Sound Absorption in Pilothouse

I have reduced considerably the noise from my engine in various ways. My pilothouse ceiling is bare fiberglass (plywood core) and I would like to cover it with some kind of sound absorption material. There are no beams or stringers. What materials have you used and how effective was it? There is regular foam backed vinyl but it seems too thin to be effective. It would be good to have a surface that is somewhat resistant to damage and washable.

I would talk to this guy

Steve Moyer
Soundown
954 761-9188
www.soundown.com

I installed some of their lead sandwiched panels around my generator and it really helped.

We played around trying to reduce noise in our pilot house. What worked surprisingly well for us was just hanging a heavy fabric curtain at the top of the stairs going up into the pilot house from the saloon/galley area. I think it directly absorbed the sound before it got there. Our engine is pretty much centered under the saloon floor.

I lined Delfin with 1/4" additional cork before installing 2" coast guard Batts. It is a very good sound deadener in and of itself. www.jelinek.com

Some people use egg cartons... Seriously, stopping the sound before it leaves the engineroom works best. Lead sheeting on the inside of the engine room and foam on the outside.

What AK wants to do is reduce reverberation in the Pilot House, not reduce the transmission of engine noise from the engine room.

Covering it with just about anything soft will do the job, 1/2" of just about any soft foam covered in a thin vinyl (to allow noise transmission) will work, even 1/4" is good. The perforated vinyl headliners look very traditional and the perforations actually improve the absorption performance, but if anything wet ever gets though those holes and into the foam it will "bleed" if you touch it. That's why I prefer to give up some performance for a cleanable surface that's also a vapor barrier for the foam and will make it last longer.

It's actually more important to cover the hard surface than what you cover it with.

ak-guy said:

I have reduced considerably the noise from my engine in various ways. My pilothouse ceiling is bare fiberglass (plywood core) and I would like to cover it with some kind of sound absorption material. There are no beams or stringers. What materials have you used and how effective was it? There is regular foam backed vinyl but it seems too thin to be effective. It would be good to have a surface that is somewhat resistant to damage and washable.

Click to expand...

What I did was to ensure all mechanical pieces, engine mountings/engine/gearbox/shaft etc.are perfectly installed/aligned. If the air intake is attached directly to the engine then using a paper filter type air cleaner route it away from the engine and near to fresh air vent, don't forget to use reinforced hose that won't collapse from the suction, that will reduce engine intake roar by 30%.
I used a foam lead foam sandwich soundproofing with a wipe free surface called Quietlife to line the engine room and then I seated the floor bearers on a light foam.
That system worked perfectly well for me and hopefully it will for you.

I too can recommend that Steve Moyer at Soundown.com has a wealth of ideas and solutions

Jim

Std in dirt housing is 3/4 inch thick fiberglass with a sound damping facing.

It will require battens or T strips to hold it in place.

Some will create a "dentist office" look, but the same material is available in planks pattern that is more shippy.

Sound is energy , so it takes some material thickness to absorb it.

My dream is a noise cancelling gadget that could simply be powered to absorb the noise.

A portable one for resturants would be great too!

FF said:

Std in dirt housing is 3/4 inch thick fiberglass with a sound damping facing.

It will require battens or T strips to hold it in place.

Some will create a "dentist office" look, but the same material is available in planks pattern that is more shippy.

Sound is energy , so it takes some material thickness to absorb it.

My dream is a noise cancelling gadget that could simply be powered to absorb the noise.

A portable one for resturants would be great too!

Click to expand...

For Delfin's refit, sound deadening involved spraying the entire inside of the hull with sound deadening compound, then lining it with acoustical cork, then coast guard batts except in the ER where high density foam vinyl sandwich from Sounddown was used. In any case, she is very quiet.

Like you FF, I have wondered whether it would be possible to use similar technology to that in sound deadening head phones to generate specific wavelengths of sound to counter individual noises on a particular boat.

"Like you FF, I have wondered whether it would be possible to use similar technology to that in sound deadening head phones to generate specific wavelengths of sound to counter individual noises on a particular boat."

The tech is cheap and robust enough that it is built into mufflers on high tech cars .

To get rid of the din in an eatery , I would even carry a Boom Box sized unit if it would work!

Some turboprop airplanes also have a system like that

Take a look at the ceilings installed in Nordic Tugs.

My builder did a decent job in reducing engine noise in living spaces. Ceilings are soft, and the floor above the engine compartment is several inches thick.