Tung oil is a drying oil which derived from the nut of the tung tree. The seed of the nut is pressed to produce the oil. As a drying oil, tung oil hardens and produces a transparent, plastic like finish.
Tung oil seeps into the wood grain, giving it a perpetual wet look which accentuates the grain. The wood is slightly darkened by the oil and it has a warm, rich look to it. It provides a relatively hard surface, when intact, that provides a waterproof finish that is impervious to dust, alcohol, water, acetone, and various acids.
The advantages of tung oil are:
- Waterproof (as long as water does not sit on the surface too long)
- Resistant to alcohol
- Resistant to acetone
- Resistant to vegetable and fruit acids
- Flexible. Maintains its protection with the expansion and contraction of wood
- Accentuates the texture and grain of the wood
- Easy and very forgiving to apply
- Easy to re-apply when surface is damaged.
- Non-toxic and food safe
The disadvantages of tung oil are:
- Pure oil has a long drying time
- Not scratch or abrasive resistance
- Can have a slight odour that may last a few days to a few weeks.
- It can be difficult to store
- When storing if a film starts to form in container or gummy deposits are around the edge of the container, the whole batch has to be discarded.