Once a tree is felled, where is it transported?
What process takes place here?
Once a tree is felled, it is transported to a saw mill. Here, the process of conversion takes place.
What is the definition of Conversion?
Conversion: when a tree log is converted into timber of useable size.
What are the four main reasons for Conversion?
Reasons for Conversion:
- It allows wood to dry faster.
- It produces wood of useable size and shape.
- The quality of the timber can be viewed and evaluated.
- It reduces defects in timber.
What are the three methods of conversion?
Methods of Conversion:
- Through and through sawing
- Tangential sawing
- Quarter sawing
What do you do in through and through sawing?
In through and through sawing, the log is cut lengthways or parallel to the grain.
What do you do in Quarter Sawing?
Quarter Sawing: this method involves cutting the log into quarters first, and then making cuts towards the centre of the log.
What do you do in Tangential Sawing?
During Tangential Sawing, the log is cut at a tangent to the annual rings of the log.
4 Advantages of Through and Through Sawing…
4 Advantages of Through and Through Sawing:
- Simplest and cheapest method of conversion
- Very little waste
- Fast
- Widest possible board is obtained
4 Disadvantages of Through and Through Sawing…
4 Disadvantages of Through and Through Sawing:
- Boards tend to cup
- Grain pattern is not considered to be attractive
- Boards not as durable or strong as other methods of conversion
- Cannot be used as structural timber in a house
Cupping happens with a large amount of _______
Cupping happens with a large amount of sapwood.
3 Advantages of Quarter Sawing…
3 Advantages of Quarter Sawing:
- Strong and durable boards
- Stable boards, unlikely to cup or shrink
- Very attractive grain pattern, especially in oak wood
4 Disadvantages of Quarter Sawing…
4 Disadvantages of Quarter Sawing:
- Expensive
- Takes a lot of work and time, as the log must be turned over after each cut
- Narrow boards produced
- A lot of waste produced
3 Advantages of Tangential Sawing…
3 Advantages of Tangential Sawing:
- Very strong durable boards produced
- Boards will not split easily with nails
- Flame figure grain pattern produced
5 Disadvantages of Tangential Sawing…
5 Disadvantages of Tangential Sawing:
- Expensive
- Takes a lot of work and time
- Boards can cup and shrink
- Majority of boards are quite narrow
- A lot of waste produced
