Boat Forum / Building / September 2005

Hi
New to here, saw you are looking for a way to reduce noise from your engine
room. There is a system sold that is quite effective but can be a bit high
in price, Sound Down (not the floor under lay) a marine system sold out of
Maine or mass. The system has two layers of high density foam with a thin
sheet of lead laminated between them. The foam laminate is attached to
deckheads, bulkheads and hull surfaces in the engine room. It is then
covered with a perforated aluminum diffuser plate. The purpose of the
diffuser plate is to break up the sound waves before they enter the foam to
be absorbed.
One of the things I think you are looking for is a cost effective way to do
this task, sound down systems would most likely not be the product for you.
If you want to MacGyver a system just make some substitutions and you should
have a good level of success. Any acoustic dampener such as the panels used
in out-door theaters (I believe they are water resistant) attached to the
deckheads or bulkheads covered with a 1/16" aluminum sheet would do the
trick. Space the aluminum sheet 1/8" away from the panel to allow the sound
waves the area the need to disperse. The aluminum plates should have 1/8'
holes drilled  on one inch centers or less. The tighter the hole pattern the
better the system will work.
If you are using the system in an area where you have need of a finished
living area surface you can strap over the aluminum and attach your desired
finish surface to the strapping. This type of system can be installed in
just the machinery areas or through out the vessel depending on your need.

Doug