Potassium Nitrite (KNO2)

[Dean_Lapinel]

A top (internationally esteemed) maker uses Potassium Nitrite to brown his violins. Do any of you have any sense of how many makers use this?

[Claire Curtis]

I don't know of any.

I do know a few who use it for aging repair wood. The problem is that potassium nitrate burns the wood, and makes it more brittle; I think most people now hold that it damages the sound. -- if not immediately, then in the long run. (I think it degrades to release nitric acid.)

-Claire

[Dean_Lapinel]

That's what I thought so I was surprised to learn that this elite maker uses the stuff. I'm wondering if it's still used but in a very dilute form.

[MidwesternCheapjack]

I remember that KNO2, formerly called saltpetre, was used to lower the libido of schoolboys. Could it be that makers don't want to squander their 'precious bodily essences' on something less timeless that lutherie?

Dave Gardner (who only used it to make home made rockets in his youth)

[DiemViolins]

Are you talking about Potassium Nitrite or Potassium Nitrate?

A big difference chemically seen!

[longrifles]

Sounds like it's in the class of potassium permanganate and dilute

nitric acid.  It will definitely bring out the

curl and darken the wood and on longrifles that's not a problem.

 On something as thin as a violin back I'm

not sure what it would do to sound, nor how much it would degrade

and break down that thin a wood piece.

Not sure I'd use it on a violin.  Interesting to contemplate

though.  Isn't one of the things about old violins

that the wood has aged (oxidized) for so long that is partly where

the sound comes from?  As well as the

vibrations over the years?  Acid/basic stains will definitely

"age" the wood.  I'd think.  But too much for so thin

a piece?

[fiddlecollector]

I dont think it will do much harm to wood, nitrites are commonly used as a food preservative(namely for cooked meats)It does react with wood and sunlight to produce a sort of toned down version of a nitric acid treatment.

That said my chemistry teacher did her PHD on the cancer causing effects of Nitrites so it makes you wonder what is allowed in food .

[MANFIO]

Hi fiddlecollector! That's why the old saying runs: "It's better not knowing how laws, salsiches and violins are made!!!"

[Lance Bellamy]

I have been doing a little testing with substances used to age wood

prior to varnishing. Below is a photo of  a singe piece of

wood cut into two pieces. One has been treated with 1 Molar

Potassium Nitrite and the other with Imprimatura Dorata primer from

Magister in the following manner.

1. Wood scraped prior to application of primer.

2. Two coats of solution/primer applied with a 15 wait time in

between applications.

3. Placed in front of UV bulb for 8 hours.

4. Two coats of weak tea solution applied with a 15 wait time in

between applications

5. Mixture of Magister Vernice Liquida varnish with 25% pumice

rubbed in and wiped off with paper towel.

6. Placed in front of UV bulb for 8 hours.

7. One coat of magister Vernice Liquida varnish applied - Still wet

in photos

The potassium nitrite had a slightly red tint to it after

application where the Magister Imprimatura Dorata had more of a tan

tint. The colors were very close after the weak tea solution was

applied.

[Dean_Lapinel]

Which did you use? The nitrite or nitrate?

Dean

[Andres Sender]

Would you say the apparent additional depth of the Imprimatura Dorata is a result of the wood or the Imp. D.?

[Lance Bellamy]

I used potassium nitrite - sorry for the typo! As far as the

"additional depth" goes, the piece of wood was sawed in half using

 a band saw. So you are seeing the front side and back side of

the same 3x5" piece cut from a neck block.  One side reflected

light as little better than the other.  So I would say it is

the wood.

[Michael Darnton]

Everything looks good on maple. :-)

......and flat pieces of spruce, too.

[bmccarthy]

I was considering starting a new thread on this subject when I found this one from 2006. Has anyone any experience of either Potassium Nitrate or Nitrite ( not sure which one to use) I've been told by several experienced makers that they use Potassium Nitrate on their instruments so I'm considering experimenting with it. As it's an ingredient in making explosives you need a special license from the police where I live. It's also used in the pork industry for colouring meat....Yuck!! I'm curious to know if anyone has any opinions on using this chemical and has anyone used it successfully.

[Julian Cossmann Cooke]

I was considering starting a new thread on this subject when I found this one from 2006. Has anyone any experience of either Potassium Nitrate or Nitrite ( not sure which one to use) I've been told by several experienced makers that they use Potassium Nitrate on their instruments so I'm considering experimenting with it. As it's an ingredient in making explosives you need a special license from the police where I live. It's also used in the pork industry for colouring meat....Yuck!! I'm curious to know if anyone has any opinions on using this chemical and has anyone used it successfully.

FWIW, bmc, I continue to wonder why we would chemically treat wood without some certain knowledge as to the effects on the structural integrity of the wood. I understand the desire to replicate the effects of nature in a fraction of the time that natural aging takes. Maybe we are willing to exchange short term gains in appearance and/or tonal quality possibly for a drastically reduced lifespan of the instrument. That certainly would support a stream of business over time for us as makers. But there is something about compromising the wood that leaves me ambivalent at best. I have not been immersed in my varnish experiments nearly as long as many here on MN. But what I have done so far has me consistently coming back to focusing on letting sunlight work its will on the instrument in the white or where necessary the light box and using a ground that enhances the effects of oxidation both in terms of appearance and tonal quality. On this latter point, I have been fascinated by the very different effects of some grounds on the appearance of oxidized versus "non-oxidized" spruce -- non-oxidized being in quotes because all wood is oxidized to some extent by the time we begin working on it. In sum, I would rather get to the appearance I want without treating the wood with chemicals (other than what is in the ground) and do my best to get tonal quality through the use of good wood and carving to the characteristics of that wood. If all this sounds sort of naive, it's probably because I come to the Forum to learn. If my comments create opportunities for others more experienced than I to teach, so much the better.

[bmccarthy]

I take it you won't be using potassium nitrate on your next violin so. Thanks for sharing your views though, it's exactly what I was looking for. However, despite what you say,I believe more makers are secretly using this stuff than we are led to believe.

FWIW, bmc, I continue to wonder why we would chemically treat wood without some certain knowledge as to the effects on the structural integrity of the wood. I understand the desire to replicate the effects of nature in a fraction of the time that natural aging takes. Maybe we are willing to exchange short term gains in appearance and/or tonal quality possibly for a drastically reduced lifespan of the instrument. That certainly would support a stream of business over time for us as makers. But there is something about compromising the wood that leaves me ambivalent at best. I have not been immersed in my varnish experiments nearly as long as many here on MN. But what I have done so far has me consistently coming back to focusing on letting sunlight work its will on the instrument in the white or where necessary the light box and using a ground that enhances the effects of oxidation both in terms of appearance and tonal quality. On this latter point, I have been fascinated by the very different effects of some grounds on the appearance of oxidized versus "non-oxidized" spruce -- non-oxidized being in quotes because all wood is oxidized to some extent by the time we begin working on it. In sum, I would rather get to the appearance I want without treating the wood with chemicals (other than what is in the ground) and do my best to get tonal quality through the use of good wood and carving to the characteristics of that wood. If all this sounds sort of naive, it's probably because I come to the Forum to learn. If my comments create opportunities for others more experienced than I to teach, so much the better.

[violins88]

I have not seen any real data/measurements by anyone on the deleterious effect of KN02. Does any one know of any?

The rest is speculation.

[Jose Catoira]

I take it you won't be using potassium nitrate on your next violin so. Thanks for sharing your views though, it's exactly what I was looking for. However, despite what you say,I believe more makers are secretly using this stuff than we are led to believe.

didn't I give you some of the stuff last summer?

By the way, it was not nitrate I was using, it was Nitrite.

I use it in a very non secret way. Make a solution, size the wood and the brush it on.

It works better if you suntan the wood for a few days before slapping it on...

Jose

[violins88]

I was considering starting a new thread on this subject when I found this one from 2006. Has anyone any experience of either Potassium Nitrate or Nitrite ( not sure which one to use) I've been told by several experienced makers that they use Potassium Nitrate on their instruments so I'm considering experimenting with it. As it's an ingredient in making explosives you need a special license from the police where I live. It's also used in the pork industry for colouring meat....Yuck!! I'm curious to know if anyone has any opinions on using this chemical and has anyone used it successfully.

I have used a 4 percent solution. But don't tell anyone.

Regarding the explosives (there, now this thread will be monitored), when I was a kid, I read about gunpowder -- charcoal, sulfur, pot. nitrate. I walked into the drugstore and bought a pound of potassium nitrate. I would not try that today.

[captainhook]

I don't use nitrite or nitrate for tanning, but I'm not sure there is any harm unless overdone. NitrITE can act as either an oxidizer or a reducer, depending on the situation. In food it was generally a reducing agent, but here it would be an oxidizer. NitrATE is only an oxidizer and in a quick test I did some time ago both had the same effect on wood. I was unable to easily find nitrite locally (salad bars no longer use it) so I made a little from the nitrate I had on hand. I haven't tried, but I would expect any nitrate (potassium, sodium or ammonium) to be about equally effective. I may try it and tea on my next fiddle, if I can think of a good reason. Or maybe even if I can't.

Edit: wow, fast posting here. I bought my potassium nitrate in a drug store years ago, too, but I bought 50 pounds of ammonium nitrate last spring for lawn fertilizer.

[bmccarthy]

Hi there Jose. you mentioned it but I didn't manage to scrounge any off you at the time. I got my license so I'll get some and play around with it. . . . .don't tell anyone I'm using it though.

didn't I give you some of the stuff last summer?

By the way, it was not nitrate I was using, it was Nitrite.

I use it in a very non secret way. Make a solution, size the wood and the brush it on.

It works better if you suntan the wood for a few days before slapping it on...

Jose

[Jose Catoira]

Hi there Jose. you mentioned it but I didn't manage to scrounge any off you at the time. I got my license so I'll get some and play around with it. . . . .don't tell anyone I'm using it though.

I thought I had done, Sorry, my bad.

Not that I had a lot of "secrets" to hide...

[Bill Yacey]

I have used a 4 percent solution. But don't tell anyone.

Regarding the explosives (there, now this thread will be monitored), when I was a kid, I read about gunpowder -- charcoal, sulfur, pot. nitrate. I walked into the drugstore and bought a pound of potassium nitrate. I would not try that today.

The whole world is going down the tubes. A kid can't even experiment with home made explosives anymore without everyone getting all excited. It's not like it's nuclear fission material, or anything like that.

When I was a kid my friends and I used to pedal our bike through town on a Saturday morning with shotguns or rifles, heading for the nearby countryside for rabbit or grouse hunting. The local RCMP never even bothered us, as they knew what we were up to. Try that today and see what happens; they'll lock down the city and call in the emergency response and swat teams!

[Don Noon]

The whole world is going down the tubes. A kid can't even experiment with home made explosives anymore without everyone getting all excited.

Oh, sure you can, and you don't even have to leave the house to get a 100-pound bag from eBay. And free shipping!

[joerobson]

I have not seen any real data/measurements by anyone on the deleterious effect of KN02. Does any one know of any?

The rest is speculation.

88,

OK...let's let the speculation rest. Or perhaps discuss it as a separate thread. BUT...it is well established that many makers rely on a variety of "wet chemistry" experiments to "color" the wood prior to ground and varnish. Potassium nitrite, potassium nitrate, sodium nitrite, potassium hydroxide, oxalic acid, ammonia fumes, nitric acid.... The question remains ... Why?

What do you have when you are done? How well do you like the visual effects? ...as compared to what? Have you achieved lasting effects? If so, what?

on we go,

Joe