Sealers and grounds

[stradofear]

I have two experiences with old shellac (around 100 years old) being totally insoluble in alcohol. One was a guitar I repaired, and another the violin I learned French polishing on, not knowing that I could have dipped it in alcohol and still not gotten in trouble.

[DarylG]

I have two experiences with old shellac (around 100 years old) being totally insoluble in alcohol. One was a guitar I repaired, and another the violin I learned French polishing on, not knowing that I could have dipped it in alcohol and still not gotten in trouble.

But how do you know it was shellac?

[kubasa]

Yes, I use egg white (glair) only, not as an ingredient. However, I believe that the tannin changes some of the properties of the egg white.

Oded

I would agree with you on this on Oded. I have experienced the same thing but I don't have the chemistry background to know how or if the tannin is changing the proteins in the albumin. Maybe it is breaking them down somehow? I'm happy with what I use and pleased with how it seems to "tighten" the wood but I've wondered about this same thing.

JR

[joerobson]

However, during those first 100 years the shellac was vulnerable to alcohol and chipping. One of the characteristics that I fine most interesting about the good ground is that it dents and seldom [if ever] chips.

on we go,

Joe

[Darren Molnar]

I thought it was reported the Cremonese ground was affected very little by alcohol. Wouldn't this tend to exclude shellac as a major component of their ground?

The fresh blond shellac flakes I've tried took so long to dissolve in the alcohol, I would almost call them very little affected by alcohol, even when fresh, within reasonable limits.

[fiddlecollector]

I would agree with you on this on Oded. I have experienced the same thing but I don't have the chemistry background to know how or if the tannin is changing the proteins in the albumin. Maybe it is breaking them down somehow? I'm happy with what I use and pleased with how it seems to "tighten" the wood but I've wondered about this same thing.

JR

Tannin will bond with the egg white and likely make the coating more water resistant.

Tannin and protein reactions are very numerous and effect 1000`s of things like the amount of protein we digest when we eat to clarifying wine and removing bitterness etc from it(fining agent)

[rgwebb6]

We seem to be talking about shellac as a good ground that seals the wood very well. My next dumb question is "What is the difference, if any, between a sealing coat and a ground coat?" I always thought one sealed the wood from penetration by the varnish and the ground provided a good smooth base for the varnish and enhanced transparency. Or am I wrong and they are one and the same coat?

[stradofear]

But how do you know it was shellac?

On the guitar, I know because I knew what the company was using that year (but I couldn't tell you much about the guitar now--I've scrubbed that period out of my mind). The violin, I assume, because it acted exactly the same, and had the same look.

[stradofear]

The fresh blond shellac flakes I've tried took so long to dissolve in the alcohol, I would almost call them very little affected by alcohol, even when fresh, within reasonable limits.

When I strip violins of mine that I don't like the varnish on, even when the shellac has only been on a week, it's still so resistant to alcohol that I can strip the varnish and not touch the shellac. That's another reason I'm using shellac. :-)

[stradofear]

However, during those first 100 years the shellac was vulnerable to alcohol and chipping. One of the characteristics that I fine most interesting about the good ground is that it dents and seldom [if ever] chips.

I would really disagree. I have never had trouble with shellac chipping, and I've used it in all sorts of violin situations. In varnish terms, it's more like leather.

If I have trouble with young customers' body chemistry rotting the varnish on my own violins, I will spray shellac over my own soft varnish knowing that it won't crackle, even though what's under is relatively fresh and soft. I've also used it for retouching over the work of certain makers who I know use lacquer with softener in it, because it's the only thing that will move with what's underneath and not peel, chip, crackle, etc. It's very tough, but also quite flexible.

A viola that I varnished entirely with shellac about 10 or 12 years ago gets played a lot and hasn't either chipped or worn. I also have used it on some furniture around my house--my dining room table has had it for 10 years. Lots of dents, not a single chip. Unlike what I normally do with shellac, on the table I oiled the wood first, hoping it would yellow down in time, which it has--if anything, adhesion should be bad, not good. Shellac's great stuff--if I were making furniture, it's all I would use.

[stradofear]

We seem to be talking about shellac as a good ground that seals the wood very well. My next dumb question is "What is the difference, if any, between a sealing coat and a ground coat?" I always thought one sealed the wood from penetration by the varnish and the ground provided a good smooth base for the varnish and enhanced transparency. Or am I wrong and they are one and the same coat?

It depends on who you ask, and what they're doing with it. To me, looking at Cremonese varnish the terms are interchangeable.

[CT Dolan]

All I know is, when I look at the violins in the Biddulph book (the del Gesu's) my brain screams "shellac!!" But, when I've had the chance to see really good (old) ground, I can't help but think there's something more to it than shellac alone. The depth and transparency is stunning. Well, I guess I've a lot to learn on this one, so maybe I best shut up.

[Darren Molnar]

When I strip violins of mine that I don't like the varnish on, even when the shellac has only been on a week, it's still so resistant to alcohol that I can strip the varnish and not touch the shellac. That's another reason I'm using shellac. :-)

I've experienced this too, I've used alcohol to strip the oil varnish off a shellac ground and there was still ground left in the wood.

I'm trying a thin coat of oil under shellac this week, to try and get a more wet and lively look to things, a post or two down you mention you've tried it. Did it help liven things up visually or just add a yellow tone to things? My understanding is that this used to be quite a common thing to do with shellac finishes, but it became almost forgotton, or deemed un-needed over time.

[Oded Kishony]

Oil on wood is generally not thought to be good acoustically.

I recall someone telling me about mixing shellac with a drying oil. I can see the possibility if you were to make an emulsion with water, shellac, borax and oil. But I suspec there might be other ways to making the mix without using a base.

Oded

[stradofear]

All I know is, when I look at the violins in the Biddulph book (the del Gesu's) my brain screams "shellac!!" But, when I've had the chance to see really good (old) ground, I can't help but think there's something more to it than shellac alone. The depth and transparency is stunning. Well, I guess I've a lot to learn on this one, so maybe I best shut up.

That's funny. My original inspiration for shellac came at that exhibition. I had been thinking about it, because I already liked the stuff, and was standing next to one of the violins that didn't have much varnish, but a lot of ground, when someone I might call an "old codger" came up, and to no one in particular said something like "Sure looks like orange shellac to me!" I thought about it for a while, and realized he was right, it sure did, so I came home and started working it into my grounds. It's hard for people to swallow because it's such a plebeian material, and doesn't have any exotic associations. All it has is a centuries-long history on fine wood products. . .

Darren, I can't say that the optical effect of the oil on my table is desirable. One of the reasons I gave up on linseed oil was because it looks nice after 50 years or so, but the optical effect is not the "right" one. In side-by-side comparisons with shellac, I still prefer shellac.

[Darren Molnar]

Oil on wood is generally not thought to be good acoustically.

Oded

Hi Oded, I've heard also. But, I wonder if those who say it have tried it, or are just passing info along the line. I'm feeling brave this year and I want to try it myself a few times to get a real world sense one way or the other.

[stradofear]

Oil on wood is generally not thought to be good acoustically.

As with a lot of things, it depends on how you do it. If you dip your violin in a 55 gallon vat of it, and let it soak in for a while, as the Germans seem to have at one time and some 40s-50s American makers did, like Earl Sangster (with oil stalagmites and stalactites inside as the result), the acoustic effects aren't that great. If you mix a couple of drops in an ounce of turpentine and put two coats of that on your violin a week or two apart, giving each full time to dry completely, it seals very nicely, and looks just like oil does, without any negative tonal effect, in my experience.

[Darren Molnar]

Thanks Michael.

[Don Noon]

Hi Oded, I've heard also. But, I wonder if those who say it have tried it, or are just passing info along the line. I'm feeling brave this year and I want to try it myself a few times to get a real world sense one way or the other.

I only tried it on samples, and the damping increased significantly... so I didn't try it on an instrument. It was thick, though, and certainly the thinner you can get it, the less the effect should be.

[actonern]

Fascinating stuff...

Michael (or anyone) have you ever seen shellac runs inside the tops around the f holes of cremonese instruments?

Even padded applications could catch a rag around the f hole and get some inside?

E

[stradofear]

one thing they don't find in the stradivari varnish is shellac, its good for furniture thats about it zulu out

And it's about the only thing they haven't found. Given the entirely non-credible results "they" have come up with--just about everything except the kitchen sink, it seems--I don't have much confidence in "them". I see this month's Strad mag has another article of revelation that will probably lengthen the list of "Stradivari varnish" materials with another half dozen ingredients--maybe the kitchen sink will be represented, finally. :-)

That would be a good exercise for someone, to just list all the various varnish and ingredients "found" so far on Strads. I wonder if posts here have a size limit.

So, at this point in time, I will just settle for something that works and looks better than anything else I've tried so far. I have not stopped testing things, of course.

[lyndon]

cremonese didn't use shellac or seed lac til about 1780 and it was then considered the death of the classical varnish tonally, theres some evidence they didn't even have alcohol strong enough to dissolve seed lac till after 1700, if you want to ignore the scientific evidence that has been presented on this forum about cremonese varnish and go ahead and use shellac just don't ask me to listen to your violins i hate the hard screechy effect of shellac zulu out

[stradofear]

cremonese didn't use shellac or seed lac til about 1780 and it was then considered the death of the classical varnish tonally, theres some evidence they didn't even have alcohol strong enough to dissolve seed lac till after 1700, if you want to ignore the scientific evidence that has been presented on this forum about cremonese varnish and go ahead and use shellac just don't ask me to listen to your violins i hate the hard screechy effect of shellac zulu out

I have read evidence to the contrary of what you are saying, and there was an article on the subject some years ago in STRAD magazine. According to the article, shellac's history on furniture dates back to the mid-1600s. [edited response, so poor victim poster won't fear me and go dark on us forever because of unfriendly Maestronet people abusing him . . ]

[fiddlecollector]

How do you know the Cremonese didnt use shellac, or didnt use it until 1780?? I believe this discussion is about the ground/sealer coat not the varnish proper.(The varnish proper wouldnt look right if it was lake pigments or other pigments dissolved in shellac so it can be safely assumed to get the optical effects of pigments in the coloured varnish, oil is needed .So i dont think anybodys arguing that the top varnish isnt oil based)

Back to the shellac ,it first observed i believe in around 1580 by English literature,dont know about Italian or other. Distillation apparatus have been around for an awful long time ,probably invented by the Arabs.So the notion of alcohol not being strong enough to dissolve seedlac is totally wrong .

On checking ,alcohol in reasonable concentration was first recorded by distillation in the 9th century.

Further proof of alcohol concentration can be shown by experiments done by Paracelcus .

Stills in Italy were first mentioned in texts from Salerno in the 12th century.It can all be easily found on google or Wikipedia.

Another interesting thing i remember reading is that in tests done in the US (cant remember by who) shellac protected wood from moisture absorption in the wood cells better than lacquer,oil varnish,urethane varnishes,phenolic varnishes,Alkyd varnishes,etc... which i personally found surprising as there is alot of stuff around saying shellac has poor water resistant properties.

[Torbjörn Zethelius]

I have also heard that shellac varnish came very late (around 1700). But I would love to learn more about earlier use of shellac, and if possibly I had it wrong.

Edit: I just read this wikipedia article about shellac.