Observation

All the candidates that attempted this question did not do that satisfactorily. The solution of the question is given below.

(a) (i) Means of Preventing Porosity of Weld

- Contact between electrode and water should be avoided.
- The surface of the parent metals must be cleaned of oil,paint, grease, rust and moisture.
- Appropriate arc length must be used.
- Wet electrode must be dried before being used.
- Appropriate welding flame must be used.
- Too high welding current must not be used.

(ii) Means of Preventing Slag Inclusion in Weld

- Correct welding technique must be used for the job.
- Appropriate travel speed must be used.
- The right type of electrode flux coating must be used.
- Damp electrode must not be used.
- Too low welding current must not be used.
- Joints/surfaces must be cleaned before being welded.
- Slag must be removed before making another run.

(b) The Tool Used to Remove Slag from a Weld
Chipping hammer

(c) SAFETY Precaution Observed While Working on a Bench

- Horse play must be avoided.
- Tools must be used by their handles.
- Right tools must be used at all times.
- While working, distractions must be avoided.
- Safety gadgets must be worn at all times.
- Bench must be kept clean.
- Cutting/marking tools must be carried with their cutting/marking edges pointing backwards.
- Tools must not be thrown to one another.
- Tools should not be placed at the edge of work benches.
- Workpieceto be held firmly on the vice before being worked on.

(d) (i) Components of Duralumin
Copper, Aluminium, Magnesium, Silicon, Zinc and Manganese.

(ii) Components of Bronze
Copper and Tin

(iii) Components of Brass
Copper and Zinc