This especially formulated gelcoat is the beginning of theĬoating which will eventually give the polished surface from which the mould will be lifted. This process of hand finishing is repeated until the foreman considers the plug smooth enough to Likewise, any irregularity which spoils fairness can be removed by grinding or by hand sanding. Remove the shallow indentations which will show up once the FRP skin is consolidated. This layer can then be filled where necessary with resin putty to Plug with a layer of FRP as soon as the crude shape of the vessel is achieved to reduce distortionĭue to any shrinkage of the wood. At the deck edge which is in this case near the floor while the keel is someĭistance above it, a plywood flange is attached so that later during the moulding process, gelledįRP can be trimmed back to leave a solid laminate with a clean cut edge. The skeleton can be strip planked or completed in any material judged suitable to achieve the shape This is usually a heavy wooden frame laid on a level concrete floor. To begin, the frames of the plug are erected in an inverted position on a solid foundation. It will be used once and thrown away.įigure 27 Polished surface of new mould 8.1.1 Hull plug and mould building It needs to be made clear once again that the plug is NOT a boat but a means to building a Terms of sheen, smoothness to the touch and fairness of hull lines.Īchieving the finish in FRP once the basic woodwork has been completed. A mirror finish is often quoted and this is true in Even though the plug is virtually a wooden hull, for reasons ofĪccess and mould release it is better built in this position.įinishing the surface to a high standard. Three aspects need particular attention for the construction of a good plug:īuilding the plug upside down. This aspect is particularly relevant in developing countries where a conservativeĪpproach to new demands leads to slow progress and requires constant encouragement by an experienced Though traditional skills are required, ifĬarpenters have not built a plug before new demands will be made in terms of accuracy and quality of Wood is the principle material for construction but foam or balsa can be used as wellĪs other less common materials such as C-Flex. In the case of a new vessel design construction of the plug calls for the traditional skills of aīoat builder. The principles described for the construction of small plugs and moulds equally apply to large. Single skin construction using the PLUG - MOULD -HULL sequence is the simplest and cheapest method to build a number of boats from the same mould. Proportion of the FRP vessels existing today. This chapter deals with the most common method which has been used to produce a large

Fishing boat construction: 2 Building a fibreglass fishing boat

Wooden ship construction