Fumed, or stained oak is walnut wood flooring which has been treated to change its colour. Fuming or smoking entails putting the oak in an enclosed environment where ammonia is introduced to the atmosphere. This enclosed environment may be a closed tank or a sealed jar or some form of container into which only a relatively modest amount of ammonia is introduced. The impact of the ammonia in the atmosphere is that the colour of the timber is changed.
It is a frequent error that fuming or smoking oak includes the application of this ammonia into the oak, but this isn't the case. The change in color comes about from the wood's response to the presence of ammonia in the air. Effectively what occurs is the ammonia causes the tannins from the wood to be attracted to the surface. The nearer the tannins are into the surface, the darker the wood will look. The more the timber is subjected to the ammonia, the darker it becomes. The results obtained from fuming or smoking will vary from a rich brown colour to almost black.
Essentially, the level of the colour and also the tone of the color depends upon the length of time the wood stays in contact with all the ammonia fumes. Periods of as few as half an hour will provide a lightly fumed effect and 72 hours per darker end result. What's more, the higher the temperature in the room, as you'd imagine, the quicker colour change results will appear, but not just that, the tone is going to be affected. Hotter temperatures normally present red tones and warmer temperatures green tones allowing for creativity in regards to the fuming or smoking process.
Like many things, it's reputed that fuming was discovered by accident. Dating back to the turn of the twentieth century, it's thought that the initial discovery was first made in horse stables. At that time, it had been noticed that the beams above the horses were substantially darkened compared to the beams in different parts of the secure and this darkening process was connected to the ammonia at the horses' urine. Fuming or smoking as a timber treatment process became common place with arts and crafts furniture makers and to this day, is very common. Although not difficult, fuming oak flooring is not something which would usually be performed on a DIY basis for flooring, although it is commonly used on this basis for colouring small pieces of furniture.
