Section 1 General

101. Application The requirements

lay-up method or

in this chapter are framed for the case where FRP is moulded by the hand spray lay-up method. The moulding methods other than those mentioned above

are to be in accordance with the discretion of the Society.

102. General

1. Manufacturing premises are to be so equipped and arranged that the material supplier's directions for handling the materials, the laminating process and curing conditions can be followed.

2. The air temperature in the moulding shops is not to be less than 18 ℃. The stipulated minimum

temperature is to be attained at least 24 hours before commencement of laminating, and is to be maintainable regardless of the outdoor air temperature.

3. The temperature in the moulding shops is not to vary by more than ±3 ℃ during 24 hours.

4. The relative humidity of the air is to be kept so constant that condensation is avoided and is not to exceed 80 %. In areas where spray moulding is taking place, the humidity is not to be less than 40 %. The stipulated air humidity is to be maintainable regardless of outdoor air temperature and humidity.

5. Air temperature and relative humidity are to be recorded regularly. In larger shops there is to be at least on thermohydrograph for each 1500 mĪ where lamination is carried out. The location of the instruments in the premises is to be as neutral as possible.

6. Draught through doors, windows etc. and direct sunlight is not acceptable in places where lami- nation and curing are in progress.

7. Manufacturing premises are to be kept clean and as free of dust as possible, so that raw materials and moulds are not contaminated.

8. The ventilation plant is to be so arranged that the curing process is not affected.

9. Sufficient scaffoldings are to be arranged so that all lamination work can be carried out without operators standing on the core or on surfaces on which lamination work is taking place.

10. During lamination of large constructions the temperature should be recorded at least at two levels vertically in the workshop and the curing system should be adjusted to compensate for possible temperature differences.

11. Fabrication of flat panels are to be carried out on a support lifted from the workshop floor level.

103. Blending Proportion

1. FRP yacht manufacturers are to submit details of material types, material manufacturer and mixture ratio of materials for approval before manufacturing.

2. In mixture of all materials used in resin, the items not specified in these requirments should follow the manual of manufacturer and all materials shall be measured accurately and mixed sufficiently.