I found this hardware store, as strong domestic cleaning ammonia. This is about 20% - 25% and perfectly adequate for overnight or 24 hour processes.
Supposedly you can also find ammonia in a drafting or technical draawing supplier. No doubt this was available once (it was part of a process for duplicating blueprints) but I've not found it there in recent years.
Don't use anhydrous ammonia. That's really nasty stuff; highly toxic and unneccessary.
You'll also need a couple of small flat dishes, to put the ammonia in. These should be plastic - I use take-away trays. Don't use metal, especially aluminium foil ! Ammonia is corrosive to aluminium, sufficiently so to eat a hole through the bottom of a tray.
Safety gear
Ammonia is noxious, but it's quite easy to control. It's not essential (with only 25% ammonia) to use a mask, but it makes it more pleasant. Ammonia dissolves easily in water, so it's important that your mask has eye protection, or you might as well not bother. The mask should use filter cartridges suitable for ammonia, but a basic charcoal vapour filter will reduce the nuisance. Dust filters and paper masks aren't any use though.
I also found this link
http://www.forestryforum.com/board/inde ... #msg645278
Also Ammonia Fuming
Ammonia Fuming is a process in which white oak is exposed to the fumes of anhydrous ammonia. The fumes react with the tannins in the wood, which produces a gray color on the surface of the wood. When treated with Watco Danish Oil, the wood turns a deep brown color.
This process was developed by Gustave Stickley for the Arts and Crafts furniture he made and sold, as a way to approximate the coloring of English Brown Oak, which is not avavilable in the United States. It is still used today by furniture makers who want to replicate the look of turn-of-the-century Arts and Crafts furniture.
A note of warning: Ahnhydrous Ammonia is EXTREMELY DANGEROUS. It is very caustic and must be handled with care. ALWAYS WEAR A RESPIRATOR WHEN HANDLING THIS CHEMICAL! Household ammonia is usually .5% - 3% ammonia to water. Anhydrous Ammonia is 23%. The fumes are really strong, so it should only be opened in a well ventilated area. This does not include your kitchen. Anhydrous Ammonia can be obtained from Blueprint Supply websites. it is only available by the gallon, and requires a $20.00 hazmat handling fee.
That said, nothing in the world looks as good as fumed white oak. I have not yet found a combination of finishes that really matches it.
To fume oak, build an airtight tent around your object with plastic dropcloths. I like to try to use a clear plastic so I can check on the progress without having to open the tent. Pour about 1/4 cup of anhydrous ammonia into a glass container, place it in the tent, and seal the tent completely. Dedending on the size of the piece, and the roominess of the tent, you will probably have to wait between five and twelve hours. My experiments have show that after about twelve hours, there is not a significance in color change.
To dispose of the ammonia, mix it thouroughly into five gallons of tap water. This will dilute it enough that it can be poured down the sink.
Do not sand the work after you fume it, as you will sand off the top layer of the wood that has reacted with the fumes, and it will look like white oak again.
You can use this process with other woods, but you have to brush on tannic acid, so the fumes will have something to react to. I have not really liked the colors as much when I use this on anythign other than white oak.
Italic textFine WoodworkingItalic text Magazine has a couple of articles about this process that are a little more specific.
There is loads of it Neil I just googed it
