It is very easy to scorch the wood when heating it. AF stain will not turn wood black rapidly unless very (much too) strong.
Most of the time I use an electric paint stripper on LOW to react AF.
But its easy to have "issues" without careful use and care at the sharp edges or relief carving. Use on "high" is even worse.
I have simply put them behind the wood stove in winter and turned as the color came up.
The key is to heat the wood deeply as with radiant heat. While the paint stripper looks kinda like a hair drier it uses radiant heat and the airflow is mostly to keep the elements cool. It will heat wood deeply is used right.
The old way was to heat a bar of iron in the forge and pass it over the wood.
But this can burn wood too.
Heating the wood deep enough to react all the stain is important. Thus gas burners and propane torches usually do not work well in the long term. The stove burner will work but requires CAREFUL USE and keeping the wood well away from the flame not trying to rush the job. Quick heating with a flame can result in unreacted acid turning the stock green.
I use warm water with all the baking soda it will absorb to neutralize.
I would also point out that the stocks I have done with commercial AF stain have "browned" considerably in 10 years or so. I attribute this to the Nitric being mixed with Hydrochloric.
Diluting store bought stain is not the answer. If it is thought to be too acid simply add a couple of de-greased nails (or wire or steel wool) this will add iron to the solution and deplete the acid. This can be continued until the solution is very very weak. The stain does not have to be acid to work.
The "advantage" to the dye type stains is that you can put them on and the stock is stained in most cases. But to get them to look good usually takes more work than AF and then the stock looks like it was stained with a modern stain in far too many cases.
I like AF on maple and see no reason to use anything else except the the case of repairs on finished stocks or other such things that can sometimes result in "jumping through hoops" to match the color.
In processing
Green after staining
Reacted with 2 coats of finish.
This stock was stained heavily allowed to dry for an hour or more, reacted and neutralized with baking soda water.
Dan
