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Syne7

Finishing a Violin in "the white" w/Tung Oil

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quote:


Originally posted by:
JCHungerpiller

David,

please explain the spreading on paper toweling? Does this correlate with "seeping" into wood? Does application technique play a role in penetration? I would assume that "bad" oil that dried very slowly and contained the above "contaminants" that just sat around "wet" would penetrate more and saturate the wood. Is this a correct assumption?

Cold pressed, washed, otherwise untreated linseed oil (which I think is what you mentioned) is low viscosity and doesn't dry very fast. At least I haven't seen any that does. It would have a lot of time to penetrate into the wood and move around, particularly the top.

The surface could be dried fairly quickly with exposure to UV, but UV wouldn't penetrate well to sufficient depth to do much below the surface, the refractive index of straight linseed oil being on the low side for good UV pentration. There's also an oxygen availability problem. So you have un-polymerized oil in the wood for who knows how long, continuing to move around (penetrate even deeper), damp the sound and add mass versus something which stays near the surface.

People I've talked to who attended Mittenwald 20-50 years ago observed different techniques, but a common one was to saturate the wood with oil until it "wouldn't take any more", let it dry (of course, only the surface was dry), re-apply etc.

Even with a sparse application, I think penetration due to end grain (flames and large portions of the top) would be too great to dry thoroughly in a short time. As this absorbed oil changes state, I'd think at the very least that it would contribute to an unstable sounding new instrument which continues to change over a long period of time as the internal oil dries. The customer buys a violin that sounds a certain way, and a couple of years later it sounds very different.

Treated linseed oil or other oils might be another matter entirely.

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David,

Though treated linseed oils would cure faster, all linseed oil curing depends on exposure to heat and light [uV]. Curing times for saturated wood would be 30 - 45 days at a minimum.

If the oil is applied hot...100C or so...then that time would be days not weeks.

On we go,

Joe

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quote:


Originally posted by:
JCHungerpiller

So what is the best school? IF you could go anywhere....where would you go....or would you go anywhere? Would you pursue an apprenticeship(s)?

Thanks JC

School followed by work experience in a major shop is the route taken by a high proportion of successful makers.

I won't recommend one school over another. Schools change as the teachers change, and much depends on the student. There are some I wouldn't recommend, but ain't sayin' here.

Several years ago when we did an Oberlin program featuring a week of presentations from VSA multiple tone award winners, a disproportionate number of them had gone through the Chicago school.

quote:


Originally posted by:
joerobson

Though treated linseed oils would cure faster, all linseed oil curing depends on exposure to heat and light [uV].

Do we want to add oxygen to that? Can't get the stuff to dry very quickly in a closed bottle, or one filled with inert gas.

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I don't know this as a fact but it would seem logical to me that "hot" linseed oil would have a lower viscosity and thus, a faster flow rate into the wood. Perhaps it would dry faster but wouldn't it penetrate more deeply.*

*No word play allowed by order of the Knights of Wee.

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Hi all:

I wanted to thank everyone for the links and help for finding pure tung oil. I think leevalley.com has what I want plus they also have the veneer saw I've owned in the past.

I switched browsers in hopes that my paragraphs won't be stripped out so let's see what happens.

I also found the profile manager and changed to html editor, hope that works.

gtm

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Hi all,

Here is my silly question: " What is wrong to use "the regular type of " varnish? " (The underline reason of

trying something new (unproven) must be something wrong if you do it the usual way)

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quote:


Originally posted by:
yuen

Hi all,

Here is my silly question: " What is wrong to use "the regular type of " varnish? " (The underline reason of trying something new (unproven) must be something wrong if you do it the usual way)

The only silly questions are those not asked.

Most assuredly in my case it's (tung oil) a finish that I have had the the best and most predictable results though not on a violin. Who is to say why varnish became the standard, a guess was it was available and tung was not until the trade routes were established but by then the master builders were committed and this was what the knew worked.

I do have hardness concerns in that tung may not have the same elastic properties of varnish. I can't imagine a sound board coated with rubber cement would project very far, since tung does not get brittle as varnish it may adversely affect the sound projection. It would be of interest to know the hardness of each and the penetration depths. I suspect tung will have less penetration unless it's allowed to stand in it's oil form for longer than the 5-15 minutes suggested. Whether this is a good thing is unknown, once the rubbing has achieved the plastic state then I can't see it migrating any deeper. Subsequent coats only enhance the seemingly depth/thickness perception more akin to that of a hologram that is not as noticeable in varnish.

I would also say that the satin finish may give an older look to a newly finished instrument if that's desirable. The other advantage is should if the instrument is scratched repairs don't require anything more than a single drop well rubbed rather than a trip to a highly qualified refinisher. You will never see a difference from a repair blended in, just one of those many qualities.

I am not prepared to endorse it on a valuable instrument until more information is known and perhaps some sophisticated sound wave analysis is done to ensure harmonics are not lost. From observations I would say varnish is more brittle which may be an asset in sound / tonal projection, for me it's an experiment I've wanted to try without running the risk of spoiling something that has a huge investment.in time or initial expense. I can purchase an unfinished violin for $95-$300, pull the top and thin to an acceptable level, sand inside and out, re-glue and finish.

Does anyone have a time estimate needed for varnishing?

Cheers,

gtm

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gtm,

Since it is hobby project for insight, why not put on the fingerboard first. Then play against another violin before any finish is used. Put on the first coat of Tung, dry, play. Repeat. Then maybe YOU can tell US what you find about the change of tone. That would be very informative for all of the readers, I am sure.

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I've found that using a single edge razor blade works well for top

removal.  As with all sharp tools keep your fingers out of the

way and watch what you are doing.  An artist spatula works

well for the upper block.

Worst case scenario is that you're going to crack the top and

that's just give you something else to learn to do by repairing it.

 Actually the worse case is probably putting a spatula through

the top but with a violin in the white it's not that hard to re

glue it and smooth it out.

Good luck, you'll have fun.

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quote:


Originally posted by:
Johnmasters

gtm,

Since it is hobby project for insight, why not put on the fingerboard first. Then play against another violin before any finish is used. Put on the first coat of Tung, dry, play. Repeat. Then maybe YOU can tell US what you find about the change of tone. That would be very informative for all of the readers, I am sure.

That's a great idea. Now don't laugh... promise. I don't play so there comes a wee bit of a problem. Of course if there are any members who live in the Los Angeles area who are willing to take it out for a spin that would be great.

Nobody has contacted me (snif snif) with an interest in demonstrating / learning how to apply and rub tung oil. If it's a nice day morning or early afternoon I could get 1 or 2 coats on so that would give an opportunity for the before and after recordings For that matter it could also be video recorded and put on the net and charge admission. Not.

Recruit some college students and bribe them with food. The only violin teacher I really know is at Santa Monica College and the music director is an Oberlin Alumni also.

If anyone else has some ideas please toss them out.

Cheers,

gtm

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James Brown's shop is in Claremont, if that is not too far. And there are lots of violinist hanging around that area. Especially during the Michael Darnton workshop there...

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quote:


Originally posted by:
COB3

James Brown's shop is in Claremont, if that is not too far. And there are lots of violinist hanging around that area. Especially during the Michael Darnton workshop there...

Hi Cob3 and all:

It's about 45 miles east of me. There are several colleges with music programs in the area which might explain the crowd. I don't know these people so if someone does and wants to kick it around I'm game.

I was going to order a 1/2 liter from leevalley.com but decided a liter might make more sense for I could decant into smaller containers if people are interested. Also have a veneer saw from them which may prove to be useful in helping to remove the top.

Something that I keep forgetting to mention was using old shampoo bottles with the pop top. Large quantities come in metal cans because it's light sensitive, while for short term storage the plastic bottles with a spout work quite well I discovered what may be a problem. It was stored in a cool dark place maybe for 2-3 months until the next job. On more than one occasion I would find the bottles had their sides partly collapsed. Since it was more than a barrometic pressure drop I'v thinking it's leeching out some of the polymers in the plastic or something is causing an out gassing through the plastic. I never had any problems with the oil even though it was several years old.

I've some wood cigar boxes that I've wanted to oil. They don't represent a lot of work so this will be a good test to check oil quality before putting it on a violin.

Cheers,

gtm

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quote:


Originally posted by:
gtm

Nobody has contacted me (snif snif) with an interest in demonstrating / learning how to apply and rub tung oil. If it's a nice day morning or early afternoon I could get 1 or 2 coats on so that would give an opportunity for the before and after recordings For that matter it could also be video recorded and put on the net and charge admission. Not.

If Mcarufe is right about the film being thin, perhaps it is rubbed on with a rag, thin films throughly dried. One could do this with warm varnish too.

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Ive given this a bit more thought and now wondering if I should consider making a sound post and stringing it to get a sound sample before any work is done. Granted there will be a bunch of variables introduced in thinning and re-gluing the top, fitting a new sound post and stringing again for a new sound sample before oiling.

Any gut feelings it this is necessary or will the thinning make such a significant difference that the results would be meaningless?

.................

All the coats after the first and 2nd are quite thin. In an earlier post I had suggested 20-40 drops per sq ft for each additional coat. My postal scale only weighs in grams, not sure if that will be able to identify if there is any weight loss when rubbing and then drying. There will be some loss when sanding the first coat and maybe the 2nd, after that it's just adding coats. I don't know if it was the supplier's site that suggested 3 coats but I found 7 gave the results I wanted in my boat.

I'm going to do some testing on scrap, then cut a thin section and put under my microscope to see what the actual penetration level is. I was not planning on using any sealer which may actually penetrate deeper than the oil. I'm still questioning which will have a harder surface and which will be more elastic and perhaps deaden the sound when in fact a harder more brittle surface will provide better sound.

Cheers,

gtm.

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Hi gtm;

Are you talking planning or you are actually performing these operations?

My gut feeling sample or varnish (different thickness of coating etc) won't make mush of difference in tone.

The easiness of vibration will make greater difference. That is, how solid is your violin. Wood being used, weights density and thickness of each its parts are out weight the varnish..

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I think it's a great idea to set it up beforehand, gtm. If by any chance the violin sounds good as it is, it'll save you the time and hassle, and if it doesn't, it will be a good learning experience.

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quote:


Originally posted by:
gtm

I'm going to do some testing on scrap, then cut a thin section and put under my microscope to see what the actual penetration level is.

gtm.

Assuming that you have a microtome capable of cutting a very thin section without crushing, shredding, or otherwise altering the sample, I personally would find it academically interesting to view such a sample under a microscope. However, does anyone know the correct depth of oil (or any varnish) penetration for optimal sound? There seem to be so many variables - wood quality, amount applied, degree of pressure, speed of application, temperature, humidity, drying time, etc. Can it be said with any certainty how a micrometer or two difference in the finish affects the sound? Very interesting to read all these ideas!

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quote:


Originally posted by:
doctahg

quote:


Originally posted by:
gtm

... cut a thin section and put under my microscope to see what the actual penetration level is.

gtm.

Assuming that you have a microtome capable of cutting a very thin section without crushing, shredding, or otherwise altering the sample, I personally would find it academically interesting to view such a sample under a microscope. However, does anyone know the correct depth of oil (or any varnish) penetration for optimal sound? There seem to be so many variables - wood quality, amount applied, degree of pressure, speed of application, temperature, humidity, drying time, etc. Can it be said with any certainty how a micrometer or two difference in the finish affects the sound? Very interesting to read all these ideas!

Hi doctahg, Mauricio, yuen and all:

Ha,microtome I want one!!!

I was going to slice across the grain with a veneer saw to take a 1/32-1/16 thick sample and look at it edge on. There is no need to see through the sample at some super resolution. My objective(?) is to have a better understanding if it's as good, equal, or better than varnish. Are we dealing with a stressed skin where the finish plays a significant roll in sound production which is desirable. Best analogy I can come up with is say that of a gear and a leaf spring where the substrate makes the difference in their properties. The gear is hardened on the outside and soft inside to absorb the shock. However, the spring is elastic and the bimetalic skin protects the substrate and adds to the function. At some point I will need to examine some of the properties of a trashed violin essentially for penetration and hardness.

I agree there are so many variables, we have some known history with varnish and an unknown with tung oil which has different properties. Do I expect to take a sows ear and convert to a silk purse ... no. Do I expect a difference yes, can I identify that at least it's not harmful to sound production and an alternative finish. How many coats are needed to seal and are eye pleasing without having excess. We have been given examples of satisfactory results but little else.

In email I had suggested to Mauricio using index cards and coating samples with varnish and tung oil. Once dried some observations can be established as to how each sample reacts to vibration, elastic properties, distortion, memory, etc. This may be more valid than using on a violin because of the variables.

If I'm going to do this then will need to know what varnish to buy and a brand of index cards. It would be nice if I could recruit someone to do the varnish to their liking since I claim ignorance.

Cheers,

gtm

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quote:


Originally posted by:
yuen

Hi gtm;

Are you talking planning or you are actually performing these operations?

My gut feeling sample or varnish (different thickness of coating etc) won't make mush of difference in tone.

The easiness of vibration will make greater difference. That is, how solid is your violin. Wood being used, weights density and thickness of each its parts are out weight the varnish..

Sorry yuen hadn't answered your questions.

Thanks for reminding me I really need a check list for I want to weight before I do any work and then at various stages.

I'm planning to do this when: The violin and the tung oil arrive.

The violin should arrive Monday from Colorado. The seller says the wood is from "his" 50 year old trees but doesn't say if aged. The fingerboard is not glued to facilitate top removal for thinning which he recommends and is sending diagrams for areas to be thinned. Since this will be a new process I have no idea how long it will take... 1 day, a week? I will have to make a thickness dial indicator for that aspect.

The tung oil should be in the early part of the week so I can proceed with test samples to verify it's what I want to use. If all goes as planned and I can get 2+ coats dried in a day and should have some initial results within a day or so including microscope examination.

In the long range I agree it probably won't affect the tone, it's the loudness which may be affected. If it's hard but not brittle as varnish then it may be canceling out/suppressing some sympathetic overtones or harmonics.

I will be at the mercy of someone to play, for that to happen a sound post needs to be made and set. For this reason I am inclined to not attempt a recording before removing and thinning for another would have to be made again.

Cheers,

gtm

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quote:


Originally posted by:
yuen

Hi gtm.

Good for you and we will be delighted to hear your successful result. (armchair quarterback, I am)

Hi yuen and all:

Hahaha, you didn't think you were going to get off that easy??

To ground or not to ground that is the question? I see a lot of beautiful modern violins with the body left with natural finish but the neck, peg box and scroll have some color added. What to do?

..........

Violin arrived today with only the blocks glued so the fun begins.

Cheers,

gtm

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Here are a few of violin and first coat of tung oil on cigar box. Was late night and no power sanding. Daylight will expose to sun and hopefully have more coats and high speed orbital sander. I'm interested to see how it will fill in what appears to be fairly porous wood and how many coats it will take.

http://home-and-garden.webshot...album/562839445EXdweX

Cheers,

gtm

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