Fig. 10 shows two methods of converting a log into usable timber planks. The timber has been selected for its working properties and appearance. Different t...
Question 1 Report
Fig. 10 shows two methods of converting a log into usable timber planks. The timber has been selected for its working properties and appearance. Different types of timber have different characteristics that affect their suitability. The grain direction and moisture content affect how the timber can be worked.
The lid lifts up and down. The shape is good. The grip stops it from slipping.
The cast iron used gives the product good toughness and electrical conductivity. The designer considered sustainability and cost of materials when selecting materials.
(a) Name Method 1 and Method 2 of timber conversion shown in Fig. 10. [2]
(b) State one advantage of Method 2 over Method 1. [1]
Answer Details
(a) Naming the two methods of timber conversion:
- Method 1 is through-and-through sawing (also called plain sawing or slab sawing). [1] In this method, the log is cut into parallel planks with a series of straight cuts all running in the same direction across the full width of the log. This is the simplest and most economical method because it produces the least waste and the fastest cutting rate.
- Method 2 is quarter sawing. [1] In this method, the log is first divided into quarters, and each quarter is then sawn so that the cuts are roughly perpendicular to the annual growth rings. The radiating pattern of cuts shown in the diagram is characteristic of this approach.
(b) One advantage of Method 2 (quarter sawing) over Method 1 (through-and-through sawing):
Quarter-sawn timber is less likely to warp or distort during seasoning and in use. [1] Because the annual rings run more nearly perpendicular to the face of each board, the timber shrinks and expands more evenly, resulting in greater dimensional stability. Quarter sawing also produces a more attractive, even grain pattern on the face of the board.
Download The App On Google Playstore
Everything you need to excel in your exams
