All North American wood guitar questions

Construction and repair of Classical Guitar and related instruments
Alan Carruth
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Re: All North American wood guitar questions

Post by Alan Carruth » Tue Mar 20, 2018 4:36 pm

A neighbor went to the store room where she worked some years back for a gallon of blueprinter's ammonia. The door to the room had an automatic closer. The ammonia was in a glass jug, and she dropped and broke it. She just made it out of the room before passing out. She took a few days off...

printer2
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Re: All North American wood guitar questions

Post by printer2 » Wed Mar 21, 2018 12:24 am

I used to work in a brewery and there were areas where we would have a stronger small of ammonia due to leakage. Ammonia can be used for refrigeration. One time we had a serious leak and everybody got the #@%*% out of there. Not a healthy situation.
Fred

Alan Carruth
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Re: All North American wood guitar questions

Post by Alan Carruth » Wed Mar 21, 2018 4:57 pm

The old 'monitor top' household refrigerators used ammonia, and when they leaked it could be deadly. They switched over to Freon as soon as it came along. That, of course, was not without hazards, which didn't show up for along time, but at least there were fewer immediate fatalities.

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RJVB
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Re: All North American wood guitar questions

Post by RJVB » Fri Apr 05, 2019 9:53 am

As to the original topic: here's an (almost) all US-wood guitar, not a CG but if you can build this with those woods a CG (or at least a "cross-over") should be possible too (no?)

Gretsch G9240 "Alligator" wood-body resonator converted to non-metal strings (China, 2018?)
Bolink baroque violin (Hilversum, 1982)
Formerly: Brian Cohen baroque violin (London, 1985), Nadegini modern violin (Paris, 1924)

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Re: All North American wood guitar questions

Post by Frederich » Fri Apr 05, 2019 2:50 pm

If you are patient, you won’t need amonia. UV from day light will bring all those light wood guitars to a glorious amber color in a few years. Think of the old Torres maple guitars, or the many beautiful lutes and theorbos made from maple, yew or sycamore.
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RJVB
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Re: All North American wood guitar questions

Post by RJVB » Fri Apr 05, 2019 6:45 pm

Nothing to do with wood choice and provenance, but is there a reason why plucked instruments don't get a varnish as is used for bowed instruments?
Gretsch G9240 "Alligator" wood-body resonator converted to non-metal strings (China, 2018?)
Bolink baroque violin (Hilversum, 1982)
Formerly: Brian Cohen baroque violin (London, 1985), Nadegini modern violin (Paris, 1924)

Alan Carruth
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Re: All North American wood guitar questions

Post by Alan Carruth » Fri Apr 05, 2019 7:09 pm

Guitars are generally finished using shellac, varnish, lacquer or some other film forming finish. Some makers these days are using 'Tru-Oil' or a similar product, sometimes called a 'wiping varnish'. What guitar makers don't generally use is a colored varnish, which is normal on violins. Varnishes tend to darken with age, some by quite a lot. I believe (without any proof) that violin makers started using dark varnish as a way of 'antiquing' their instruments, since there's a general belief that older fiddles sound better.

Usually, when a guitar maker says they use 'varnish' they're talking about some version of a finish where a drying oil and a resin have been cooked together to form a co-polymer. The resulting tar-like goo is thinned out to spreading consistency and applied, often with a brush. These can range from soft 'spar' type varnishes to harder 'rubbing' varnish, although the latter is more common. 'Spar' or 'long oil' varnishes remain flexible, but can become soft and even sticky in humid weather, and can be hard to polish to a high shine. Books have been written about this stuff, and I won't go much further here.

Violin makers these days sort into two main camps' those who use some sort of oil-resin varnish, and those who use a 'spirit varnish': some sort (or sorts) of resin dissolved in alcohol. They all call what they use 'varnish', although in use spirit varnishes are more like lacquer, as they harden by solvent evaporation rather than a chemical reaction the way oil-resin varnishes do. Violin varnishes tend (tend!) to be softer than most 'rubbing' varnishes: a high polish is not so much valued on violins as it is on guitars.

Again volumes have been written about this. I often think that if you went to a violin maker's meeting and quietly said the word 'varnish' they'd be breaking chairs over each other's heads withing a few minutes. The 'magic' varnish of Stradivari is an ongoing topic for discussion, despite (or perhaps because) it will never be resolved; everybody's opinion is as good and anybody else's.

A friend of mine says that when ever there are a lot of ways to do something, it's a sign either that everything works, or nothing does. In the case of guitar finishes, there is no 'perfect' one. You pick the finish that has the features you want or need, and drawbacks you can live with, and go with it.

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RJVB
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Re: All North American wood guitar questions

Post by RJVB » Fri Apr 05, 2019 7:41 pm

Thanks!
Alan Carruth wrote:
Fri Apr 05, 2019 7:09 pm
Guitars are generally finished using shellac, varnish, lacquer or some other film forming finish. Some makers these days are using 'Tru-Oil' or a similar product, sometimes called a 'wiping varnish'. What guitar makers don't generally use is a colored varnish, which is normal on violins.
So to summarise what I understand is that there may be more variety in the finish of guitars, and no colouring.
Varnishes tend to darken with age, some by quite a lot. I believe (without any proof) that violin makers started using dark varnish as a way of 'antiquing' their instruments, since there's a general belief that older fiddles sound better.
You're probably not wrong; what I recall of iconographic "evidence" is indeed that violins tend to be lighter (though I'd say still darker than lutes, vihuelas and guitars). Still I've seen old "blond" instruments and 19thC instruments that are so dark they almost certainly had a dark to begin with.
a high polish is not so much valued on violins as it is on guitars.
New and newly restored instruments are often quite "high gloss" but they rarely remain that way. Rosin doesn't help, and the body is small enough that you quickly have put your fingers everywhere ;)
The 'magic' varnish of Stradivari is an ongoing topic for discussion, despite (or perhaps because) it will never be resolved; everybody's opinion is as good and anybody else's.
Mostly we don't have any hard evidence that there's anything magic to it that makes it better than the varnish from other famous builders (Amati, Stainer, Guarneri, choices enough). I don't think anyone has sacrificed a Strad to see how it sounds without its varnish ;)

I'm happy enough with the varnish of my violin - soft indeed; I'm pretty certain it has change subtly in the 25y I've owned the instrument.
https://drive.google.com/open?id=0B4xCX ... U5wNTFrcE0
Gretsch G9240 "Alligator" wood-body resonator converted to non-metal strings (China, 2018?)
Bolink baroque violin (Hilversum, 1982)
Formerly: Brian Cohen baroque violin (London, 1985), Nadegini modern violin (Paris, 1924)

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RJVB
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Re: All North American wood guitar questions

Post by RJVB » Sun Apr 07, 2019 11:00 am

Luthier Matti Palonen found a quicker solution, though technically not for a (classical) guitar ;)

https://video-cdg2-1.xx.fbcdn.net/v/t42 ... e=5CAA04E9
Gretsch G9240 "Alligator" wood-body resonator converted to non-metal strings (China, 2018?)
Bolink baroque violin (Hilversum, 1982)
Formerly: Brian Cohen baroque violin (London, 1985), Nadegini modern violin (Paris, 1924)

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Keith
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Re: All North American wood guitar questions

Post by Keith » Sun Apr 07, 2019 1:23 pm

Professor Nagyvary found the magic solution to making great violins--have college students go #1 on spruce soundboards.
be true to the one you love but have many flings with different guitars

guitarras en la espiritu de la:
Marcelo Barbero
Jose Ramirez III

Alan Carruth
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Re: All North American wood guitar questions

Post by Alan Carruth » Sun Apr 07, 2019 8:22 pm

Nagyavari seems to have discovered 'The Secret' of Stradivari about every 10-15 years, but it was always a different 'the secret'. Recent testing by Claudia Fritz et al strongly suggests that there is no 'secret'; that the best modern violin are as good as any that are out there. This is, of course, anathema in much of the violin community where, we note, they make their living selling instrument on commission....

I've been involved in studying instrument acoustics since about 1980. People keep asking about 'the secret', and a huge amount of time and energy has been expended trying to find the answer, to no avail. Eventually you have to start wondering if you're asking the wrong question....

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RJVB
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Re: All North American wood guitar questions

Post by RJVB » Sun Apr 07, 2019 10:07 pm

+++
The only conceivable reason not shrouded in mystery and speculation why older instruments could be better on average is that they've passed an almost Darwinian test of selection of the fittest including, for the older (pre-1850-or-so) ones a rather significant conversion into "modern violins".
Gretsch G9240 "Alligator" wood-body resonator converted to non-metal strings (China, 2018?)
Bolink baroque violin (Hilversum, 1982)
Formerly: Brian Cohen baroque violin (London, 1985), Nadegini modern violin (Paris, 1924)

Alan Carruth
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Re: All North American wood guitar questions

Post by Alan Carruth » Mon Apr 08, 2019 5:00 pm

That's probably part of it. About 2/3 of the violins that Strad made no longer exist, and it's sensible to think that the larger proportion if those 'lost' were the ones that were not as good. OTOH, the French Revolution was pretty indiscriminate in it's destruction, as were the Presbyterians in Scotland and others. The film 'The Red Violin' comes to mind.

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