Moulds for production boats
In response to a recent mystery photo, we introduced you to the different types of moulds and more specifically a wooden mould for the construction of a unitary pleasure boat. When the series are large and the shapes complex, it is necessary to have a robust mould that will not deform over time. The method presented above proves to be insufficient and the mould itself is then made of a well-structured, high-sampled composite. But if it is in composite, it will be necessary to mould the mould on another mould? No one comes out of it anymore, you might say! This is where our new part comes in: the preform or mother part.
Reproduce the outer shape of the shell in foam loaf form
Once the boat has been designed, the shipyard or its architect will work on the design of the tools. Modern tools make it easy to create the digital hull geometry file. With the help of a milling robot, polystyrene blocks like those in our mystery photo are machined. They then form a kind of gigantic lego!
They are then assembled and sanded again for good continuity of shape. Sanding can be manual or automated depending on the parts, the job site and its budget.
Once coated, the master part is brought to a mirror polished surface. Its shine allows a visual inspection of the defects with light. A laser dimensional inspection can be carried out at this stage. The respect of shapes is essential to guarantee the quality of the final parts and their good assembly. The mother part or preform is then finished.
The mould or moulds necessary for the mass production of boats are built on it.
Restoration of old boats
In some cases, preforms may disappear or be destroyed. It is then possible for restoration projects to use the hull, deck, roof or any old part of the boat as a preform. By making an impression on the existing part, the necessary male or female mould is obtained, ensuring its good rigidity. The restorer, professional or amateur yachtsman, can then make a new part while respecting the geometries.
