Stradivari's Ground

[Johnmasters]

Hi J Masters,

Any emulsion that contains water makes the woodfibres stand up, and the surface of the wood expand. In wood finishing a water/detergent solution is rubbed on, dried and finished with progressively finer abrasive.

The aggregate is there to fill the pores and any scratches or pits.

The instruments in the Ashmolen Museum have no aggregate or any sort of filler on, as the fine scratches and some toolmarks are visible. The ground is probably oil or clear oil varnish. However there is the question of what they used to make the varnish and what they used to prepare the surface befor varnishing?

Cheers Wolfjk

They do, but they stand up very little. Have you actually tried this? Are you forgetting that there is a varnish film there afterward? You can smooth this for wood fibers and still have plenty of varnish in place...

[Johnmasters]

Hi all,

J.Master congr. your varnish is great!

I have been following this thread with interest from the beggining. I'd like to know is your dried ground soluble in some solvent?

Thanks

G.

In the spirit of "We don't know what the Strad Ground is" .......... It looks like a varnish, it is a varnish, and it will be an oil varnish. If it polymerises, it will resist anything other than paint stripper. (Methylene cloride)

In fact, I have stripped violins I have previously done. The mineral slows down the action of the stripper. I get them stripped, but it takes some extra time.

[Johnmasters]

Johnmaster,

regarding your surfacant could be ox bile?

So aqueas Phase: water, colloid, particoulate.

Oil phase: oil and ox bile

G.

I actually looked up ox bile when I wanted to change surfactants to try to "legitimize" the stuff back to something that would be available to the ancients. I forget why I rejected it. I decided on lecithin. Others have guessed this too. Actually, lecithin would be in the flax seed itself. I don't know, but I suspect that the "break" in fresh-squeezed oils has lecithin and a few semi-water soluable things like this. One washes out the break with water. If an oil varnish were cooked without doing this, perhaps it would be self-emulsifying in casein-ammonia-water. I don't have flax seed, so I cannot try it.

But if you really want to go historical, this is something to think about. Later varnish makers may have washed out the break. This was an improvement for them, but maybe not so good for violin varnish. I know that Darnton uses fresh-squeezed oil.

Michael, write me an email (JMLUTHIER@sbcglobal.net) and say if it is break-free oil.. I promise I will not tell them that you may be lurking..........

[Johnmasters]

I like that orange yellow colour. Nice work!

Thanks.. if you mean the lower picture with the pair, I don't like it. I prefer the upper picture. It is easy to get reddish brown glazes and I tend to use them. Contrast is the name of the game. I like to reveal a certain amount of wood that is mostly just a tawny color.

But any colors can be done... I think the lower ones were photographed after final spirit coat and before rubbing out. Why has nobody gotten worried about my lean-over-fat? Perhaps you have figured it out already.

[GlennYorkPA]

Short note about my perspective - when I was younger I spent 10 years doing graphic arts, retouching, color proofs exct for photography and other graphic arts. So I might see things differently than others. Shades, hues, layers, reflectivity...fine details stick out to me because I used to make sure that things were reproduced properly.

Diffused natural light shows many things that are rather hidden when in direct sunlight or an incandecent light. If you think about it, incandecent is more yellow, natural light more blue - diffused light has many rays bouncing around and that bounces differently in reflections on the varnish - direct sunlight can often illuminate layers better when you can't see them in diffused.

So to answer your question yeah good lighting makes a big difference. I prefer natural light. Especially when I'm varnishing.

As far as appreciating the ground layer, full varnish or not if you look closely you can see the layers and the differences of refraction between the two. Variations of chatoyancy (cats eye effect). When I see a cremonese instrument I can tell the ground lightly bends the light... in a unique way. I think that is just because over time being around those instruments you get a feel for what the cremonese guys were doing with their wood and varnish.

If you are referring to the authenticity of the Messiah brought up by stewart pollens - i'm not sure that they discussed varnish as much as construction of the instrument itself -( treble f-hole being off- different knife marks inside the instrument in unusual places exct...)

I'm not sure if one could authenticate a cremonese instrument just by diagnosing the ground effects or measuring with some sort of optical device - thicknesses vary - french polishes invade varnish - exct.... but there is a "look" that the cremonese instruments have just like the venetian makers have a look and the naples makers have their own look as well.

Keep in mind - I honestly think the secret of strad was every point of his craftsmanship was well done and thought out - good wood - good arching, good f-hole design, good thicknesses, good rib structures, good varnish... If you had bad wood and "the cremonese" varnish and slapped it on an instrument - I don't think it would be the magic sauce.

I'm still working on a ton of photos putting them together to show how different resins and minerals react in emulsions - or layers - and how chatoyancy can be souped up with different variations together. I think it would be helpful - as melvin said in another thread seeing is believing... Be patient because i'm pretty swamped at the moment and this is a side research project.

Andrew,

Thanks to this thread, I am learning a new word 'CHATOYANCY'.

Wikipedia defines it as an optical reflectance effect seen in certain gemstones but goes on the say that 'Chatoyancy can also be used to refer to a similar effect in woodworking, where certain finishes will cause the wood grain to achieve a striking three-dimensional appearance'.

http://74.125.47.132/search?q=cache:gqjJ_q...;cd=1&gl=us

This is the first time I have heard that there is a word to describe this effect whereby the flame on violin back is 'holographic' in the bright flames darken and dark ones lighten as the violin is tilted. I assume this is the effect being discussed and I have never seen it on the spruce of violin bellies.

This is an effect that is highly desireable and every violin maker tries to achieve it but most of them do so and without resorting to particulates in the ground.

Glenn

[Johnmasters]

Andrew,

Thanks to this thread, I am learning a new word 'CHATOYANCY'.

Wikipedia defines it as an optical reflectance effect seen in certain gemstones but goes on the say that 'Chatoyancy can also be used to refer to a similar effect in woodworking, where certain finishes will cause the wood grain to achieve a striking three-dimensional appearance'.

http://74.125.47.132/search?q=cache:gqjJ_q...;cd=1&gl=us

This is the first time I have heard that there is a word to describe this effect whereby the flame on violin back is 'holographic' in the bright flames darken and dark ones lighten as the violin is tilted. I assume this is the effect being discussed and I have never seen it on the spruce of violin bellies.

This is an effect that is highly desireable and every violin maker tries to achieve it but most of them do so and without resorting to particulates in the ground.

Glenn

Many thanks Glenn. What seems most important is that the light scattering is normal to the orientation of the fiber. The problem becomes much more clear.

[cbouts]

Yes, John actualy nailed the correct term for the optical effect I believe a few months ago. But yes - the three dimensional look. Where flames don't just roll sideways but also up and down. (flames then the medulary rays) And it can be done with particulate matter.

The more I play around with it the more I'm learning that certain layer thicknesses and minerals will either add or subtract from chatoyancy. Some combination of minerals will heighten the effect.

You can actually produce this effect with spruce as well - in the winter grain. But all this is based on the ground.

[Johnmasters]

Yes, John actualy nailed the correct term for the optical effect I believe a few months ago. But yes - the three dimensional look. Where flames don't just roll sideways but also up and down. (flames then the medulary rays) And it can be done with particulate matter.

The more I play around with it the more I'm learning that certain layer thicknesses and minerals will either add or subtract from chatoyancy. Some combination of minerals will heighten the effect.

You can actually produce this effect with spruce as well - in the winter grain. But all this is based on the ground.

Are you gaurding secrets, or do wish to elaborate? I understand the proprietary point. But the community would not have a real emulsion without my postings. There are many tricks, as the entire system is extremely versatile. Don't mention mineral tpes if you don't want to, but how do you see different types adding to the optical effects?

[violins88]

John M,

When you say "break-free oil", do you mean the stuff used in lubricating guns? That is the only thing I could find.

Thanks

[Johnmasters]

John M,

When you say "break-free oil", do you mean the stuff used in lubricating guns? That is the only thing I could find.

Thanks

I suppose so, rubbing oil into the stock. Not cleaning the bore !

http://www.darwinprice.com/Linseedoil.htm

The last two sections mention "mucilage." These are things that will precipitate out on heating, I think. They must be partially water-compatible because water solution alkalies are used to remove them. I expect any lecithin is in here. At any rate, I think they mean that the mucilage is the "break." Break is a term used by varnish makers.

[Wolfjk]

Hi Wolfjk,

If your contention that 'The instruments in the Ashmolean Museum have no aggregate or any sort of filler............' the the entire basis of this thread would be undermined.

I think the contention here is that early Cremonese instruments had, not only a filler, but a relatively thick layer containing particles but that the particles are so fine you cannot see them. They are invisible to the naked eye but impart some interesting optical properties that only a few experts with trained eyes, can appreciate.

(BTW, Have they finished the refurbishing of the Hill collection?).

Glenn

Hi Glenn,

I spent some time looking at the instruments and there are scratches and tool marks that are covered only by varnish. However I could see specks of red pigment in the varnish of the Messie violin.

I also attended the two seminars at Newark given by Dr Barlow. Some instruments had a ground filler others did not.

My interpretations of the minerals found in the varnish is that they came from the way the varnish was made.

Most of the particles could have come from the lye made from wood ash, which was the general cleaning material and detergent.

Dr Kremer of Kremer pigment explained in one of the talks at Dartington how the varnish could have been made. He suggested wood ash made from burning willow.

I think the contention here is that early Cremonese instruments had, not only a filler, but a relatively thick layer containing particles but that the particles are so fine you cannot see them. They are invisible to the naked eye but impart some interesting optical properties that only a few experts with trained eyes, can appreciate.

I am no expert and have not got a trained eye however I think the optical properties come from the clearness of the varnish and the quality of the wood under it.

Cheers Wolfjk

[Wolfjk]

They do, but they stand up very little. Have you actually tried this? Are you forgetting that there is a varnish film there afterward? You can smooth this for wood fibers and still have plenty of varnish in place...

HI J Masters.

I have been experimenting with wood finishing, making varnish and applying it for some time. My experience is that on hardwoods the smother the surface the better the finish. Any fibres sticking up will diminish the transparency.

Would not some of the water content seep into the wood of the instrument and cause crackling of the varnish later?

Sorry I can’t comment on your instrument, I can’t open any pictures for some reason.

Cheers Wolfjk

[Johnmasters]

HI J Masters.

I have been experimenting with wood finishing, making varnish and applying it for some time. My experience is that on hardwoods the smother the surface the better the finish. Any fibres sticking up will diminish the transparency.

I have not seen this. What do you mean by "some time" ? More than 40 years?

Would not some of the water content seep into the wood of the instrument and cause crackling of the varnish later?

No, the loss of the two fluids in parallel is very complicated. All water is gone by the time the varnish dries. It is nearly all gone by the time the solvent leaves and the varnish is still tacky. Also, the capillary action of the wood is not strong enough to pull the water out of the emulsion.

Sorry I can’t comment on your instrument, I can’t open any pictures for some reason.

Cheers Wolfjk

[GlennYorkPA]

HI J Masters.

I have been experimenting with wood finishing, making varnish and applying it for some time. My experience is that on hardwoods the smother the surface the better the finish. Any fibres sticking up will diminish the transparency.

Would not some of the water content seep into the wood of the instrument and cause crackling of the varnish later?

Sorry I can’t comment on your instrument, I can’t open any pictures for some reason.

Cheers Wolfjk

Wolfjk,

You raise a very interesting point about the wood surface. My experience, and that of many master cabinet makers, is that the final results depend on the effort put in to smoothing the wood. So one smooths and scrapes, wets (to raise the grain), dries, then smooths some more until the surface is perfect.

Is the assumption that this particulate ground removes the need to spend so much time smoothing the bare wood?

It's a good question because I have seen some test patches by a violin maker friend who tested his varnishes on rib wood and didn't bother to smooth it at all. Even so, some of his varnish systems were able to produce clear patches where all the detail of the wood could be seen.

Glenn

[Wolfjk]

Wolfjk,

You raise a very interesting point about the wood surface. My experience, and that of many master cabinet makers, is that the final results depend on the effort put in to smoothing the wood. So one smooths and scrapes, wets (to raise the grain), dries, then smooths some more until the surface is perfect.

Is the assumption that this particulate ground removes the need to spend so much time smoothing the bare wood?

It's a good question because I have seen some test patches by a violin maker friend who tested his varnishes on rib wood and didn't bother to smooth it at all. Even so, some of his varnish systems were able to produce clear patches where all the detail of the wood could be seen.

Glenn

Hi Glenn,

My experience, and that of many master cabinet makers, is that the final results depend on the effort put in to smoothing the wood. So one smooths and scrapes, wets (to raise the grain), dries, then smooths some more until the surface is perfect.

That is exactly how French polishers work. In french polishing a ground and grain filler is used after the preparation to give a mirror like surface.

Italin furniture making used varnishing, and the finish was different from that used for French polishing. There are many violin front with corduroy effect.

The maple wood is not ring porous and needs no grain filler, except to cover scratches and pits in the wood. On many instruments some scratches and tool marks are clearly visible under the varnish and there is no sign of any filler.

I have seen John Dilworth demonstrate the ground filling method at a Newark seminar. His way was very similar to the Rubio ground. After the filler he rubbed rosin oil on the instrument that made the white powder transparent. He shown a finished instrument with beautiful transparent reddish brown warmish.

I also listened to Nigel Harris demonstrate and talk about his mathematical arching at Newark but nut sure it was at the same seminar. Perhaps the Rubio, the Dilworth and Harris grounds are similar with a small variation?

My experience is that a clear varnish ground applied before coloured varnish gives a good appearance. I have a gut feeling that any mineral ground dampen resonance.

Cheers Wolwjk

[Johnmasters]

Hi Glenn,

That is exactly how French polishers work. In french polishing a ground and grain filler is used after the preparation to give a mirror like surface.

Italin furniture making used varnishing, and the finish was different from that used for French polishing. There are many violin front with corduroy effect.

The maple wood is not ring porous and needs no grain filler, except to cover scratches and pits in the wood. On many instruments some scratches and tool marks are clearly visible under the varnish and there is no sign of any filler.

I have seen John Dilworth demonstrate the ground filling method at a Newark seminar. His way was very similar to the Rubio ground. After the filler he rubbed rosin oil on the instrument that made the white powder transparent. He shown a finished instrument with beautiful transparent reddish brown warmish.

I also listened to Nigel Harris demonstrate and talk about his mathematical arching at Newark but nut sure it was at the same seminar. Perhaps the Rubio, the Dilworth and Harris grounds are similar with a small variation?

My experience is that a clear varnish ground applied before coloured varnish gives a good appearance. I have a gut feeling that any mineral ground dampen resonance.

Cheers Wolwjk

Damping resonances (plural) may be a good thing. It broadens them. There are plenty of loud violins that don't sound good.

[David Tseng]

Sacconi was supposed to be the expert on Stradvari's work. He claimed to have seen all the Strad in existence and made repair to 350 of them. I wonder why he would come up with such a different varnishing system without a thick particulate ground? I think Sacconi was more concerned about the tone and his "ground" was to harden the wood. In my experience, the particulate ground would reduce the maple flame effect because the particles would scatter light. Ideally the incident light should fall at a certain angle to the maple fibers to get the reflection. My tool handles made of scrap maple have the best chatoyancy simply by rubbing on tung oil and clear varnish. BTW, I don't have bionic eyes, and therefore won't be able to see light bending underneath 40 microns thick of varnish.

[Don Noon]

Damping resonances (plural) may be a good thing. It broadens them. There are plenty of loud violins that don't sound good.

And there are a lot of quiet violins that nobody would want to play. I am of the opinion that damping is to be avoided. Schleske also holds this view. Broadening the tone is accomplished by reducing the peak response more than the off-peak, but ALL of the response is reduced.

Minerals might not increase damping... possibly the opposite. Fused silica has one of the lowest inherent dampings there is. You would undoubtedly lose some of this by grinding it up and binding it back together, but it still might be less damping than the wood.

[David Tseng]

Strad tops are very light (55-60 grams). Heavy particlulate fillers and the gummy emulsion varnishes would kill the high pitch vibrations.

[Don Noon]

Strad tops are very light (55-60 grams). Heavy particlulate fillers and the gummy emulsion varnishes would kill the high pitch vibrations.

I agree with the gummy varnish part. The mineral filler is not as clear (pun appropriate). Rough estimate is that a 30 micron ground could add 2 or 3 grams... significant, but not a huge number. If it increases the stiffness and allows the top to be thinned out by 0.1 mm, there would be net zero weight increase.

[Bassbow40]

Hi all,

I posted in a past thread a few pics of my last varnish (second violin) .

I have formulated my own ground with a lot of mineral in a lemon juice and vinagre solution, and varnish.

What you think about?

http://www.maestronet.com/forum/index.php?...mp;#entry411987

G.

[Johnmasters]

Sacconi was supposed to be the expert on Stradvari's work. He claimed to have seen all the Strad in existence and made repair to 350 of them. I wonder why he would come up with such a different varnishing system without a thick particulate ground? I think Sacconi was more concerned about the tone and his "ground" was to harden the wood. In my experience, the particulate ground would reduce the maple flame effect because the particles would scatter light. Ideally the incident light should fall at a certain angle to the maple fibers to get the reflection. My tool handles made of scrap maple have the best chatoyancy simply by rubbing on tung oil and clear varnish. BTW, I don't have bionic eyes, and therefore won't be able to see light bending underneath 40 microns thick of varnish.

I have found in these varnish experiments that larger wood fibers make for more of this effect. At least that is what I think I see. Some of the maple in these violins show much less attractive illumination. The varnish and grounds are the same. There is a lot of variability. I have yet to decide on a few other experiments.

And there are a lot of quiet violins that nobody would want to play. I am of the opinion that damping is to be avoided. Schleske also holds this view. Broadening the tone is accomplished by reducing the peak response more than the off-peak, but ALL of the response is reduced.

Minerals might not increase damping... possibly the opposite. Fused silica has one of the lowest inherent dampings there is. You would undoubtedly lose some of this by grinding it up and binding it back together, but it still might be less damping than the wood.

When I read the second paragraph, I immediately thought to Google "silica rubber tires" and found this.

http://www.yet2.com/app/insight/techofweek/14640?sid=350

You and Shleske have the same opinion I had until recently. Now I wonder about selective damping of various sorts. I have a partial experiment in the 6 violins I am getting ready to string up. This will be only an introduction to other experiments. Experiments are better than opinions, although questioning opinions may be a good way to define an experiment. Damping is often misunderstood. You are an engineer and know what it is. Others may think that a mute causes damping, which it does not of course.

Strad tops are very light (55-60 grams). Heavy particlulate fillers and the gummy emulsion varnishes would kill the high pitch vibrations.

Would they? How do you know? People used to say that a varnish should be "soft and pliable" and many made soft gooey varnishes. On the other hand, glass has low damping compared even to wood. Emulsion varnishes do not have to be gummy. Maybe you are thinking of "mayonaise." Particulates may be more dense than oleoresinous films, but the quantities are low and the film is very thin. Don points this out.

I agree with the gummy varnish part. The mineral filler is not as clear (pun appropriate). Rough estimate is that a 30 micron ground could add 2 or 3 grams... significant, but not a huge number. If it increases the stiffness and allows the top to be thinned out by 0.1 mm, there would be net zero weight increase.

It is likely to be stiffer, at least in compression. Even if asphalt were cheaper than gravel, don't you think they would still put gravel in bituminous concrete? I mean, even if the surface was not sticky? The silica tires are also claimed to be high-energy-efficient. I expected that before I even googled. I expect that hysteresis in stretching/compressing is likely to be less than in a purely amorophous polymer film.

[MANFIO]

Nice varnish and violin Giovanni! I miei complimenti!!!

[Bassbow40]

Glenn, research ive seen on Venetian paintings from the same era or before says that they often contain uniformly shaped glass particles of very narrow size range.Usually around 3 to 5 microns.There was no explaination how they produced these particles though.

Hi all,

a recent search, by Prof Padeletti from Italian Cnr institute, found nano metallic particulate in 1500 pottery by Mastro Giorgio da Gubbio.

http://scitation.aip.org/vsearch/servlet/V...1&chapter=0

G.

[Bassbow40]

Hi all,

Johnmaster I'm very appreciate your willingness in sharing with as your work and knowledge.

Today I tryed to make two different emulsions with my varnish following your "puzzle post" mixed to

to recipe of Harris, Sheldon and Johnston.

1- I bleded 30 drops of hide glue and 40 drops of some mineral (Calcium Carbonate, kaoline, gipsum, quarz) in water solution to 5 ml of varnish with a few specks of Soy Lechitine .

2- Same blend except the varnish is with out oil Only rosin.

Soon I'll post some pics.

Thanks again

G.