Dark stain

[Mike R]

Cap is of course correct.  Some old time rifles were varnished with a  colored varnish and not pre-stained, apparently.  What I meant was that in many regions in the 18th, 19th and 20th cent, aqua fortis was the main stain, although I have heard that mountain smiths used such things as tobacco!  As for Fiebings--I have used it, and it is true that with linseed oil finish it will fade in the sun. I believe that Fiebings makes both water based and alcohol based dyes, so be selective.

[Mike R]

the upper rifle is one where I used Fiebings dark brown dye.  the lower rifle has some modern aneline dye I think [I didn't make it]

[wwpete52]

The old fashioned way is to use aqua fortis and heat--if you do not neutralize after application, but instead apply artist quality linseed oil [a dab at a time] it will turn a pretty black. The initial darkness is controlled by the amount of heat applied--I used a blow torch and feathered the stock after acid application.

I second the motion about aqua fortis. It's all I ever use now.

[Three Hawks]

When I saw the title  "Dark Stain"  I got a mental re-run of my  insane uncle's father in law when he lost his grip on the hammer of his M94 putting it on safe the only time he ever went hunting with my uncle and me.    Popped a round right between my feet then stood there and wet himself.

We just unloaded our rifles, got back in my uncle's pickup and went home.  Then my uncle and I went back up into the hills and went
hunting.

Have you ever ridden 150 miles in a '49 Chevy pickup with a man who just wet himself?   It's embarassing, not to mention it smells.  We should'a made 'im ride in the box.

Three Hawks

[Captchee]

A question that i have yet to get a strait answer on concerning AQF . Now please understand im not saying it wasn’t used . It appears it was . But my question  is how common was it to be used as we us it on  gun stocks .  where did it come from ? how did  the old smiths get it ?
 While im sure that  it was probably attainable for folks in the larger cities , what did the back woods, small town smith  who made his own barrels , lock parts and such use .
 Was it ordered and kept in large supply ?
 When did this become available , what’s the history behind it .

We know its first recorded use was  in the late 16century .  But its use  was for a completely different  application

Aquafortis
[aque fortis; aqua-fortis; aqua fortis; aqua ffortis; aq: fortis; aq. ffortis]
The Mediaeval Latin term means STRONG WATERS though it was rarely used in the sense. More particularly it was the early scientific, and still the popular, name of the nitric acid of commerce (dilute HNO/3). Although it does not affect GOLD, it is a powerful solvent and very corrosive, reacting with most metals; hence its use in etching. It was included among DYERS GOODS in ACTS 1704/C004, being used by dyers of SCARLET to dissolve the necessary TIN. SILVER (in the form of coins) was dissolved in aquafortis, and the result was used in the preparation of FURs from animal skins and as a primitive hairdye.
OED earliest date of use: 1594
Found described as for dyers use, FOREIGN Found in units of LB, OZ Found among the DRUGS rated by the GALLON, HUNDREDWEIGHT
See also AQUA REGIA, AQUAFORTIS BOTTLE, AQUATINT.
Sources: Acts, Inventories (early), Inventories (mid-period), Newspapers, Rates, Recipes.
Aquafortis bottle
[aqua fortis bottle]
A LARGE - BOTTLE for carrying AQUAFORTIS, probably made of GREEN GLASS and protected by a wickerwork cage stuffed with straw. The corrosive characteristics of this acid make a good tight seal essential. Possibly, as in modern times, some substance like PITCH blend was used over a glass stopper, whereas CORK, for instance, would have been eaten away by the acid. [Acts (1720)] suggests that such bottles normally contained 4 GALLON, which means that the contents would have weighed about 56 LB. The Gloucester Coastal Port Books record large bottles, listing one as containing AQUAFORTIS and others being carried EMPTY. These may also have been Aquafortis bottles.
Not

From: 'Aqua naphae - Aquatint', Dictionary of Traded Goods and Commodities, 1550-1820 (2007). URL: http://www.british-history.ac.uk/report ... mpid=58688  Date accessed: 20 March 2009.

So how about making it ? Could a smith make his own ? Probably he could . But the real questions IMO , would he ? If not then he would have to  obtain it from  a place which used it and kept a ready supply. Most likely silver or gold mines ..
 But if we look at the definition , we see the following
 

Aqua fortis, or "strong water," in alchemy, is a corrosive solution of nitric acid made from saltpeter. It was used in alchemy as a solvent for dissolving silver and most other metals with notable exceptions of gold and platinum that can be dissolved using aqua regia. Aqua fortis was prepared by mixing either sand, alum, or vitriol, or the last two together, with saltpeter, then distilling it by a hot fire. The gas collected from this condenses into aqua fortis.

The discovery of aqua fortis is credited to Jabir ibn Hayyan sometime around 800 AD.

Aqua fortis was useful to refiners for parting or separating silver from gold and copper; to the workers in mosaic for staining and coloring their woods; to other artists for coloring of bone and ivory, which is done by tinging the items with copper or verdigris, then soaking in aqua fortis. Some also turn it into aqua regia, by dissolving in a quarter of its weight of sal ammoniac, and then use this to stain ivory and bone, of a fine purple color. Book binders also put it on leather, making fine marble covers for books. Diamond cutters used it to separate diamonds from metalline powders. It was also used in etching copper or brass plates. It was mixed with oil of vitriol and used to stain canes to appear like a tortoise shell by applying several coats while the cane is over hot coals. The canes were then given a gloss with a little soft wax and a dry cloth.

Aqua fortis is actually a solution of HNO3, nitric acid, in water.

 So then if the gunsmith wasn’t making it  would they not have to  have gotten it from someone doing  work that’s related to the definition ?
 If so   I have to ask  how much of this type of work was being done in or around these smaller towns where  these gunsmiths were located ?

 This has lead me to  suspect that  most likely  that many gunsmiths of the period  may have used it when available . But most likely used something  more easily obtained , produced  or readily  on hand .
  Maybe the use of this  is basically like the belief of linseed oils and lacquers   for a finish .
 We know these were not the only two oils used .
 If we study some into  gun finishes we find that  other  coatings ranging from wax all the way to fish oils , sunflower oils . Even Tar  type oils , “all  with driers having to be added “, . these things were also used and readily available  to the gunsmith . See like linseed , these finishes never completely dry . Thus we get and see the very dark  colors caused by patina.  Which is really nothing more the dirt and other contaminates that over time collect in the un dried oils .

 So again  im not saying it wasn’t used . Because I believe it was . But possibly not as often as we think of today . Im also not suggesting that anyone here is saying it was the only thing used . I don’t think anyone has  or could say that  with any real certainty.
 AQF works and it works well  and thus in today’s day and age  we use it a lot  .
 But in progressing that use , are we not then  slowly losing the understanding and knowledge of all the other applications  that also may have or were used ?
 I think so . It seems to have become the standard  and the very first thing recommended .
So what ends up happening is we lose the  original knowledge . Case in point . Recently I answered a question ?? I think up in the flintlock forum about  how to drill a strait hole without a drill press . Very reasonable question  in my opinion.
 But what it shows is that  folks don’t realize that the drill press has been around a very , Very ,long time  . Now this doesn’t mean that if  a smith didn’t have a press  that they couldn’t drill a strait hole with a simple brace and bit .  You can  but for many folks  we have lost that knowledge e as to how , simply because  that information is no longer being  passed on

 Anyway sorry for being so long in the word here. Im frobably boring you all to death with this  .

 But these are just some things  that run in and out of my head from time to time  and why I get  excited when I run across  stains  and finishing formulas that do not include  AQF

[Mike R]

I get your points captchee, but aqua fortis seems to have been well established as a wood stain well before the 18th cent--and the chemical seems not have have been any harder to obtain in gunmaking centers than any other needed items--or even some components of varnishes, etc that were used.  No doubt many guns were simply varnished with colored varnish and not stained--and other stains/dyes exist for wood.  But many general texts meant for the general public existed in the 18th and early 19th cent that list aqua fortis as a wood stain/dye, seeming to indicate that it was common knowledge.  Most major 18th cent gun making areas were close to the east coast where european trade and larger city chemists existed. As gunmaking moved west, trade moved along with it--I don't think aqua fortis was necessarily hard to get--but I do agree that it was not the only thing used.  It may be that the widespread use of aqua fortis for stocks is relatively late?  But it has been a traditional stain to those who kept the art alive from the late 19th into the 20th cent.  Aqua fortis gives a color than I have never seen achieved with modern dyes, aneline or otherwise...

[Captchee]

well some of that i would agree with . but others i wouldn’t .
 lets take right now for instance .
 Lets take  todays  transportation of goods and services for instance .   its  a million times more effective then  in the 18th century .
 But lets say  you a gun smith  or simply making furniture in warren Idaho .
 Not only are you not going to be able to just go out and buy a modern stain . But your not going to get AQF unless you order it .
 How about Boise ? Nope  you still have to order it . Granted because its not  greatly used anymore but for a limited few . But the point is still there .
  So if we assume its easier to now get ? How easy would it have been in the 18 or 19 century ? granted  it probaly was more commonaly avalable . but how much greater would that valability have to have been to offset the  ease  of ordering it today ?

  Again I agree that its  now accepted and used by most . But  may this use be really along the same lines as say the belief that  smooth bores and trade guns never had rear sights . That  the TC , CVA , traditions hawkens are  faithful reproductions of real hawkens ?
 People look at these rifles and automatically say hawkens .  To many  the hawken rifle should have been the most  common rifle  during the western fur trade . But  you and I know that  relitivle speaking  they were probably one of the least found rifles of the day .

 How about  an issue  that was common not to long ago , where  our people all look and dress like a 19th century  Ogallala or Miniconjou  warrior . That if we do not have dark skin , we are not American Indian ?
 See what im really getting at is that as long as we  push the popular belief , that belief becomes the accepted  line . Once that line becomes  total in belief  then its very hard to  get people to re evaluate their given knowledge base .

 Take scrapers for instance . I cant tell you how many times  I have to explain about the use of scrapers over sand paper  . Yet  if you ask 90% of the gun smiths today  about finishing , they go into  the different grades of papers . When you ask about scrapers , you get a blank look or a  nope I only use paper .
 Now  im not saying there is anything wrong with that . But what im saying is we have come to the  opinion that  it’s a must use . When in fact its not   and at the time the rifles we make  were made , it didn’t even exist yet .
30 years ago when I started building rifles  Boning or burnishing was the norm. it was a needed step . Yet today .
 Many folks today do not seem to know the difference between an English finish and an American finish
 Another point would be materials .
 Take the recent problem with  the musket that blew up .  As you know , the first thing that people started saying was the steel was to soft ??
 They however forget that  the barrel still today is a lot stronger then that used 200 years ago .  See we forget all that  because we have aloud modern  popular beliefs to  taint our knowledge base . Eventually that causes a loss in  the actual information of the time .
So im thinking here that when we answer a question  like this one eric posted . We owe it to eric and others to step up to the plate and say . I use AQF  and it works well . but  there were also other  things used  historically , like XXXXX or XXYY. So you may find one of those  more suited to what your wanting  , trying to replicate / achieve .
 Maybe in doing so we can start to replace the information that’s been lost  or only found in some obscure book  information or foot note somewhere .
 that’s all im saying .

Again, myself I sometime use AQF . I also use leather  stains  and alcohol stains .
 but I also make my own . Gobblers smooth  rifle  I used  tobacco tar  and beet juice  Conc. .
 The under hammer I just finished for short arm  I used a mix of Ox blood  and tobacco Conc., over  AQF  to give its deep dark  brown red ..

 I think how far our knowledge can go concerning these things is only based on asking the question  and then digging to find out .

[Mike R]

can't argue with any of that...I think what craftsmen use today is partly dependent on who influenced them when learning--I scrape and burnish, for example, and know others who do also, but the typical wood worker likely sands.   On the other hand, a close friend of mine, who started making guns before I did and who has made many many more than me, and who uses alot of old ways, was the one who taught me about Fiebings dyes.  He also showed me that a quick "patina" can be applied to the steel parts using Birchwood Casey brass black.  However, the most recent gun he made, a .45 poor boy deer rifle, he used aqua fortis wood stain and acid browned the metal...he had been using Fiebings and brass black for several years...he is always experimenting with 'new' stuff....but his mind is 'traditional'.

[cb]

Some of my thoughts re: aqua fortis

First off I am not a chemist but I have asked a friend who is to help me with some of this. Any misunderstanding of his explanations are my fault, but I believe I understand this enough to present it here in some what of a coherent fashion. If  any of my chemistry is wrong and any one of you can show me in what way it is wrong please set it straight.

Anyway I have also been pondering the question of the 18th/early 19th Century "aqua fortis".
As an example I present the following two formulae for aqua fortis which are from :  "Shepherds' Compleat Early Nineteenth Century Woodworker"
“Common aquafortis” “Take nitre, and green vitriol, not calcined, each 6 lbs.  green vitriol, calcined 2 lbs.  Distill.”
“Simple aquafortis” “take of green vitriol 2 lbs.  nitre 1 lb.  Distil

One thing that I have been found is that after much research into pre-mid 19th century chemical terms is that "nitre" - one of the two components mentioned in not only the above two recipes but in most others - is most often listed in period resources as being Potassium Nitrate (KNO3) aka saltpeter and not nitric acid (post mid 19th sources do seem to use the term "nitre" for both, but period resources usually refer to nitric acid "spirit of nitre". But to add to the confusion some resources also list nitric acid as being aqua fortis with no additional ingredients.AUUUGH! (one resource for chemical terms that has links to others is: http://web.lemoyne.edu/~giunta/archema.html )

1) With that said let's consider salt peter as the possible "original" nitre as listed in the formulae. It is not only a naturally occurring substance, but is also a by product of animal waste, and more importantly it is a strong oxidizer and is the chief constituent of black powder.

2) The second ingredient mentioned is Green Vitriol - aka ferrous sulfate. What is ferrous sulfate? Ferrous sulfate is a by product of the oxidation of iron pyrite or it can be produced by treating iron with sulphuric acid.
Where does one find iron pyrite -
"Pyrite is a frequent associate of all sorts of metal ores. It is common in coal, and in slates and other metamorphic rocks."
"Although pyrite is common and contains a high percentage of iron, it has never been used as a significant source of iron. Iron oxides such as hematite and magnetite, are the primary iron ores. Pyrite is not as economical as these ores possibly due to their tendency to form larger concentrations of more easily mined material. Pyrite would be a potential source of iron if these ores should become scarce. Pyrite has been mined for its sulfur content though. During WWII, sulfur was in demand as a strategic chemical and North American native sulfur mines were drying up. A sulfide deposit near Ducktown Tenn. was found to be able to mine pyrite and other sulfides such as pyrrhotite and pentlandite and produce the needed sulfur as well as iron and other metals."

First method: Oxidation of pyrite can be a naturally occurring process or a man made process in which water (H2O) leaches through the pyrites and when it does ferrous sulfate and sulphuric acid are produced.
Second Method: where would they get sulphuric acid?
"In the 17th century, the German-Dutch chemist Johann Glauber prepared sulfuric acid by burning sulfur together with saltpeter (potassium nitrate, KNO3), in the presence of steam. As the saltpeter decomposes, it oxidizes the sulfur to SO3, which combines with water to produce sulfuric acid. In 1736, Joshua Ward, a London pharmacist, used this method to begin the first large-scale production of sulfuric acid.
In 1746 in Birmingham, John Roebuck began producing sulfuric acid this way in lead-lined chambers, which were stronger, less expensive, and could be made larger than the glass containers which had been used previously. This lead chamber process allowed the effective industrialization of sulfuric acid production, and with several refinements remained the standard method of production for almost two centuries."

Hmmm once again salt peter rears it's hoary head and along with it comes a second component of black powder - sulphur which is a major constituent of iron pyrite!

So based on the above I submit that salt peter and sulphur - two of the components of black powder - may have been either the direct components or used to produce the components of the "original" aqua fortis reagent as used by the gunsmiths of old. There is after all a certain logic to using the same chemicals that were used to produce the black powder which powered the firearms one was making.

FWIW: Eric Kettenburg, who has probably studied the subject of early gun finishes more in depth that just about anyone has stated that there are plenty of citations for AQF being available even in the back country.

Regarding Capt Chee's earlier post quoting Don Newel''s excellent book:
1) Don Newell's book was first printed in 1949 not earlier. That was during the heyday of post WW2 home gun smithing and much of the information had been passed down but from how far back is often difficult to say.
2) Regarding the three brown stains:
A. The first using logwood is a pretty good possibility for dating back to the 18th century, but without citation is left up in the air.
B. The second not so possible, although potassium permanganate was know in the 18th Century it wasn't widely available until around 1830.
C. Nitric Acid and Iron is aquafortis.

Regarding linseed oil - the modern "boiled" hardware variety is nothing like the real properly boiled heat polymerized linseed oil and will dry completely when properly applied. Secondly up until the mid-1800's, most linseed oil was used in conjunction with various rosins and turpentines along with a lead dryer to produce a varnish and was not applied alone as is often done today in the idea that oil was the major American stock finish pre-1850.

Anyway as always an interesting conversation.....

and FWIW an excellent variation of Aqua Fortis can be made using two widely available period materials - apple cider vinegar and iron filings aka ferric acetate - a staing that was used as far back as Roman time for leather and wood. It's good and works similar to AQF (ferric nitrate), but in my experience vinegar/iron doesn't give quite as deep an opalescence to the wood as does AQF.

[Captchee]

very interesting CB .
 one thing i would point out though is that the mix for AQF has to be distilled . its not the mix itself but the concentrated vapor droplets that make the  end result .
 also boiled linseed also will not dry 100 %  even the old  way doesn’t not dry 100%
 Nor does it  seal 100% . It permeable , meaning it will alow  air and mouisture to  travil through it
by 100%  what im getting at is that its dry to the touch but at a molecular level it never dries  and thus collects contaminates .
  You are right in that today’s linseed , is not the linseed of old . Today’s linseed had driers added to it

 now you bring up a point here  that i have been making  what is potassium permanganate ?
well  if you look for  "Condy's Crystals"  another word for it .more information can be found  

In 1659 a German chemist, J.R. Glauber, fused a mixture of the mineral pyrolusite and potassium carbonate to obtain a material that, when dissolved in water, gave a green solution (sodium manganate) which slowly changed colour to violet (potassium permanganate) and then finally red. This report represents the first description of the production of potassium permanganate.

Just under 200 years later a Londoner named Henry Bollmann Condy trained as a chemist. He had an interest in disinfectants and marketed a number of products including ozonised water. He found that when he fused pyrolusite with NaOH and dissolved the product in water it gave a solution that had good disinfectant properties. He patented this solution, and marketed it as Condy's Fluid. The problem was that the solution, although it was quite effective, it was not very stable. This difficulty was overcome by using KOH rather than NaOH. This gave a more stable material, which had the added advantage of being easily converted to the equally effective potassium permanganate crystals. This crystalline material was known as Condy’s crystals or Condy’s powder. Potassium permanganate was comparatively easy to manufacture so Condy was subsequently forced to spend considerable time in litigation in order to stop competitors from marketing products similar to Condy's Fluid or Condy's Crystals.

 but here is  a kicker for ya  another word for it is permanganate of potash or  simply potash .potassium permanganate is the 7th level of  potash .
EI
 
Potash fertilizer= potassium oxide
Caustic potash or potash lye = potassium hydroxide
Carbonate of potash, salts of tartar, or pearlash  = potassium carbonate
Chlorate of potash = potassium chlorate
Muriate of potash  = potassium chloride  
Nitrate of potash or saltpeter  = potassium nitrate  
Sulfate of potash  =potassium sulfate
Permanganate  of potash = potassium permanganate

 but we can say that  chaptchee , this doesnt mean much and   you would be right  if we didnt  try to understand this alittle deeper .

 what is potassium carbonate ? potash  .
 potassium carbonate  is a main  or primary part in potash . its also know by pearlash or salts of tartar the last to being consentrates or  more pure potash

 
 now what about mineral pyrolusite?
 guess what  

Now   this is alittle off topic but . Consider this .
 If you read the second half of the  quote I posted .  We see a medicinal use as a disinfectant .
WELLLLLLllllllll  guess what  . Ever heard of American Indian medicines?
 What do you get when you mix ash with  mud from  the bank of a pond . Can we say  low doses of  potassium permanganate
 kinda fun ha ?

[cb]

one thing i would point out though is that the mix for AQF has to be distilled . its not the mix itself but the concentrated vapor droplets that make the end result .

Charles not sure what you mean exactly, but if you mean by distilled that it has to be "cooked" and then cooled and dripped like making whiskey than I must respectfully disagree - basic AQF,  chemically known as ferric nitrate, is nothing more than iron mixed with nitric acid (usually in a somewhat diluted form) until the nitric dissolves as much iron as possible - a simple, but dangerous process since the nitric acid reacts with the iron and fumes off as a toxic gas. After all reaction has stopped you let the dross settle and siphon off the liquid or strain it to remove the dross.

FWIW - here's the exact formula that the original owner of Wahkon Bay AQF used (he included hydrochloric in his mix as well):

I am the gentleman from WB, and "molarity" is one principal mode of stoichiometric measure of concentration, or moles/liter. Industry often uses "degrees Baume'". I always bought industrial (tech) grade nitric in 42 degrees-Baume', for about $.30/lb in 165 lb (75 kg) stainless steel kegs; hydrochloric acid was 20 deg-Baume', for about $.25/lb in 50-liter HDPE kegs. In terms of percent concentration, 69% and 17%, respectively. The most highly refined and concentrated nitric is about 71%, and HCl is about 19%. Often hydrochloric acid is called muriatic acid in supply stores. Your highschool "connection" should be able to furnish you with small amount of acid(s) for making sufficient browner or stain for many, many applications. I could still buy reagent grade acids in polystyrene cases, four x 5-pint each, for about $324 + haz-mat + shipping per case, but it would mean the finished products would be priced beyond their real market value, so... over 25 years of making and marketing the products came nostalgically evanesced...

for the HCl, that should state about 37% acid for concentrated version, or specific gravity of 1.19 for most refined, concentrated HCl, which is not needed for your purposes. I always used "tech grade", slightly less concentration and purity, but still fine for mixing the iron and nitric for making the concentrated browner/bluer or [Aquafortis] stain, from which I diluted to specific needs before bottling and shipping. Remember, when mixing nitric and hydrochloric acids, one makes "Aqua regia", a mix that is about as corrosive and dangerous as liquids get, obviously, it dissolves the iron [nails] right before your eyes, so one can never to careful handling such a mix, and one must always take pains to avoid breathing the vapors, both from the acids, but also, even more importantly, the nitrogen dioxide gas copiously liberated during the reaction when the Aqua regia dissolves the iron!

Pure nitric acid will not dissolve the metal (iron), so one must add a source of "excess protons" from somewhere, some use water (but remember to add the acid to the water, not the water to the acid), which works, too, but I used HCl with the HNO3 in a 4 to 5 ratio (4 pts HCl, 5 pts HNO3) to form Aqua regia, which PROMPTLY dissolves the iron with exothermic vengeance, I might add!! However, my motive was to make both browner (or bluer, anything that will rust brown will also as well rust blue) and AQ stain from one matrix, dilution factor determined the destiny of each, simple as that...
No, it does not, just have hand, eye, and torso protection on when you do it, the resultant mixture is more than corrosive!! And, the mixture is done in 5 to 4 ratio, by volume, in favor of the nitric, I always used conc. acids for the mix, industrially designated for nitric at 42-degrees Baume', or about 69% acid, sp. gr. 1.42, for HCl, Baume' 20-degrees, about 35% acid, or sp. gr 1.17. Analytic reagent grade will be a bit stronger and purer, and that is fine, too. Once the iron is dissolved, the resultant matrix is still highly acid, so continue to be careful with it. I dilute the resultant matrix to 12% solution for browner/bluer (one part matrix to seven parts water), for AQ stain, I diluted to 40% solution (two parts matrix to three parts water)

The browning/bluing formula I extracted many years ago from a book written by A.O. Zischang, it is easy to make, given the oxidants, a suitable, heat-tolerant container and open-space or ventilation from which to escape the copious amounts of liberated NO2 gas. I made the stuff in large batches in a large (50 liter) HDPE container, but one can whittle the proportions down to managable size and make enough browner/bluer to last a couple smiths their lifetimes.
So, here we go... 300 ml (10 fl-oz) of conc HNO3 (15-16 Molar), 240 ml (8 fl-oz.) of conc. HCl (10.5-12 Molar), mix the acids, in large, heat-tolerant container, add about 30 grams (~2 oz.) of 4d finish nails, do this outside, depart the immediate premises and allow the iron to dissolve, liberating NO2 gas, very dangerous, so get out of there, and isolate the system from any metal objects you care for!! Let this exothermic, almost volcanic, reaction occur, allow to cool, then with deionized or distilled water, dilute this matrix to one gallon, or about 3784 ml, total solution. Store final product in amber glass or polyethelene container. This will give you enough browner FOREVER. To make the AQ stain, follow same procedure, except after reaction has ceased, dilute to only about one-third, or to about 1200 ml (~40 fl-oz) of total product or solution. Now, if you are only interested in creating a stock reagent, then one can approach it by taking only the conc. nitric acid, diluting about 2 or 3 to one with water, by adding acid to the water, NEVER, the reverse, and adding degreased steel wool to the acid solution until no more appears to react, then use it for final product in that state of dilution. Pure nitric acid will not dissolve the iron, it must have "excess protons" within the system, whether from another acid, like the HCl, we cited, or from the water, which obviously need not be that pure, as we need H+ ions, not water molecules...

To reiterate, straight nitric will not dissolve the iron, one must add "excess protons", which can come from either another acid (I used HCl.), or water (not distilled water). The actual oxidation of the wood fibers is actuated by heat, and the mode and intensity of the heat source will greatly affect the final color on the wood. I always use a heat gun (aka, paint-peeler) as control is most efficiently done thusly. When I would make up AQ, the final products [solution] was really a mix of ferric nitrate, ferric chloride, and left over protons (acid complex).

HCl (Hydrochloric and Muriatic, same compound, 20 deg Baume is about 10.4 molar solution of HCl, or about sp gr of 1.17, plenty strong enough to mix with nitric, 42 deg Baume for making aqua regia, the solvent for the iron. HCl in time corrodes the iron to become iron oxide, but we want immediate dissolution with its attendant heat to make the soluble ferric chloride and ferric nitriate solution we all know and love as barrel browner/bluer and AQ stain. The resultant brownish fumes are nitrogen dioxide, an extremely toxic gas, so stand well clear of the reaction.

Also here's a side by side comparison of some aci/iron stains on maple:

the piece at the top was stained with commecial WB AQF as a control - on the lower piece:
left side is vinegar and iron
center is commercially available ferric nitrate crystals mixed 5 to 1 with water
on the right is AQF made by mixing degreases steel wool with Birchwood Casey's Plum Brown which contains about 10% nitric, sulphuric, and IIRC hyrdochloric
All pieces were heated to 375° F until they blushed. They were then neutralized with washing soda at PH 11.3 which is in between baking soda at 8.3 and lye at 14.0. Neutral is 7 and the acid/iron stains all run approximately 3 so 11.3 + 3 = 14.3 divided by 2 = equals slightly alkaline, but since oil finishes are somewhat acid  you wind up just about perfectly neutral. Afterwards two light coats of linseed oil and rosin based varnish was applied to highlight the color.
Not a perfect example due to the quality of the image, but in general the WB AQF and the vinegar are to the brown side of the spectrum while the other two are slightly redder and all three of the AQF stains have a somewhat more opalescent look to them, but the vineager is still nice and when completely finished and burnished it boils down to personal choice.

Bottom line for me - Like you have used a mulitude of stains over the last 40+ years of working wood - both modern and period, but I have never found one for maple (and even some other woods) that gives me the look that AQF does - also I prefer to use as many period materials and methods as possible when appropriate .........
For others I say too - experiment - IMO there is no single best one stain or finish since the "look" is as subjective as anything else in this life.....ones man's meat is another's poison and all that

buenas noches.........

[Captchee]

yes you are correct however  for one little thing .
modern equivalents/ substitutes
 Originally  Aqua fortis was prepared by mixing either sand, alum, or vitriol, or the last two together, with saltpeter, then distilling it by a hot fire. The gas collected from this condenses into aqua fortis.

today we mix nitric acid to iron oxide “ the steel wool on your mix added with hot water IE heated H2O  and wall la,,,,, Aqua fortis .
speaking of which
steel wool  dissolved by white  vinegar also make a wonderful iron stain  
 bill Brockway once told me that he used lamp black to raise the figure  in maple . then stained over it . i have never tried that but  seeing his work  i can say it does  work well

[Captchee]

Im sorry I forgot to place a reference to the above making of AQF
 It can be found here



Cyclopaedia: or, A Universal Dictionary of Arts and Sciences (folio, 2 vols.) was an encyclopedia published by Ephraim Chambers in London in 1728, and reprinted in numerous editions in the 18th century. The Cyclopaedia was one of the first general encyclopedias to be produced in English. The 1728 subtitle gives a summary of the aims of the author:

Cyclopaedia, or, A universal dictionary of arts and sciences: containing the definitions of the terms, and accounts of the things signify'd thereby, in the several arts, both liberal and mechanical, and the several sciences, human and divine: the figures, kinds, properties, productions, preparations, and uses, of things natural and artificial; the rise, progress, and state of things ecclesiastical, civil, military, and commercial: with the several systems, sects, opinions, &c; among philosophers, divines, mathematicians, physicians, antiquaries, criticks, &c: The whole intended as a course of ancient and modern learning.

[cb]

Howdy Charles - yep that is aqua fortis, but it's a matter of interpretation - the aqua fortis produced by distilling of those products in such a manner is in fact just plain nitric acid, only one component of what we now commonly call AQF, which for us is used only for ferric nitrate - iron dissolved in nitric acid.

Aqua fortis, or "strong water," in alchemy, is a corrosive solution of nitric acid (HNO3) in water. It is made from saltpeter. It was used in alchemy as a solvent for dissolving silver and most other metals with notable exceptions of gold and platinum that can be dissolved using aqua regia. Aqua fortis was prepared by mixing either sand, alum, or vitriol, or the last two together, with saltpeter, then distilling it by a hot fire. The gas collected from this condenses into aqua fortis.

So yes in order to make Nitric Acid aka Aqua Fortis one needs to use distillation (according to E. K. though nitric acid was a common item in the gun making areas of SE Penna), but ferric nitrate also aka Aqua Fortis, which was used for staining the wood does not require further distillation. Dissolving iron in nitric acid isn't a modern method or subsitute it is rather a difference in how the term was used for two different processes with nitric acid being the common denominator.

I know reading the old texts can be confusing  (I've torn more than few hairs out over the years ) because dependent on the era the "meaning" changed - it's one reason I cross reference to that dictionary I linked to above as it in most cases offers info on the changes.
Example: nitre as I noted above is at times used for both salt petre and for nitric acid, even in the same book!
But it sure is interesting and I love to study and discuss this stuff, especially with someone who shares my interest, as you obviously do, and doesn't let ego get in the way............(of course there's those who think we're nutcases! LOL!)

steel wool dissolved by white vinegar also make a wonderful iron stain

yep - ferric acetate - iron dissolved in acetic acid. I prefer apple cider vinegar and as I noted above it's use for staining both wood and leather goes back at least to Roman Times and was the major method for blacking harness and other horse gear up until WW1. The mix is often called vinegaroon by leather crafters/

Bill Brockway once told me that he used lamp black to raise the figure in maple . then stained over it . i have never tried that but seeing his work i can say it does work well

I've seen that and still another way is to make a batch of STRONG black tea and apply just prior to or immediately after applying either AQF or vinegaroon - the addition of the extra tannins really can make a difference in the effect between the hard and soft grain layers like this piece:

[/quote]

[cb]

Another good source for period chemical terms:
The Incompleat Chymist: Being an Essay on the Eighteenth-Century Chemist in His Laboratory, with a Dictionary of Obsolete Chemical Terms of the Period
Jon Eklund
Smithsonian Studies in History and Technology, Number 33
Smithsonian Institute Press
Washington, DC, 1975

http://www.chemteam.info/Chem-History/O ... msTOC.html