The boat construction entails different methods that are all precise to come up with the best fibreglass boat. However, all boats are constructed in using a general mold known as the female mold. First, there is a release agent that is applied on top of the mold. It is then followed by the gelcoat material which is applied on top of it. The thickness of the gelcoat ranges between 12-22 mils thick. It is an unsaturated, pigmented polyester resin. It is meant to provide a cosmetic, smooth, glossy finish and it also acts as a moisture barrier hence prevents the coat from absorbing moisture. This makes it the best for boat detailing. On top of the gelcoat are some subsequent layers of fabric that are saturated with resin. The lay-up schedules depend on the number of boats constructed. A typical hull section may consist of the layer of woven roving and several alternative layers of mat, the layer of gelcoat and a core material such as end grain foam or end grain balsa. This is followed by several more forms of alternating layers of woven roving and saturated mat.
However, the hull thickness varies from boat to boat. In the older days, boats were being coated with a fibreglass thickness of 3.8cm (1 ½”) to 12.7cm (5”). This was placed in the keel areas of boats which were built with more heavy weight. Nowadays, the trend is that, instead of increasing the thickness, it is being reduced to a thinner layer. Therefore, this makes the integrity of the laminate components used very critical. The force of gravity plays a big role in boat construction since the standard lay-ups rely on it to hold all of the saturated resin material in place until they get cured.
The vacuum bag laminating technique allows the constructor to evenly compress the entire wet-out laminate in the mold. This technique has seen the composite construction rapidly advance since it also controls the strength-to-weight ratio and the resin content of the laminate. Well, the wood is used in both secondary and primary structural features such as the frames and stringers, bulkheads, trim, blocking and core material. After the shell is laid up, the bulkheads, stringers and other interior features are bonded. It is important to note that most of the fibreglass boat repairs involve the use of wood and the problems causing polyester material from bonding easily with wood.
The other thing you should not is that, the terminologies used to define the wooden boats are different from the terminologies used to define the fibreglass boats. However, where the wooden boat components serve the same function as the fibreglass components, they share the same names. On the other hand, manufacturing methods and materials vary from manufacturer to manufacturer, from sail to power and from small boats to large boats.