The reason for bad sound insulation of the outboard engine's cover
The engine cover of most outboard engines is made from plastic or polyester. These type of engines are known for two weaknesses: lack of mass (light engine cover) and sound leakage.
There are also outboard engines that are placed in a well (kind of cover). This often results in reflections of the engine sound. The well amplifies the sound which makes the problem even more extensive.
Insulating the engine cover
First of all, you need to measure the amount of space between the engine and cover, allowing you to determine the thickness of the sound insulating material to be applied (always try to go for material that is as thick as possible in order to obtain the best result). Secondly, it's important to know the maximum temperature just under the engine cover, since this playes a big role in choosing the right material.
First, start by thoroughly cleaning the cover, which needs to be spotless and degreased. The temperatures under a small engine cover can get quite high. Self-adhesive products have to optimally perform, which is only possible on a really clean substrate.
When applying the insulation products (mentioned in this article), make sure to provide a seamless connection in order to prevent sound leaks as much as possible. You can also make templates from the parts that need to insulated, so that you are sure the insulation material will fit when mounting. Wrap the engine with insulation products as much as possible, but ensure that enough air can be supplied and exhausted.
- Merfocell FC: Sound absorbing plate provided with a glass gloth fiber top layer. Resistant against temperatures ranging from -40 °C tot +110 °C. Includes CE certification.
- Flamex FC: Sound absorbing plate provided with a glass gloth fiber top layer. Resistant against temperatures -40 °C tot +150 °C. Includes CE certification. Mounting only on flat, even surfaces.
- Aluglas 15S: Thermally insulating absorption plate. Suitable for rooms with limited space and high temperatures. Peak load: 458 ℃.
- Merfocell PU: Sound absorbing material to cover the well, not the engine cover! Make sure to seal the seams of this product very well, preventing it from absorbing moisture.
On our page Boats & Yachts you can find more solutions regarding how to insulate ships, both pleasure and commercial shipping.
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