Building a custom boat takes an average of 18 months, depending on the size of the boat. It is a long process that includes at least 7 steps from the receipt of the order to the delivery of the final product. Within this framework, it is important to know that different processes can be used to manufacture the parts and the hull of the boat, including infusion molding.
In this article, we will focus on the stages of custom boat construction and especially on the molding processes of the parts.
1st step: The preliminary design study
Like any other construction project, the building of a boat requires a study to determine the elements that will make up the final product. The preliminary design study will define the plans of the boat, its external and internal characteristics, its final design, etc. This study will be carried out according to the client’s needs and with an architect, as well as the specialist in charge of the construction. The expertise of these professionals is essential as the boat must be manufactured in compliance with the safety and environmental standards laid down in the regulations in force, the specific standards relating to the place where it will be used and the final use. A commercial proposal will have to be drawn up at the end of this study.
2nd step: The industrialization study
Once the architectural plans are in hand, they will be used to design the plans for the construction of the boat. The latter will be useful to define the means necessary for the production of parts, handling, and sampling of the structure. The elements of the structure include bulkheads, panels, and other parts of the work.
Raw materials and flame-cut parts will then be ordered and received for assembly.
Step 3: Hull construction
In practice, the boat’s hull is made by molding the parts. In order to obtain large and solid elements, it is customary to opt for composite materials and to use a particular process: infusion molding.
How is the hull made using the infusion technique?
The infusion molding technique consists of injecting a low-viscosity resin inside several layers of dry superimposed glass cloth. The whole is then stored under vacuum using a flexible membrane placed in a mold. Vacuum storage will ensure that the glass laminate is perfectly compacted. This process is particularly advantageous in shipbuilding, as it allows large parts, such as the hull of the boat, to be infused in a single block.
In addition, this technique allows the composite to be optimized and its weight increased. It is quick to make, which saves fuel.
Finally, even if it is preferred for the molding of large parts, it is important to note that infusion also makes it possible to design smaller parts.
Other types of molding
Although the infusion technique is the most popular in shipbuilding, other methods can also be used, including contact molding. This technique consists of applying polyester resin to a strip of glass cloth using a roller or a special brush. The product should be applied until the fibers are fully impregnated. Then, the air bubbles contained in the impregnated glass cloth are removed with another brush called a “debubbler” to preserve the isotropy of the laminate and its mechanical characteristics. This technique is particularly suitable for the manufacture of small parts as well as surfaces that cannot be treated by simultaneous spraying.
Simultaneous spraying is another process that consists of directly spraying cut glass wire from a spool. This requires the use of a spraying machine equipped with a compressed air gun and rotating knives. The fiberglass is then sprayed, cut and mixed with a catalyzed polyester resin so that it is ready for debubbling. This method has the advantage of giving a homogeneous mixture.
For small parts, it is also possible to use the low-pressure injection technique. This consists of molding the glass reinforcements and then injecting a special polyester resin under pressure. Air bubbles are eliminated under pressure by means of vents placed judiciously on the molds.
4th step: Assembly
Assembly is the stage during which the various parts that have been molded are put together, including the outer hull and the compartments. Assembly can be done by welding.
5th step: Armament and layout
At this point, the hull of the boat and the decks will have been fitted. The hull will then be painted and the final finishing work will be carried out: masonry, insulation, piping, electrical and mechanical installation, etc. This stage will also see the installation of all the equipment used on the boat.
6th step: Launching
In order to finalize the bottom welds and paint the underwater part of the structure, it is necessary to launch the boat. To do this, the boat will be shifted from the marble to the shore pulling carriages and then pulled into the water.
This step is carried out according to a well-established ceremony during which a bottle of champagne will be burst on the hull of the boat before it is actually launched. The boat thus christened and arrived in the water will then be celebrated with horns and a foghorn to mark the first launch.
At the end of the ceremony, the boat will be tested in the presence of clients and experts to detect any defects and correct them later. The final finishing touches can be made to the turning of the structure and the engine.
Finally, the boat will be delivered to the client according to the terms and conditions set out in the contract.