Sound proofing foam panels

[osprey877]

I am looking at soundproofing my engine compartment with 24” foam soundproofing panels. They are egg carton patterned and about 1” thick and seem to be intended for use in sound studios and speaker boxes. My wife is worried they could be a fire hazard. The specs do not mention the fire rating, but I have seen them used on other boats. Does anybody have any experience with these and/or know if they are a fire hazard??

[mako]

We installed those in our sound studios and foley rooms, but what they do is temper reflected sound waves - in other words they knock down echos. But I think what you are looking for is sound absorption and insulation against transmission.

So you can look into mass-loaded vinyl sheets or the lead-foam-foil sheets. Much heavier and better at keeping the noisemaker noises where they belong.

But don't forget that sound transmits anywhere there is physical contact between hard surfaces, and where there are gaps. Look at the whole picture if you want effective performance. You need dense rubber gaskets on hatches and doors, watch for pieces of fiberglass inside and outside the engine room which touch each other, install some rubber pads or feet on objects, air ventilation shafts can be lined on the inside with sound-attenuating materials as well, etc.

[osprey877]

Originally Posted by makobuilders

We installed those in our sound studios and foley rooms, but what they do is temper reflected sound waves - in other words they knock down echos. But I think what you are looking for is sound absorption and insulation against transmission.

So you can look into mass-loaded vinyl sheets or the lead-foam-foil sheets. Much heavier and better at keeping the noisemaker noises where they belong.

But don't forget that sound transmits anywhere there is physical contact between hard surfaces, and where there are gaps. Look at the whole picture if you want effective performance. You need dense rubber gaskets on hatches and doors, watch for pieces of fiberglass inside and outside the engine room which touch each other, install some rubber pads or feet on objects, air ventilation shafts can be lined on the inside with sound-attenuating materials as well, etc.

Thanks. That’s good advice. I will see what’s available in barrier products.

[Wood]

Don't ignore fire rating either. Look up the "Station Nightclub" fire in Rhode Island in 2003 where that material was used as sound proofing. It is not appropriate for use in an engine room. Diesel or otherwise.