Question 7
(a) Explain each of the following timber defects:
cup shake;
twist.
(b) (i) Sketch a galvanized roofing nail.
(ii) List two types of screw.
(c) (i) State three characteristics of Abura timber.
(ii) (ii) State two reasons for lipping a plywood table top.
Observation
- The explanation of the different defects is to an extent encouraging.
- (i) The drawing of a galvanized roofing nail is very good.
(ii) They were able to list the two types of screw expected.
- (i) In stating the characteristics of Abura timber, the students were given different types of responses narrowing it to characteristics of hard amd soft wood.
The expected response to question 7 (c) (i) is as given below:
- Seasons very well
- Take finishes well
- Easily worked on
- Takes adhesive very well
- Has straight grain
- Fairly resistant to acid
- Good for making veneer
- It lacks pronounced grain marking
- It has a pleasant surface texture
(ii) The students responded very well to this question lipping a plywood table
top.