I don't remember the nitric versus the hydocholric acid (although I do remember my hands turning brown from pure nitric acid). But I do remember that a fine furniture man, Mario Lauria, used a dilute mix of Potash - which I think would make a nitric acid - to turn the wood without stain. We made a bartop of Mahogany (white, in the natural state) and turned it into a fine deep reddish with the Potash (and it wouldn't burn with cigarettes, as there was no stain to burn). Hope this helps.
Best, Jon > Is nitric or hydrochloric acid( I forgot which) which you wet the wood with > then apply heat and it turns the wood brown (or green if you are unlucky) use > dilute. I used on a rifle stock and by the time I was done it was too dark. > As I understand it it works on maple (sycamore to you UK folks) and reacts with > the sugar in the wood.
