How to finish violin neck?


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I'm willing to bet you can't sell your violins in California without a warning label...

Acute Potential Health Effects: Skin: It causes skin irritation and may cause skin burns. It can be absorbed by the skin and cause systemic effects. Deep ulceration of the skin of the hands, resulting from occupational exposure can penetrate as

far as the bone in severe cases. Eyes: Causes eye irritation and may cause eye burns. It may cause severe damage with possible loss of vision, transient corneal bulging, residual irregular astigmatism, and anesthesia of the area after bulging resolves. Inhalation: Causes respiratory tract irritation. Inhalation of dust or mist can also cause irritation of the nose and

eyes. Symptoms may include sneezing, rhinorrhea, throat erythema, nasal septum lesions, or perforation with with bleeding, disharge, or crusting Ingestion: Harmful if swallowed. When ingested in small amounts, it can cause burns of the esophagus, with possible stricture formation and perforation of the stomach. Symptoms may include adbominal and esophageal pain, nausea, vomiting, hypermotility, diarrhea, gastrointestinal tract irritation and bleeding, respiratory distress, cyanosis, coma, and death. It may also affect the cardiovascular system (cardiovascular shock, peripheral vascular collapse, urinary system (kidney damage - nephritis with glycosuria, acute tubular necrosis, renal failure), liver (elevated liver enzyme levels, hepatits, hepatic failure), behavior/central nervous system/nervous system (somnolence, ataxia, vertigo, muscle cramps). It may also affect the blood and cause anemia, methemglobinemia (characterized by dizziness, drowsiness, headache, shortness of breath, cyanosis with bluish skin, rapid heart...

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I'm willing to bet you can't sell your violins in California without a warning label...

Acute Potential Health Effects: Skin: It causes skin irritation and may cause skin burns. It can be absorbed by the skin and cause systemic effects. Deep ulceration of the skin of the hands, resulting from occupational exposure can penetrate as

far as the bone in severe cases. Eyes: Causes eye irritation and may cause eye burns. It may cause severe damage with possible loss of vision, transient corneal bulging, residual irregular astigmatism, and anesthesia of the area after bulging resolves. Inhalation: Causes respiratory tract irritation. Inhalation of dust or mist can also cause irritation of the nose and

eyes. Symptoms may include sneezing, rhinorrhea, throat erythema, nasal septum lesions, or perforation with with bleeding, disharge, or crusting Ingestion: Harmful if swallowed. When ingested in small amounts, it can cause burns of the esophagus, with possible stricture formation and perforation of the stomach. Symptoms may include adbominal and esophageal pain, nausea, vomiting, hypermotility, diarrhea, gastrointestinal tract irritation and bleeding, respiratory distress, cyanosis, coma, and death. It may also affect the cardiovascular system (cardiovascular shock, peripheral vascular collapse, urinary system (kidney damage - nephritis with glycosuria, acute tubular necrosis, renal failure), liver (elevated liver enzyme levels, hepatits, hepatic failure), behavior/central nervous system/nervous system (somnolence, ataxia, vertigo, muscle cramps). It may also affect the blood and cause anemia, methemglobinemia (characterized by dizziness, drowsiness, headache, shortness of breath, cyanosis with bluish skin, rapid heart...

So bathing in the stuff is discouraged? :D

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 chromate exposure was a 

 

Hi Jim....You don't mention your actual quaification.......from your tone I assume High school?...I was warned off dichromate by a doctor from UCL London

Actually I did, but maybe not clearly.  I have an MS in Biology and I assess risk from contaminate exposure for a living.  If your doctor says not to use the stuff, then I would listen to your doctor. 

 

I am a novice at violin making.  I have a complete system for spirit varnishing that I purchased.  It includes the use of PD.  I cannot use oil varnishes because I am hypersensitive to VOCs which limits my options.  I'm happy to learn alternative ways of finishing.  Do you tan or stain your wood?  How do you finish your necks?

 

Cheers,

Jim

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Nate and/or Jerry, do you do the second french polish charged with talc before or after varnishing the rest of the instrument?

Thanks,

Jim

What Nathan and I described is what we did at Francais where we were working in restoration so the instruments are varnished before any neck treatment. In a neck graft or neck set, the ground color is applied before varnish (obviously) and the neck polish after varnish is complete.

I have not had problems with PD, unless it is responsible for my cranky demeanor or the funny eye tick.

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Let's not be cavalier about Cr6  in potassium dichromate. I'll repeat what was said above by quoting Wikipedia with this:

 

"As with other Cr6 compounds, potassium dichromate is carcinogenic and should be handled with gloves and appropriate health and safety protection. The compound is also corrosive and exposure may produce severe eye damage or blindness. Human exposure further encompasses impaired fertility, heritable genetic damage and harm to unborn children.

 

In 2005–06, potassium dichromate was the 11th-most-prevalent allergen in patch tests (4.8%).

 

Potassium dichromate is one of the most common causes of chromium dermatitis; chromium is highly likely to induce sensitization leading to dermatitis, especially of the hand and fore-arms, which is chronic and difficult to treat. Toxicological studies have further illustrated its highly toxic nature. With rabbits and rodents, concentrations as low as 14 mg/kg have shown a 50% fatality rate amongst test groups. Aquatic organisms are especially vulnerable if exposed, and hence responsible disposal according local environmental regulations is advised."

 

Coincidentally, in this morning's Star Ledger there is a front page article about the high concentration of Cr6 in New Jersey's public water supplies. I wouldn't joke about our pollution because this stuff is probably the cause of many illnesses and deaths.

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Let's not be cavalier about Cr6  in potassium dichromate. I'll repeat what was said above by quoting Wikipedia with this:

 

"As with other Cr6 compounds, potassium dichromate is carcinogenic and should be handled with gloves and appropriate health and safety protection. The compound is also corrosive and exposure may produce severe eye damage or blindness. Human exposure further encompasses impaired fertility, heritable genetic damage and harm to unborn children.

 

In 2005–06, potassium dichromate was the 11th-most-prevalent allergen in patch tests (4.8%).

 

Potassium dichromate is one of the most common causes of chromium dermatitis; chromium is highly likely to induce sensitization leading to dermatitis, especially of the hand and fore-arms, which is chronic and difficult to treat. Toxicological studies have further illustrated its highly toxic nature. With rabbits and rodents, concentrations as low as 14 mg/kg have shown a 50% fatality rate amongst test groups. Aquatic organisms are especially vulnerable if exposed, and hence responsible disposal according local environmental regulations is advised."

 

Coincidentally, in this morning's Star Ledger there is a front page article about the high concentration of Cr6 in New Jersey's public water supplies. I wouldn't joke about our pollution because this stuff is probably the cause of many illnesses and deaths.

Good point Mr. Molnar.

We use toxic chemicals and dangerous tools in our proffesional continuously. They should all be used with appropriate respect.

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A list of "toxic" woods, which includes ebony and boxwood:

 

http://www.finewoodworking.com/1977/12/01/toxic-woods

 

I'll add that many people have extreme reactions to pernambuco.

 

And that a friend of mine was sick for several weeks after sawing out mountain mahogany peg blanks, outside.

 

We also frequently have exposure to maple, without having any idea whether or not it may contain toxic mildewcides, applied to prevent staining before it becomes sufficiently dry.

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Let's not be cavalier about Cr6  in potassium dichromate. I'll repeat what was said above by quoting Wikipedia with this:

 

"As with other Cr6 compounds, potassium dichromate is carcinogenic and should be handled with gloves and appropriate health and safety protection. The compound is also corrosive and exposure may produce severe eye damage or blindness. Human exposure further encompasses impaired fertility, heritable genetic damage and harm to unborn children.

 

In 2005–06, potassium dichromate was the 11th-most-prevalent allergen in patch tests (4.8%).

 

Potassium dichromate is one of the most common causes of chromium dermatitis; chromium is highly likely to induce sensitization leading to dermatitis, especially of the hand and fore-arms, which is chronic and difficult to treat. Toxicological studies have further illustrated its highly toxic nature. With rabbits and rodents, concentrations as low as 14 mg/kg have shown a 50% fatality rate amongst test groups. Aquatic organisms are especially vulnerable if exposed, and hence responsible disposal according local environmental regulations is advised."

 

Coincidentally, in this morning's Star Ledger there is a front page article about the high concentration of Cr6 in New Jersey's public water supplies. I wouldn't joke about our pollution because this stuff is probably the cause of many illnesses and deaths.

Jerry beat me to it so I won't repeat what he said.  For Cr6 the carcinogenic effects are through ingestion and inhalation, not through skin contact. So while gloves are important, an appropriate respirator and out door use (or in a hood) is more important.  When reading LD50 numbers remember to scale the weight.  The traditional weight calculated for humans is 70 kg.  Although that number recently got raised to 80 kg for U.S. populations.  <_<  A more important number would be the NOEL (no observed effect level) or LOEL (Lowest observed effect level) for assessing safety concerns.  It is also important to realize that these numbers are based on risks at the population level not the individual level.  Most people will not think twice about using turpentine or mineral spirits (white spirits).  A brief exposure (5 minutes) to the former will put me on my back for the better part of three days, and the latter will (and has) sent me to the emergency room.  So as they say, your mileage may vary.

 

Cr6 in the water supply occurs in part from bad stewardship of the land but also because sodium dichromate has been, and may still be used in many water treatment plants. Toxicologist are still working out the effects of Cr6.  Current research is indicating a threshold effect where negative effects occur at high dosage with NOEL before that (referring to cancer not dermatitis).  Also on the table is an effort to prove Cr6 is a mutagen in addition to being a toxin, but so far those efforts have not been successful.  I think I'm crossing into TMI here so I'll let it go.

 

Cheers,

Jim

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Let's not be cavalier about Cr6  in potassium dichromate.

WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

 

No joking.  If you sell your PD-treated violins in or to California, they have to have this label, under Proposition 65.  Same, if you use any Cr based pigments.

 

I use diarylide yellow (as Indian Yellow hue), which is very transparent.  Use sparingly: strong tint.

 

Indian-Yellow_X.png

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News stories are often inaccurate. It's their job to be entertaining first, I think. The EPA regulation for drinking water (not enforceable) is 0.1 mg/L for total chromium.  At least they were right about the working group.  If you  want to get into the weeds, here you go.  I'm not referring to you specifically Evan.

 

If the link doesn't work type "Toxicological Profile for Chromium.pdf" into google.  It should come up first.

 

-Jim

 

http://www.atsdr.cdc.gov/toxprofiles/tp7.pdf 

 

If the link doesn't work type "Toxicological Profile for Chromium.pdf" into google.  It should come up first.

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I first got warned off Dichromate by my brother who is a senoir research scientist. It is used as a reducing agent and indicator in his work but they have to be very aware that not only is it toxic but that some workers can become sensitised to it to the extent that a few parts per million will trigger an reaction....From what I can see  would no more coat a neck with this than I would with a lead compound....https://en.wikipedia.org/wiki/Potassium_dichromate......but go on and keep on using it just like Rene Morel if you think you are smart

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I don't think anyone is arguing that it is toxic in the right concentrations. The question is, at the exposure level we use and the way we use it, is it a health risk? I have not found anything supporting the argument that it is.

I wont touch it...if you want to that is your choice.....I have no doubt that you have all the skills required to make a trully great neck without dichromate

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Thank you for that. I am more interested in the bigger issue of toxicity with all the things we use. It would be good to have some very good definitive advice as to the risks we take everyday.

Sounds like someone like Jim Bress is uniquely qualified for this kind of information since it's his day job, but he is also a violin maker so he understands the processes and requirements of that field as well. Thanks Jim for your comments so far. I would love to hear other thoughts you have on specific chemicals we work with.

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Sounds like someone like Jim Bress is uniquely qualified for this kind of information since it's his day job, but he is also a violin maker so he understands the processes and requirements of that field as well. Thanks Jim for your comments so far. I would love to hear other thoughts you have on specific chemicals we work with.

Xylene

Lead solder

Mineral spirits

Ethanol

Potassium permanganate

Denatured alcohol

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Sounds like someone like Jim Bress is uniquely qualified for this kind of information since it's his day job, but he is also a violin maker so he understands the processes and requirements of that field as well. Thanks Jim for your comments so far. I would love to hear other thoughts you have on specific chemicals we work with.

 

 

Xylene

Lead solder

Mineral spirits

Ethanol

Potassium permanganate

Denatured alcohol

Damn it Matt, just when I decided to stop participating in this thread.  :)   I try to stay out of arguments, and this thread hasn't gone there, but I didn't see where else it could go.  Let me think about how to answer this.  It's like me asking you or Jerry "so tell me what you know about violin making".  I will likely have to follow up with questions.  Right now I need to get some sleep before spending the day in another working group meeting.  EPA's not invited to this one.  :)   That's kind of an inside joke.  In my professional world, we sling joke's about the EPA the way you guys do with violist.  All in fun, with me anyway.

 

Cheers,

Jim

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MSDS sheets are a good place to start. But still, you don't know if they are based on old studies, new studies, or what the studies actually focussed on (accidental drenching vs trace amounts in groundwater, for example).

And different people have different tolerances. One whiff of mineral spirits, and I leave the room, but turpentine doesn't bother me.

One thing I'll add to Jerry's list: metallic driers.

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Is there a chance that there can be one procedure for finishing a violin neck?  My way of thinking this morning is that there is the Mittenwald school, Newark, Salt Lake, Cremona and the Chicago school.  Sorry if I missed a school.  Surely the same procedure is taught for neck finishing no matter the school.   Just wondering why there isn't just one answer for necks. 

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