For FRP to cure some form of heat is needed. This is conventionally achieved by the addition of a catalyst to the accelerated resin. It should be understood that if the resin is treated exactly as instructions for European or North American use dictate, then very short gelling times are likely. This is because the resign is well into its shelf as it has been in transit probably for months and because of the higher ambient temperatures of tropical countries. Each batch of resin should be tested to find an acceptable gelling time by fabricating a test panel typical of laminates in day to day use at the yard.
Sea Fish Industry Authority Laminate Schedule
|SCANTLING NUMERAL||WEIGHT grammes/ metres2||WIDTH millimetres||WEIGHT grammes/ metres2||WIDTH millimetres||WEIGHT grammes/ metres2|
An extreme example of water content/humidity is that of a piece of reinforcement dropped into water which becomes soaked. This piece would obviously be rejected. Yard management should be just as aware of the possibilities of weak laminates if moulding is carried on in conditions of high humidity. Relative humidity of 80% is the maximum recommended level which may be temporarily tolerated and precautions should be taken when 70%–95% is experienced during certain times of the day or seasons of the year. This may mean ventilating or dehumidifying the moulding shop, moulding only during the cooler times of the day or arranging annual production so that moulding work is not undertaken during, for instance, the monsoon season. A hygrometer in the mould shop should be monitored and a record kept of daily humidity levels.
In a developing country it is rare to have regular access to foreign currency for the purchase of imports. As boatbuilding in FRP would be dependent on imported raw materials and in the beginning an inexperienced workforce, it makes sense to keep imports down and technology at an appropriate level. That is, to be self reliant and do without complicated equipment which may need many spare parts. Materials described so far have been basic but still demand substantial technological appreciation and a technology jump when compared to traditional wooden boatbuilding. A labour intensive approach is appropriate with overmanning compensating for any lack in productivity.
Simple tools are adequate for the main part, with some specialized containers required for dispensing catalyst and other imported hand tools for spreading resin during the laminating process. These are not expensive nor do they need maintenance beyond cleaning.
When the laminating process is complete hulls and decks are released from the moulds and require fitting out as do traditional vessels. At this stage traditional carpentry skills will be needed as cutting and drilling FRP is similar to wood. It is now that a source of electricity will be useful for fixed and hand power tools.
It is a common error to be over-impressed by a new hull being released from a mould and believing that the vessel is almost finished. This is far from reality and traditional boatbuilding requirements during the fitting out stage should not be underestimated when switching to FRP construction. In some boatyards in northern countries FRP hull shell costs for larger vessels are considered as low as 10% of total costs which emphasizes the amount of work needed to convert an FRP moulding into a completed vessel.
The setting up of a new FRP boatyard in a developing country will probably be at the request of a government department who foresees the need for an alternative source of vessels. Once external expertise has advised on outline planning of site, choice of vessel, market analysis, etc., construction or extension of the boatyard should take place as design selection and tooling-up for production. Assuming some external expertise has been present to guide the development of the FRP boatyard, towards the end of this phase the point will arrive where staffing and managing the yard will have to be addressed. It is usual in these circumstances to recruit carpenters or boatbuilders as their work experience is probably the most relevant to FRP construction. It is also usual that early on in the life of the yard a natural division of labour takes place where the more skilled carpenters concentrate on the fitting out and woodworking aspects of construction while the less experienced become full time laminators. There is also a tendency for older workers who are used to relatively clean woodworking to decline to use the strong smelling and messy FRP materials. For a yard employing a shopfloor staff of about 30 people, which will include 2–4 charge hands or section leaders, the management structure may contain an overall general manager, a secretary/clerk, an accountant and a foreman.
Management skills will not be discussed here but the Manager in overall charge should have an awareness of his product at the outset and would benefit from exposure to FRP construction which may require secondment to a boatyard abroad. Likewise the foreman must be thoroughly trained in all technical aspects of FRP construction which will require a longer period of training either abroad or under the guidance of an acknowledged expert at the new boatyard. This technology transfer is most important. The “know how” required for the day to day running of an FRP boatyard is a valuable asset but can be wiped out with serious consequences for the yard if the technicians are insufficiently trained or if the knowledge is concentrated in one person who may return, for example, to his village at a moment's notice. The training effort should be concentrated on the practical use of FRP with “hands-on” experience gained by the trainee laminator before he is allowed to work on a real boat. Carpenters and mechanics can be expected to fit out a hull in a conventional manner once some wood has been attached to the moulding.