I am in the process of moving the archives to this board, but here is some info that might help you: It is from Mr. Young of Wahkon Bay Co (2 posts). The second paragraph gives his formula. Hope this helps:
Let me clear up the additive questions here: Pure nitric acid will not dissolve the iron needed for the stain, so one must add some ""excess portons"", either in form of another acid, or just plain water, either distilled water or tap-water, it makes no difference, I always used concentrated (10.5 molar) hydrochloric acid (aka, Muriatic acid), mixed with the concentrated (15.0 molar) HNO3, into which I introduced iron in the form of 4d finish nails. The resultant product, a matrix of very acidic, aqueous ferric nitrate and ferric choride, would be a dark, reddish liquid, which is very strong at this point, too strong for personal safety. (If you add only water for the excess protons, the products will be only the acidic, aqueous ferric nitrate.) I diluted take this liquid to a 40% solution, or 1 1/2 parts water, to one part product. This dilution is not critical, either, as this dilution factor was merely arrived at a compromise between reactivity performance (strength of solution) and shipping/customer safety. I always used a radiant heat source, paint-peeler, or heat-gun, which functions much better than a direct flame heat source, held fairly low (like about 2"") from the wood's surface, but always kept the heat-gun moving, so not to scorch the stock's high areas. The results were always favorable to my eye, but different woods, species of maple, red, sugar, or silver (yuck!), different densities, etc would produce varying results to a degree. I always neutalized with one application of a cotton swab dipped into a solution of sodium bicarbonate (Arm & Hammer), or the stock's tone will deepen (darken) over time. I made and sold untold thousands of bottles of this product over the past 25 years, until supply problems caused me to cease the trade this past year. William Young, Wahkon Bay Co
To respond, shelf-life is not problem, if kept in the amber containers. Best to store in cool, dark place tho, like a basement pantry or cupboard.
LMF, et al. stains, are dyes, and I have some issues with stabiltiy of some dyes, as they fade out from U-V radiation, the typical shoe leather dyes are good examples. On my Whitmore-style silhouette rifle, I ""ebonized"" the stick with Fiebing's black leather dye, which appears to initially stain dark and deep, but must be ""refreshed"" every year or so to keep it from fading, quite a contast on this wood between the upper ramrod and the lower part within the stock!!
Yes, I often add LMF Walnut (not American Walnut) or mix of LMF walnut/cherry over the AQ treatment for added reddish undertones, if desired. Remember, the AQ will continue to react over time with U-V, but rather than fading, it darkens, so it should be ""neutralized"" after application, unless one desires the dark, aged look. With some very hard, straight grain, sugar maple stockwood, I do not neutralize as I desire it to darken as initial response to AQ is not as dramatic as on curly, red maple...
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 dionized 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...
That's the story, not bioengineering or rocket science, but be careful if you undertake this project, as the NO2 is dangerous, noxious, toxic, and some say even carcenogenic... Wear eye protection and rubber gloves when handling any strong oxidants, safety first, stock stain/barrel- browner second!!