Plastimo welcomed us to its site in Lorient. We took the opportunity to discover the different stages of the production of navigation compasses, essential safety equipment at sea. He has contributed to the brand's reputation, with more than 4 million instruments sold since 1968.
Sapphire for boat compasses
Seen from a distance, the navigation compass seems to be an extremely simple part. However, a few crucial parts guarantee its quality. The manufacturing process begins with the preparation of the various parts received from subcontractors. The plastic elements, wind roses and supports, are mounted with the red direction marker and magnets. Plastic injection is carried out by a supplier in Guidel, near Lorient. The point on which the compass rose rests is made of sapphire, a fundamental part of the compass's operation. This very hard gemstone prevents wear and deformation, ensuring long-term compass accuracy.
Pre-assembled compass
Pre-assembled compass
Filling
In the open air, the slightest movement causes the rose to move and makes the compass unreadable. It is necessary to fill the volume of the instrument with a liquid dense enough to reduce rotations. Another visual effect of the filling is that the diffraction magnifies the rose. It seems to occupy the entire volume while its diameter is only half that of the container. The compass is now easier to read.
Filling the compasses (Note the difference in perception of the size of the rose between the empty compass and the one being filled.)
Expansion test
During its life, the compass will have to undergo significant temperature changes. To ensure that the pressure inside the compass remains constant and thus keeps the compass movements unchanged, a membrane allows the liquid to expand in the event of high heat. To check that they are working properly, the compasses are passed through ovens.
The metal shims in the white tank allow the distance between the half spheres of the compass to be adjusted for the proper functioning of the expansion diaphragm
Interior equipment, furniture, material and electrical equipment used in the cabins: Vimar for its
Once the controls have been carried out, the compasses are equipped with various accessories, such as electric lighting for night use.
Installation of accessories
Manufacture of lids
Another curiosity is that Plastimo manufactures internally the protective covers for its compasses. The manual process used produces a flexible but not very brittle plastic to resist repeated handling. A heated mould is immersed in a liquid plastic bath, which adheres to the metal. It is then baked in the oven for baking. The operator's know-how and soaking time ensure that the desired thickness and flexibility of the part is achieved. The process is also used for air bags or Plastimo spreader protections.
Moulds for plastic parts
Compass covers
Air bags
The compasses are finally packaged in a box adapted for boaters or shipyards as original equipment.
