QUESTION 4
(a) List any five methods of assembling leather parts.
(b) Explain any five factors to consider when selecting adhesive for leather projects.
This question was very popular among candidates, most of who scored above average marks. The (a) part of the question required candidates to mention the methods of coupling components of leather articles; and the (b) part required candidates to provide detailed answers on the factors to consider when selecting adhesive for leather projects.
Candidates were expected to answer thus to score maximum marks:
(a) (i) Stitching;
(ii) Lacing;
(iii) Tonging;
(iv) Riveting;
(v) Gluing;
(vi) Eyeleting;
(vii) Use of grommet;
(viii) Use of studs;
(ix) Tacking;
(x) Stapling.
(b) (i) Type of Material
Depending on the type of material, specific adhesive is needed to achieve good bonding effect.
(ii) Viscosity
Depending upon the method of applying the adhesive whether by brush or by any other means, the viscosity and solvent system must be taken into consideration.
(iii) Evaporation/ Drying rate
The solvent in the adhesive must evaporate quickly for rapid tack development.
(iv) Tack retention/ Bonding
Tack retention must remain as long as possible for perfect bonding.
(v) Standard condition
For high bonding strength, the performance of the adhesive and other conditions e.g. heat, water and flexibility must be considered.
(vi) Surface compatibility
The type of leather to apply adhesive to must be considered because certain adhesive may not perform well on certain leather e.g. neoprene. Some adhesives are not compatible with leather and polyurethane soles.