So Stradivari used shellac!

[Favinger]

Just read in Smithsonian Institution "Research Reports #107 winter 2002" that on the Axelrod inlaid violin "the dark substance is shellac" The work was done by Melvin Wachowiak under a project run by Gary Sturm to analyze Stradivari's instruments. Does anyone know anything about this project? Are any papers published of the results? I keep hearing about this project but can't get any answers as to what is being done or has been done. According to the article CT scans have been done; are they available to researchers? I remember learning shellac was not available in the 17th and 18th century but that a lac derived pigment was; any comment?

[William Johnston]

I don't know the name of the book but there is some book written in German, so I can't read it, but it has photos of a lot of old violins by famous builders. Some of the photos are taken in ultraviolet light so you can see the colors that the varnish glows in UV light. An interesing thing about shellac is that it glows bright opaque orange under UV light but none of the Strads or other Cremonese violins that I took the time to look up glowed this orange color. I don't know anything about these recent tests though.

[Michael Darnton]

ehhhhhhhh..... I'd sure want to see the original article. I always take this "scientific" stuff with a grain of salt, and have learned to run the other way when someone mentions "science" and violins in the same sentence (the use of quotes around "science" is *completely* intentional!) The problem is contamination from subsequent retouching and polishing, and the abilities of the person doing the research to recognize that--I'm not particularly confident in that ability. Or do they mean lac color, which is a possibility, since the color pre-dated the use of the resin as a varnish material?

[This message has been edited by Michael Darnton (edited 03-13-2002).]

[Favinger]

I am of course very dubious. As a scientist, I am embarrassed as to how bad most science is that is published about violin. I would think the Smithsonian Center for Material research would get it right. They have an excellent reputation, then so does NASA and they gave us the pitiful "life on Mars meteorite"fiasco. The black substance is the fill on the inlay that I assumed was india ink and resin. The analysis was done with infrared light but no more info. I don't know if they

looked for a "glow" or not. Any florescence would be further into the infrared so it would not be visable. I am assuming they used an infrared spectophotometer and fingerprinted the spectrum against known resins and lac forms.

I just did a search and found it online at www.si.edu/researchreports look for #107 page 2 and 6. Don't expect to learn much tho an interesting article and fun read.

Have any real experts (i.e. people who really know Strads and have worked with many) been asked to contribute to the research? Everything I read about this project is in a general infomation form with no details to make meaning of the data.

[This message has been edited by Favinger (edited 03-13-2002).]

[Richard4u]

I use shellac and I think it's wonderful.  My guess is that violin makers used what they had available, including the same things furniture makers used back then.  This would explain why sometimes a violin did have a ground coat while other times, the maker didn't apply a ground coat.  I would assume this is because sometimes there was a shortage of supplies so they just moved forward because after all, they had to eat.  They couldn't just stop making instruments because some ingredients were hard to find.

[MikeC]

wow a 20 year old thread    well they must have had access to shellac after all where do think the lac dye came from and most of them have been french polished and that's mostly shellac but we now know the varnish itself is an oil / conifer resin varnish.  

I wonder if lac dye may have been used a coloring agent in the varnish.   Would that have been detectable in more recent analysis? 

[franscoz]

1 hour ago, MikeC said:

wow a 20 year old thread    well they must have had access to shellac after all where do think the lac dye came from and most of them have been french polished and that's mostly shellac but we now know the varnish itself is an oil / conifer resin varnish.  

I wonder if lac dye may have been used a coloring agent in the varnish.   Would that have been detectable in more recent analysis? 

1 hour ago, MikeC said:

wow un thread di 20 anni    beh, devono aver avuto accesso alla gommalacca, dopotutto da dove pensi provenga il colorante lac e la maggior parte di loro è stata lucidata alla francese e questo è principalmente gommalacca, ma ora sappiamo che la vernice stessa è una vernice a base di olio / resina di conifere .  

Mi chiedo se il colorante lac possa essere stato usato come colorante nella vernice. Sarebbe stato rilevabile in un'analisi più recente? 

It's late but no too late, I did this picture with wood lights, the results Is that. 

[franscoz]

25 minutes ago, franscoz said:

It's late but no too late, I did this picture with wood lights, the results Is that. 

The fluorescent spot Is shellac, evidently the varnish whether with oil or alcohol, respods different.

[MikeC]

1 hour ago, franscoz said:

It's late but no too late, I did this picture with wood lights, the results Is that. 

What are we looking at in this picture.  What violin is that and what finish is on it?    I see you responded in Italian.  I am trying to learn to read Italian thanks!  

[Bill Yacey]

I remember reading someplace that the black filler on the decorated violins was mastic. It could have been Heron Allen, but I'm not sure. It could well have been just a wild guess, rather than any sort of conclusion from careful analysis.

[Davide Sora]

4 hours ago, Bill Yacey said:

I remember reading someplace that the black filler on the decorated violins was mastic. It could have been Heron Allen, but I'm not sure. It could well have been just a wild guess, rather than any sort of conclusion from careful analysis.

The word mastic is often used as a synonym for putty, not necessarily to indicate the use of Mastic resin. It is much more likely that protein glue was used for the black filler, as recent analyzes have shown:

malagodi_et_al_Stradivari_APYA.pdf

[Bill Yacey]

Thanks for the clarification Davide!

[David Burgess]

Stradivari using shellac? Why not? By Stradivari's time, trade with the orient was common. With the Americas too.