a few questions about Aquafortis

roseau river rat

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so im reading online about using Aquafortis to stain a maple stock and im getting conflicting information, some people say it needs to be neutralized after its been applied and before applying an oil finish but in reading the literature from track of the wolf on how to apply it there is no mention of using a neutralizing agent so ??
Also is this the best product to use or is there something better ? I plan on staining a period correct Flintlock stock. and where do i get it in Canada ? thanks.
 
The nitric acid in properly prepared aquafortis is spent and no neutralizing should be required. Having said that, I always neutralize with a baking soda and water solution as a precaution and for peace of mind. Aquafortis is generally not used as the final stain today. It is a first step prior to staining. It darkens the wood and increases the contrast in the curl. There are many options for final staining and highliting. You will need to start by deciding if you want to duplicate the look of the stock as it would have looked when first built or 200 odd years later.
 
Not sure where it can be found in Canada. You could make your own If you can find some nitric acid. You would need to do some research to determine the concentration. Aquafortis is nothing more than iron (filings, degreased steel wool, nails ...) dissolved in nitric acid. There are other formulas that also contain hydrocloric (as I recall) acid, but they are generally considered to be inferior.
 
There are two different types of aqua fortis staining. One method is to use a fairly strong solution of nitric acid and I am guessing somewhere in the neighborhood of 30% to 50% solution. I would suspect it might require neutralization. I also think that you have to heat the wood after applying to get the full colour change. The solution that I use is home made and I dilute concentrated nitric (95% I think) to about 30% then dissolve steel wool in it until the acid will not take any more. Extremely important to add acid to water to avoid vapour explosions and also very important to add the steel wool outside your house because the orange vapours are very corrosive. The solution gets very hot and I add some iron then let cool and add some more until the acid is all used up. In use, I wipe the solution onto the sanded wood which gives a washed out coca cola type colour then heat the wood with a hair dryer (or the big element on the stove, if my wife is not home :>) ) until the colour changes and finally a very light sanding with 200 grit sandpaper to remove the fuzz and finally oil finish.
It is my impression that the aqua fortis stains sold by TOW and Dixie and others are more or less the dissolved iron version I described above. I have stained several maple stocks with the stain and have never had any problems with rusting. Final point is that I think you would have to be a company today, to buy concentrated nitric acid, partly because it can be used to make explosives

cheers mooncoon
 
Mooncoon does exactly as I do and, yes, one has to heat the stock after the aquafortis has been applied to get it to blush. When the proper temp is reached, the blushing is rapid and dramatic.

Some of the commercial products are nitric acid and iron and others are nitric and, as I recall, hydrocloric acid and iron. I recommend sticking to the pure nitric acid version. One I like is Dangler's.
 
Hmmm yah not sure I want to mix up my own I would much rather buy it ready made, wonder if Track of the wolf would ship it across the border? Must be available in Canada somewhere?? What about leather dye instead ?
 
Contact Track and ask them. There probably is a source in Canada, if you can find it.

Some people do use leather dye either full strength or thinned as a primary stain, as an over-stain or for shading, but It is not very forgiving and I think it would be a poor substitute - especially if you would be applying it to curly maple. There are other choices such as analine dyes and universal tints mixed with linseed oil or turpentine. Pine tar diluted in turpentine as I recall, which does little in the way of actual staining was apparently applied as a finish in the 18th century. Pine tar is sold today as a treatment for horses hooves. Another home brewed dark finish can be made by dissolving asphalt in turpentine. In all cases, I would want to start with aquafortis if working with curly maple. It really makes the grain pop. I strongly recommend you experiment on some scrap of the same species of maple as your stock - preferably off-cuts from your stock blank. Staining is often a one way street and poor choices can lead to unpredictable and/or disastrous results.
 
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