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Italian Violin Varnish of Aqua Fortis "Nitric Acid"


Nicolaus

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Here in Canada, I bought a jug of nitiric acid from a local lapidary mining supplier without any problem. They didn't even pay any attention to how I was transporting it. Another time I bought a fifty pound sack of ammonium persulfate crystals from another supplier, and they made me hire a specialty hazardous goods courier to deliver it to my place of employment. Then after work, I loaded it into my van and drove home with it.

Oh, yeah, you think that's dangerous, I keep a mixture of pure oxygen gas mixed with pure nitrogen gas, and a little carbon dioxide gas in my living room. ALL the TIME. It's starting to affect my memory, though, after all these years.

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A friend of mine (pre terrorism clampdowns etc etc etc) needed some anhyrdous hydrazine to make a reaction intermediate: no one would touch the carriage with a barge pole so he drove a couple of hundred miles to a source, put it in the boot of his car and drove back.

Most 'chemical' substances that we enounter can be handled safely with a certain knowledge.

For myself, I'm expecting to have a bad guy reaction to the latest wood that I'm working (cedar wood-not wanting this to result in this thread going skew-wiff).

Oh, by the way, is it ok to have a fear of HF?

R

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Oh, yeah, you think that's dangerous, I keep a mixture of pure oxygen gas mixed with pure nitrogen gas, and a little carbon dioxide gas in my living room. ALL the TIME. It's starting to affect my memory, though, after all these years.

to say nothing of what will happen when all those photons come through your windows and are trapped by the CO2 molecules. Man, you're as good as roasted, well done................

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Here in Canada, I bought a jug of nitiric acid from a local lapidary mining supplier without any problem. They didn't even pay any attention to how I was transporting it. Another time I bought a fifty pound sack of ammonium persulfate crystals from another supplier, and they made me hire a specialty hazardous goods courier to deliver it to my place of employment. Then after work, I loaded it into my van and drove home with it.

Are you trying to tell us that your avatar is an accurate representation? :)

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I'm all for making fun of the ludicrous levels of health and safety these days BUT concentrated nitric acid can be very dangerous if handled in ways that might not seem obvious.

No one should ever go out and get some of this stuff and start experimenting with it without first getting an education in how it behaves and can go wrong.

For instance when diluting concentrated acids with water, the acid must always be added to the water and never-vis versa or a boiling/ spitting or explosive reaction can result.

I'm not sure that having copious water or even mild alkali handy would neutralise conc. nitric fast enough to prevent severe burns in an accident.

Concentrated nitric is volatile and fumes with a visible corrosive vapour...which tends to hovver in the area of use if re staining peg shanks etc... I've no idea how fast it neutralises or breaks down in the lung or how much damage it does if inhaled...

This stuff should really be used in a fume cupboard with proper protective precautions. Anyone who takes less precaution than this is taking a risk and anyone who handles this stuff without goggles' gloves, a risk assessment, plan B and a washing and neutralising strategy is an idiot.

The conc nitric I have is in a container made of some kind of high strength plastic. In the old days it used to come in a brown glass bottle!

My use over the years for conc. nitric is restaining boxwod peg shanks. After a lot of experience I recently developed a simple two step proceedure to get the exact effect I wanted without needing to worry too much re health and safety.

1/ Put on full goggles and thick PVC mittens, have neutralising and washing facilities ready, inspect your nitric acid bottle to ensure it is in a safe condition and is in a safe secure and check the lid is tightly screwed on.

2/ Remove goglesand mits, Order Mountain Mahogany pegs.

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I'm all for making fun of the ludicrous levels of health and safety these days BUT concentrated nitric acid can be very dangerous if handled in ways that might not seem obvious.

No one should ever go out and get some of this stuff and start experimenting with it without first getting an education in how it behaves and can go wrong.

For instance when diluting concentrated acids with water, the acid must always be added to the water and never-vis versa or a boiling/ spitting or explosive reaction can result.

I'm not sure that having copious water or even mild alkali handy would neutralise conc. nitric fast enough to prevent severe burns in an accident.

Concentrated nitric is volatile and fumes with a visible corrosive vapour...which tends to hovver in the area of use if re staining peg shanks etc... I've no idea how fast it neutralises or breaks down in the lung or how much damage it does if inhaled...

This stuff should really be used in a fume cupboard with proper protective precautions. Anyone who takes less precaution than this is taking a risk and anyone who handles this stuff without goggles' gloves, a risk assessment, plan B and a washing and neutralising strategy is an idiot.

The conc nitric I have is in a container made of some kind of high strength plastic. In the old days it used to come in a brown glass bottle!

My use over the years for conc. nitric is restaining boxwod peg shanks. After a lot of experience I recently developed a simple two step proceedure to get the exact effect I wanted without needing to worry too much re health and safety.

1/ Put on full goggles and thick PVC mittens, have neutralising and washing facilities ready, inspect your nitric acid bottle to ensure it is in a safe condition and is in a safe secure and check the lid is tightly screwed on.

2/ Remove goglesand mits, Order Mountain Mahogany pegs.

And on a serious not regarding ammonia, which I once ordered -- 30% concentration, which is the max. The company called me. And I am glad. I was informed that the stuff could turn your eyeballs to raisins. And I believe it. There is no more concentrated ammonia on my property.

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Do we really have any evidence that the classical Cremonese makers used nitric acid?

I've never messed with the stuff myself. I have seen others use it to great advantage, but I assumed that it was a way of making the wood look better -- older, artifically. In my mind, I have this idea that the old fellows just made violins that looked new, but I really have no documented factual basis for thinking so, and I've seen so few great instruments in person that I don't have that experience to go on, either.

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Most any acid can be dangerous and should be treated with care. But the real issue about nitric acid is how its products can remain active. For instance, the Fry varnish, made with this acid, is known to darken very slowly over the years. I also suspect that acid treated wood may also very slowly darken. Perhaps some people who have several years experience with nitric acid can comment and correct me.

Staying tuned.

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The conc nitric I have is in a container made of some kind of high strength plastic. In the old days it used to come in a brown glass bottle!

I think that might be glass with an external flexible plastic reinforcement in case you break the glass. I'm extremely dubious about using ANY container for nitric acid. I've never seen it in brown bottles. I've never seen any container used except ordinary clear glass, although I suppose brown glass might preserve it a little better.

One problem you might have with that stuff is corrosion of materials it's stored with. The cap should keep a lid on the fumes, but I wouldn't be completely sure. It's probably a moot point anyway, as suppliers are probably required to treat it as a raw material for terrorist weapons.

You're right about the safety rule of adding acid to water to dilute.

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I think that might be glass with an external flexible plastic reinforcement in case you break the glass. I'm extremely dubious about using ANY container for nitric acid. I've never seen it in brown bottles. I've never seen any container used except ordinary clear glass, although I suppose brown glass might preserve it a little better.

One problem you might have with that stuff is corrosion of materials it's stored with. The cap should keep a lid on the fumes, but I wouldn't be completely sure. It's probably a moot point anyway, as suppliers are probably required to treat it as a raw material for terrorist weapons.

You're right about the safety rule of adding acid to water to dilute.

Nitric acid is often supplied in polyethylene bottles,the stuff i have is in one and i feel safer using the plastic bottle than a large brown glass bottle. Ive only ever had a problem storing HCL which was in a glass bottle and the plastic screw top disintegrated. The adding water to acid thing is a general misconception and generally only applies to sulphuric acid (of the common mineral acids),which is exothermic when added to water or more dangerously the other way around. The worst acid ive used ,which i used to use for plutonium ,uranium analysis is hydrofluoric.Absolutely horrible stuff .If you get some on your skin ,there is no pain but you will probably die not long after.

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We use a somewhat dilute nitric acid/methanol mixture for etching steel welding samples-- it comes in a brown glass bottle with a plastic lid. But this is only a 20% solution. Not nearly so dangerous as the concentrated stuff. I still would have preferred plastic, I think.

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Nitric acid is often supplied in polyethylene bottles,the stuff i have is in one and i feel safer using the plastic bottle than a large brown glass bottle. Ive only ever had a problem storing HCL which was in a glass bottle and the plastic screw top disintegrated. The adding water to acid thing is a general misconception and generally only applies to sulphuric acid (of the common mineral acids),which is exothermic when added to water or more dangerously the other way around. The worst acid ive used ,which i used to use for plutonium ,uranium analysis is hydrofluoric.Absolutely horrible stuff .If you get some on your skin ,there is no pain but you will probably die not long after.

NOW you tell me! :) I used that stuff for years for etching glass, with nary a problem. Weak concentration, I suppose, but strong enough to produce a nice etch on glass in a couple of minutes. No warnings on the package, no special precautions other than nitrile gloves. It's funny that the stuff would eat glass, but had no effect on my polyester and wood silk screen equipment, or the urethane plastic squeegees. Got it on my skin more than I would like to admit, but just washed it off. Even ingested some, IIRC. Didn't taste good.

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NOW you tell me! :) I used that stuff for years for etching glass, with nary a problem. Weak concentration, I suppose, but strong enough to produce a nice etch on glass in a couple of minutes. No warnings on the package, no special precautions other than nitrile gloves. It's funny that the stuff would eat glass, but had no effect on my polyester and wood silk screen equipment, or the urethane plastic squeegees. Got it on my skin more than I would like to admit, but just washed it off. Even ingested some, IIRC. Didn't taste good.

The stuff i was using was very concentrated ,glass etching stuff is only about 1-5 % at most. The effects hardly show with weak concentrations but you possibly may have done some bone damage.It replaces calcium in your bones ,making them suseptable to breakage and problems later on .

I think the fatality dosage for splashes for skin absorbtion is around a 4" square area(16sq.inchs) ,for the stuff i was using.

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Heres a British example:

`ACCIDENT DESCRIPTION

A palynological technique used by geologists involves the dissolving of sedimentary rock with mineral acids (hydrochloric and hydrofluoric acid) to liberate acid-insoluble microscopic fossils. The fossils are then examined by microscopy to determine the age of the rock and oil potential.

A 37-year-old male laboratory technician was performing acid digestion of oil well core and ditch samples with 70% w/w concentrated hydrofluoric acid in a fume cupboard. He was believed to be seated when he knocked over a small quantity (100-230 ml) of hydrofluoric acid onto his lap, splashing both thighs. The only personal protective equipment (PPE) worn was two pairs of wrist length rubber gloves and a pair of polyvinyl chloride (PVC) sleeve protectors. As a result of the fact that the technician was working alone, it is unclear whether the spill was from the digestion cup or the 2-l bulk acid container.

The technician sustained burns to 9% of his body surface area, despite washing his legs with water from a makeshift plumbing arrangement that supplied water at 6 l. min -. No calcium gluconate gel was applied to the affected area and contaminated clothing was not removed during the flushing with water. Following flushing, the technician, who appeared to be in severe pain and shock, immersed himself in a chlorinated swimming pool at the rear of the workplace, where he remained for approximately 35-40 min before ambulance help arrived.

The injured man was hypothermic and hypocalacaemic on admission to an intensive care unit at a nearby hospital, and soon became unconscious. His condition continued to deteriorate despite subcutaneous injections of calcium gluconate and administration of intravenous calcium and magnesium. His right leg was amputated 7 days after the incident. He subsequently died from multi-organ failure 15 days after hydrofluoric acid spill. ``

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That's not nitric acid. You probably used hydrofluoric acid, which is definitely nasty stuff.

I thought that would be obvious since Nitric doesn't etch glass, and he was talking about the dangers of hydrofluoric.

That's interesting to know about the effect on bones, and makes sense. Surprising that so much could be absorbed through the skin. That wasn't common knowledge in the 70's and 80's. The preparation I used was definitely HFl, and was also sold to consumers. I wonder if it was buffered in some way.

I've had a few broken bones, but none of them broke easily :)

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Heres a British example:

`ACCIDENT DESCRIPTION

A palynological technique used by geologists involves the dissolving of sedimentary rock with mineral acids (hydrochloric and hydrofluoric acid) ... He subsequently died from multi-organ failure 15 days after hydrofluoric acid spill. ``

Ok, I promise not to use hydrochloric and hydrofluoric acid on my violins. :) But isn't this quite far removed from nitric acid? I'm still reluctant to use even that, but surely the safety concerns are much different.

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The extreme electronegativity of Fluorine, as I understand it, is part of what makes HF so dangerous to organisms.

No, that can't be. Electronegativity is what makes fluorine gas such a powerful oxidizing agent. But the fluoride in hydrofluoric acid has already oxidized something. It's spent, so it's not going to oxidize anything. You can think of it as being a little like wood. Wood is dangerous because it's flammable. But wood ashes are not flammable because they've already burned.

Fluoride is toxic in large doses, I think because it binds calcium. I guess it probably affects the electrolyte balance, and in moderate, chronic doses it can affect bone. Hydrofluoric acid apparently causes unusually bad acid burns.

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In hydrogen fluoride, the fluorine has not oxidized anything-- no oxygen is present. It is an extremely polar molecule, though, which, as I recall, increases its affinity for organic compounds. I remember this from a class nearly 40 years ago, so it is possible my memory is volunteering its collander impression again...

I think we have several chemists aboard the good ship Maestronet. I will wait for one of them to speak.

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In hydrogen fluoride, the fluorine has not oxidized anything-- no oxygen is present. It is an extremely polar molecule, though, which, as I recall, increases its affinity for organic compounds. I remember this from a class nearly 40 years ago, so it is possible my memory is volunteering its collander impression again...

I think we have several chemists aboard the good ship Maestronet. I will wait for one of them to speak.

Oxidation in chemical terms doesnt always involve oxygen. An oxidant is a substance able to remove electrons from the substance its oxidising. Being itself reduced in the process.So chemically the hydrogen has been oxidised by the fluorine.

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