[jc2]

I think that linseed oil and sunflower oil also polymerize completely and harden. I haven't used them on instruments, but if you know that they don't harden, please tell me so I can stop using them on cabinets.

If your goal is to stop the oil from penetrating the wood and softening and deadening it, a violinmaker/researcher friend applies a "ground" first of mineral spirits mixed with very finely powdered dolomite. He has some interesting photomicrographs of wood cross sections prepared both ways which show almost no penetration of the wood by varnish after ground, making a very thin layer right on the surface. The dolomite may have finely powdered silica mixed with it. He said their ideal source was the White Sands govt. property they couldn't get onto so they used wind drift from the roads around the area.(his story)

[Bandersnatch Reverb]

Linseed oil does harden to some extent.

On a rifle - where walnut varieties have been smoothly sanded and many coats of linseed oil applied, it works well, as the finish is infinately renewable.

On a cabinet - where multiple coats can give a deep luster which is occasionally renewed keep the cabinet looking great, linseed or other oils do nicely.

Linseed oil is terrible on flooring. Linseed oil ain't so great where somebody might set a dripping cold beverage container.

Never have done this, but I cant imagine the sweat and grime of mandolin playing (or guitar playing) being real good for a linseed oil finish. Tru-Oil would do better. Pure tung oil even better.