Definition of seasoning of Timber
The process of removing moisture or sap from freshly cut timber is known as seasoning of timber.
The following two methods are used for seasoning of timber.
Natural seasoning or Air seasoning
Natural seasoning as the name suggest is the natural way of removing moisture from timber. This method is cheep but it takes time. It requires about 60 to 90 days for soft wood.
When the timber is freshly felled or cut, it should be place at a place where air may circulate through it. But it should not be exposed to sun and wind. Time required for seasoning of timber depends on the surface exposed to the air. There should be equal dry of timber by turning the pieces frequently. Timber pieces should be kept free from the ground and other damp conditions.
Evaporation of moisture is greater from the ends than from sides. And evaporation is also greater from the upper side than lower side.
Duhamel says that the moisture quantity which is evaporated from the fresh green oak is about one third or two third of its weight. The proportion may vary according to wood type and quality and also on the nature of the soil.
It has been shown by the experiments of Duhamel that timber looses 1/3rd of its total weight when it is kept for drying.
If we want to use timber for the purpose of carpentry, It should not be used for almost two years after it is felled. Others method may be used but for the carpenters work, natural seasoning should be the preference.
Artificial seasoning or kiln seasoning
It is the quickest method of wood seasoning and keeps the moisture contents of timber under control. The seasoning by this method generally takes four to five days under normal conditions.