WAEC 2016 Auto Body Repair & Spray Painting Past Questions and Answers (Paper 2&3), WAEC 2016 Auto Body Repair & Spray Painting Past Questions and Answers (Paper 2&3)
(a) Explain what the technician, illustrated in the sketch above, is doing.
(b) (i) Name the tools labeled X, Y and Z. (ii) State the purpose each of X and Z.
(c) State three safety precautions that should be observed by the technician.
The few candidates that attempted this question did very well. Since a greater section of the candidates did not attempt the question, it is believed that they had just little or no knowledge of what the task is, or they simply found other questions easier. Here are the solutions.
(a) The technician is removing a broken drill bit from a drilling machine.
(b) (i) X : drift
Y : hammer
Z : drill bit
(ii) X: It contacts the drill bit and pushes out the bit when tapped with a hammer.
Z: It does the cutting or drilling of hole in the work-piece.
(c) Safety Precautions
- – Safety goggles must be worn.
- – The drill shank and taper sleeves must be kept free of burrs and grit.
- – The technician must wear a hand glove to hold the drill bit for removal.
- – The hammer must have a good handle.
- – Safety boots must be worn.
(2) (a) State the purpose of each of the following heat treatment processes: (i) Tempering; (ii) Normalizing.
(b) (i) What is a ferrous metal? (ii) List two types of steel used in auto body construction.
(c) State two differences between oxygen and acetylene cylinders used in gas welding.
The Candidates did well on this question number. However, some of the candidates could not satisfactorily answer the questions asked in 2(b)(ii) and (c).
(b) (ii) Two Types of Steel Used in Auto Body Construction
- – Carbon steel;
- – Alloy steel;
- – Cold-forming steel;
- – Free-cutting steel;
- – Spring steel;
- – Rust-resistant steel;
- – Stainless steel.
(c) Two Differences between Oxygen and Acetylene Gas Cylinders
- – Oxygen cylinders are painted black or blue while acetylene cylinders are painted maroon or red.
- – While the valves of oxygen gas cylinders are right threaded, those acetylene gas cylinders are left threaded.
- – Oxygen gas cylinders have smaller diameters.
- – Oxygen gas cylinders are longer.
- – The hose of oxygen cylinder is painted black, while that of acetylene cylinder is painted red.
(3) (a) (i) List two classes of accident. (ii) Explain each of the classes listed in 3(a)(i)
(b) State two important areas where aluminium is used.
(c) List two important machines used in auto body repair
The Candidates did well on this question number. However, some of the candidates could not satisfactorily answer the questions asked in 3 (c).
(c) Three Machines Used in Auto Body Repair
- – Jack
- – Guillotine
- – Chassis alignment jig
- – Wheeling machine
- – Pneumatic sanders
- – Spraying machine
- – Rolling machine
- – Drilling machine
- – Swagging machine
- – Cone-rolling machine
(a) (i) List three types of vehicle body construction
(ii) Explain two of the types listed in 4(a)(i).
(b) State three merits of mild steel.
The Candidates did well on question 4 (a) but could not satisfactorily answer the questions asked in 4 (b).
(b) Three Merits of Mild Steel
- – It is easily welded together.
- – It is very cheap.
- – It is very durable.
- – It is always available in various forms
(a) List three constituents of paint.
(b) State two causes of spray fog.
(c) With the aid of a sketch, show: (i) correct spray pattern; (ii) heavy centred pattern.
(a) Three Constituents of Paint
- – Pigment;
- – Binder;
- – Solvent (thinner) and
- – Additives.
(b) Two Causes of Spray Fog
- – Over atomization of the paint
- – Too thin a paint
- – Wrong use of spray gun
(c) The Sketches of Correct and Heavy-Centred Spray Pattern
The following materials were supplied:
(a) mild steel sheet metal 300 mm 220 mm 18SWG;
(b) mild steel sheet metal 300 mm 220 mm 18 SWG;
(c) mild steel bracket 120 mm 60 mm 18 SWG and
(d) one tie-on label.
The sketch below shows the assembly view of a longitudinal runner joined to a chassis frame by a bracket. Using the materials supplied, produce the component.