Aqua Fortis

[Zonie]

The comment about the fumes rusting any steel they come in contact with is quite correct.

More importantly, if the fumes are breathed by anything alive, they will attack and dissolve the lung tissue exposed to them.

Fooling with nitric acid can quickly lead to a life of serious breathing problems if it doesn't kill you first.

 

[Crewdawg445]

Indeed, the ferric nitrate solution is certainly going to be the ticket.

I've always used TOW aqua fortis which I'm sure has a differing chemical makeup than true aqua fortis made in a homemade fashion.

 

[Black Hand]

I've always used TOW aqua fortis which I'm sure has a differing chemical makeup than true aqua fortis made in a homemade fashion.

Acid, water and iron - should be the same....

 

[Crewdawg445]

Not entirely sure, figured there would be some restrictions concerning it's makeup for resale to the masses...

You know the gooberment must protect us in purchasing harmful goods now!

 

[Black Hand]

Not really.
Once Aqua fortis reagent is made, the acid is depleted. If one can ship undiluted nitric acid to a non-commercial address, Aqua fortis is nothing by comparison...

 

[Crewdawg445]

Very true.

 

[Billnpatti]

The comment about the fumes rusting any steel they come in contact with is quite correct.

More importantly, if the fumes are breathed by anything alive, they will attack and dissolve the lung tissue exposed to them.

Fooling with nitric acid can quickly lead to a life of serious breathing problems if it doesn't kill you first.

Truer words were never spoken. The brown vapor given off by nitric acid is nitrogen dioxide. The stuff will destroy lung tissue and any other sensitive tissue. Anyone who wants to know more about the health dangers should look up the MSDS for nitrogen dioxide. It is bad stuff. I recommend that anyone who is thinking about using concentrated nitric acid think twice before using it. How valuable are your eyes and lungs? One may think that it may be fun doing it yourself but it is far safer, even though it may cost a bit more, to buy prepared aqua fortis from someone like Laurel Mountain Forge. Or buy some ferric nitrate. Either is a much safer bet.

Just the advice of an old research chemist, take it for what it is worth.

 

[George]

One may think that it may be fun doing it yourself but it is far safer, even though it may cost a bit more, to buy prepared aqua fortis from someone like Laurel Mountain Forge.

i have a question...why is this stuff called aqua fortis? Aqua fortis is the name of nitric acid. When you react iron with aqua fortis you wind up with an aqueous solution of ferric sulfate, and the aqua fortis no longer exiSTS.

[SORRY, MY KEYBOARD HAS JUST GONE PSYCHOTIC. ]

SPENCE

 

[dave_person]

Solution of ferric nitrate not ferric sulfate. Originally, aqua fortis meant nitric acid but it seems that during the 20th century the name got tacked on to nitric acid plus iron. Now it is marketed as such.

dave

 

[Zonie]

Is there no mention of "aqua fortis" being used for stock staining in old, pre-1850 writings?

I've been led to believe there is.

If there isn't, why does everyone seem to think its use was common on pre-1850 guns?

If there are writings which discuss using aqua fortis for stock staining, I suspect the writer was not really aware of what was really being used.

Rather like,

"What's that stuff you used to color the wood?"

"I used this stuff."

"What's it made out of?"

"Aqua Fortis".

"Thanks." and so, the writing begins:

"The stock was stained with aqua fortis and with the application of heat it turned into a beautiful rich brown color."

 

[George]

Solution of ferric nitrate not ferric sulfate. Originally, aqua fortis meant nitric acid but it seems that during the 20th century the name got tacked on to nitric acid plus iron. Now it is marketed as such.

Of course you are right, brain fart.

i have assumed the same, that it is a marketing ploy or that people just don't understand the situation, but that may be a mistake on my part. Zonie asked if aqua fortis/nitric acid, the real stuff, was used for stock staining. That's possible, if we take this item literally:

"THE VIRGINIA GAZETTE
April 13, 1776
STOLEN from the Subscriber, on his March from Augusta to Williamsburg , at New Kent Court-house, on Monday the 9th Instant, a very neat RIFLE GUN, the Stock of Sugar Tree curled, made pretty dark by Aquafortis, a Brass Box and Brass wire, flourished in the Breech, and J. Grattan on the Barrel, below the hind Sight."

I guess it's possible it was actually ferric nitrate, just like today, but was already being called by the wrong name in 1776.

Any builders on the board who use nitric acid straight for staining?

Spence

 

[user 922]

Thanks for the correction! Perhaps the moderator should remove that post -- in case someone fails to read further.

 

[dave_person]

Hi,
In the 13th century manuscript entitled "On Divers Arts" by Theophilus, he describes using aqua fortis (nitric acid) and heat to stain wood a pleasing "yellow brown". I stained quite a few guns using dilute nitric acid with no iron. When heated, depending on the concentration, the acid turned maple pink to orangy. That was the way I used to establish the reddish undertone on maple stocked guns. Then I would apply a brownish stain over it to produce the ultimate reddish brown color I wanted. This used to be my preferred method for maple. Now I don't fiddle around with acid anymore and simply use ferric nitrate. Anyway, nitric acid alone will color and darken wood. If not neutralized, over time it will react with the relative small amount of tannin in maple and turn it almost black. Nitric acid alone will immediately darken wood such as cherry, oak, walnut, or any other species that contains much tannin. In the 1776 note above, the gun may indeed have been darkened by aqua fortis to which the gunsmith added iron. In those days and much earlier (as mentioned at the beginning of this paragraph) acids such as nitric and sulphuric formed the bases of many stains

dave

 

[garra]

Can Aqua Fortis gassing cause surface rusting on metal parts. Reason I ask is that when I pulled a rifle out of my safe that was stained with it , it had surface rust on the metal parts. Other rifles not affected. I have the stuff used to absorbed moisture in there too. I live in a dry climate.

 

[dave_person]

Hi Garra,
Yes. You must neutralize aqua fortis stain with a solution of baking soda and water or wiping the stock with ammonia. The residual acid will rust iron and steel and turn brass greenish with corrosion. Theoretically, if you use ferric nitrate powder and water, neutralizing is not needed but I wipe my stocks with ammonia just in case there is some residual acid.

dave

 

[Zonie]

I agree.

In theory the ferric nitrate should not be a strong acid but if all of the acid was not used up by dissolving the iron, it needs neutralizing.

Even if the ferric nitrate solution doesn't contain any acid, a base like ammonia or even lye on the stock won't cause any rusting or damage to steel or brass parts that are near or in direct contact with it.

 

[Black Hand]

In theory the ferric nitrate should not be a strong acid but if all of the acid was not used up by dissolving the iron, it needs neutralizing.

I have read of the end-user adding additional iron to commercial Aquafortis reagent to ensure the reaction has gone to completion. No additional treatment would then be necessary. Unless one has a pH meter or paper, there is no way for the end-user to verify the pH so a neutralization step is a safe-guard.

 

[George]

Unless one has a pH meter or paper, there is no way for the end-user to verify the pH so a neutralization step is a safe-guard.

Neutralizing done right shouldn't be a problem, but if you want to find out if the pH is lower than neutral, meaning the solution is acidic, you can test it by sprinkling a little baking soda in it. It will fizz if it's still acidic.

Spence

 

[dave_person]

Hi Guys,
Do you understand that neutralizing the acid, regardless of how dilute it is, is such a trivial procedure that not doing it is nuts, stupid, and foolish?

dave

 

[garra]

thanks Dave, I thought I neutralized it. I used the aqua Fortis I bought from TOW. I will give it a wipe down with ammonia just to make sure.