Marine diesels create very high noise levels – often well over 100 decibels. Engines are always located close to the boat user, generally in engine spaces made from GRP, timber, or steel. Noise insulation changes all this. It adds a soft facing to hard bulkheads to absorb noise and stop it bouncing around and growing. It features a clever multi-layer construction to make a thin material more effective than simple insulations many times thicker.
• The absorption layer
A thick layer of fire zero rated foam which soaks up noise and stops it bouncing around the engine space.
• The transmission layer
A high density barrier provides the highest possible mass and gives the best noise reduction. The damping layer weighs 5kgs per square meter – more than the lead sheet used in older materials.
• The isolation layer
This thin layer of foam has a crucial function: It acts like the gap in double glazing and stops the noise which hits the transmission layer being carried through to the bulkhead – just like the gap in double glazing.
The multi-layer construction used in Halyard® materials offers the best possible acoustic result in a thicknesses which can be accommodated in the tightest engine space, beating simpler materials many times as thick.
An immensely tough fibreglass cloth with a sealed metallised skin so it cannot absorb oil. It won’t tear or fray. It looks heavy duty, and it is fire zero rated. Maritex is simply the best facing in the Halyard® range. Maritex is fire zero rated to BS 476 parts 6 and 7.
A tough off-white glass cloth, sealed against oil. The cloth is extremely tough and will not tear. The sealant will burn off in a fire. The material meets the ISO 9094 fire requirements of the EU Recreational Craft Directive.
• Re-inforced Silver Polyester
This facing meets the requirements of the Recreational Craft Directive. It provides a seal to keep oil out. You can pierce it, but it has a reinforcing layer behind it. It will burn, but once laminated in place it meets the ISO 9094 fire requirements of the EU Recreational Craft Directive. In a fire the facing will
burn, but not the foam behind it.
HOW TO CHOOSE THE PROPER THICKNESS
• 45mm (1.75").
This unique double damper material was invented by Halyard® and is designed to give the best possible result for the minimum thickness and weight. It is used where big turbo-charged engines are involved, or for vessels where noise is a particular problem. Supplied with 2 sheets 1000 mm x 600 mm (39” x 24”) per box
• 2mm (1.25").
The standard thickness used throughout the industry. Today’s fire zero rated foams have increased the weight and made this material even more effective. 32 mm is the choice for any installation where the builder wants an excellent result at a sensible cost. Remember, you can always double layer it in critical areas. Supplied with 4 sheets 1000 mm x 600 mm (39” x 24”) per box
• 12mm (0.5").
The budget material when thickness or cost are crucial. Although it is only 12mm or half an inch thick, this material is highly effective and will reduce noise by 50% if used properly. You can also double layer it in places. Supplied with 4 sheets 1000 mm x 600 mm (39” x 24”) per box
|12 MM (1/2") MATERIALS
These material offers around 12dB reduction at 1000Hz and above, but its efficiency reduces with the heavier noises of lower frequencies. The overall reduction will give excellent results with smaller, lighter engines.
|32MM (1.25") MATERIALS
The 32 mm materials offer a startling 15dB reduction at 1000Hz. Noise doubles every three decibels, so this is nearly three times as good as the 12mm. It also holds a good performance at lower frequencies, making it excellent with larger engines.
|45MM (1.75") MATERIALS
These materials offer more noise reduction than other. They are suggested when noise is a serious problem.