Violin Forum/Message Board

[actonern]

I'm interested in why so many overpolished (shellac or similar) golden period oil varnished instruments don't have the same varnish film breakdown as would be the case if the maker had put a lean oil varnish on top of a fat layer.

Is the shellac not an extreme version of "lean" or is there something about the material or perhaps the trivial thickness of it that allows these overcoated instruments to remain bowling ball smooth?

Best regards,

E

[Michael Darnton]

Shellac is leathery, not brittle.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[actonern]

Hmmm... in flake form its brittle... if melted in alcohol and then allowed to reharden from alcohol evaporation it resumes it's flake and brittle state.

And yet, on large panels of french polished furniture, it does not craze and break down with humidity cycles/expansion contraction.

A remarkable material.

[Canuck]

My favorite violin had been refinished before I bought it. It is, after all, 84 years old, and likely needed it. I don't know what was used on it, but it flakes of very easily, even with a finger nail. I have to be very careful with it!

[ctviolin]

[Michael Darnton]

In traditional painting literature that's true, but from a functional position, it's more useful, having to cope with all of the modern materials which were not in existence when the term was originated, as well as the fact that violin varnishes are not the same as painting varnishes, it's better to think of it in terms of soft and hard.

For instance, there are makers now who use modern lacquer as a finish, often with extra plasticizers to make it look more like a traditional violin varnish. It's inherently soft, even though it's not a "fat" varnish, and hard spirit retouch varnish used over it will craze. Raw shellac, with wax, however, works quite well over it, if one needs to do a repair on a lacquered violin.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[Lemuel]

[Michael Darnton]

Even processed shellac is unusual stuff in wanting to wear rather than chip, and being durable. It's the opposite of sandarac, which is the ultimate brittle stuff. Don't mistake what shellac flakes are like for how the stuff behaves on wood.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[Lemuel]

[kjb]

here is a source for different shellacs.

http://www.shellac.net/pricelist.html