Seasoning of timber

Mechanical Engineering

Seasoning of timber:

The purpose of seasoning of timber is to remove the excess moisture content in the wood to make it suitable to be used for various purposes. Excess moisture content of the wood can result in uneven shrinkage, warping, twisting etc.

Advantages of Seasoning:

  • Wood becomes hard and durable.
  • The density of wood gets reduced and hence the workability of wood is improved.
  • Defects like warping, twisting, splitting and shrinkage do not occur.
  • Wood can be easily polished and painted.
  • Its resistance to fire, shock and stresses is increased.

Methods of Seasoning:

Natural or Air Seasoning– A platform is constructed on the ground and a shed is made on this platform. The balks of timber are arranged in the shed in such a manner that free circulation of air takes place through them. The balks are not directly exposed to sunlight. To accelerate the rate of drying, the balks are periodically turned upside down. Harder wood takes more time to get dried as compared to softer wood. The time taken for seasoning can be from 1 to 5 years depending upon the type of wood.    

Water Seasoning– To remove the sap of the wood, the timber balks are immersed in flowing water for 2 to 3 weeks. The water takes the sap of the wood with it. The timber is taken out of water and its air seasoning is done by keeping it on a tapered platform.

Artificial or Kiln Seasoning– It is the quickest process to dry the wood. The timber balks are arranged on big trolleys to drive them to oven or kiln. The timber balks in kiln are kept under controlled conditions of temperature and humidity. The wood obtained by this method is of inferior quality as compared to natural seasoning. The capital required is also more as compared to other methods.   

Other methods like Electrical and Chemical Seasoning are also used for seasoning of timber.