In part 3 of the Hummer H1 project we will deal with the bonnet.

Showcase Hummer H1 Part 3: Sound Insulation and Anti-drumming

Bonnet insulation

Vibration and resonance from the engine cause noise nuisance. In this third part you will see how we use the product Vibraflex Alu for the anti-drumming of the bonnet. In the meantime, this product has been replaced by STP Black Silver.

Let’s take the example of a gong (musical instrument) in order to explain how anti-drumming works. When a gong hangs freely you will hear a clear sound when you tap on it. When you hold the gong with your hands, on the contrary, you will hardly hear any sound when it is being tapped on. As for the anti-drumming of the bonnet, we try to reach a similar result. Apart from the anti-drumming effect, the material that is used additionally functions as an insulating layer. Apart from vibration, noise is also being blocked. By installing sound absorbing materials the engine noise can be further reduced.

Absorption material for the bonnet

After the anti-drumming of the bonnet a layer of sound absorbing material is required, reducing the amount of engine noise that can escape. Which product you select will depend on the temperature resistance of the absorption material:

  • Merfocell PU: Absorption foam provided with an oil, dirt, and moisture proof top layer. Resistant against temperatures up to +80 °C.
  • Acusticab: Aborption foam provided with an oil, dirt, and moisture proof top layer. Resistant against temperatures up to +80 °C.
  • Merfocell FC: Aborsption foam provided with a glass fiber cloth top layer. Resistant against temperatures up to +110 °C.

More information about vehicle insulatio

On our page with solutions regarding vehicle insulation you will find the most common problem areas. Additional tips pages about various types of vehicles you will find here:

Questions? Contact

Do you have questions concerning this topic? Please feel free to contact us, we will be happy to answer your question as soon as possible.