Insulating For Sound

[Brian Degulis]

I'm wondering if anyone has done any insulating for sound on they're boats? I keep looking at the idea but with just about every square inch of bulkhead and overhead space covered with wires pipes equiptment etc. It just doesn't seem practical? Thoughts Ideas?

Brian

 

[DCMY #92]

We have a '65 41DCMY. I sound insulated the saloon from above. I put a layer of rebond carpet padding, a layer of lead impregnated vinyl and then the carpet. I covered the forward engine room bulkhead and underside of the steps to the galley with lead impregnated vinyl on the engine room side. I also have my gen-set in a sound enclosure. It helps allot at anchor with the gen-set running, but nothing can overcome the scream of the DDC 6V53s underway.

 

[yachtsmanbill]

At that point man, JUDISCIOUS use of spray foam and the shave it to look bad at best! Actually, when we did my Roamer, we used 2 inch styrofoam sheets and cut to fit after pulling everything possible outa the way. I still have the curse of little white balls! ( floating in bilge water) LOL. Thats a gigantic undertaking but well worth it! ws

 

[Fanfare]

My original engines were naturals, but new ones are turbos. That high pitched turbo whine comes right through. Used Soundown lead/foam carpet underlayment in saloon, but did not help much. I think the sound comes through the salon side walls (inside the wall) where the carpet doesn't reach. Next tried two layers of Soundown foam under each engine room hatch and out to hull. Big improvement, but still not ideal. Driving from flybridge is still the quietest, especially after adding mufflers under aft cabin twin berths.

Those engine rooms are just very noisy. Glad I have my ear protectors for my ER checks.

 

[Boatsb]

Jim the 2 ways to cut down noise is absorption and rejection (Isolation). I lined the hush box for my generator with 1" mineral wool and it worked great. I will be replacing the old mahogany panels with new ones and I will line the aft area of them with the same 1-2" mineral wool. It has great heat insulation characteristics ( wont burn and rated for 1200 degrees ) plus its reasonable inexpensive for a sound insulation. Just keep it dry. I think I paid about $17.00 of 10 sheets of 1" 20 x 36. Lining both sides will absorb the sound that would permeate through the walls and cut noise quite a bit. Also the frequency of the sound you want to affect may be important. Low frequencies have more energy and are harder to absorb.

 

[spartonboat1]

My original engines were naturals, but new ones are turbos. That high pitched turbo whine comes right through. Used Soundown lead/foam carpet underlayment in saloon, but did not help much. I think the sound comes through the salon side walls (inside the wall) where the carpet doesn't reach. Next tried two layers of Soundown foam under each engine room hatch and out to hull. Big improvement, but still not ideal. Driving from flybridge is still the quietest, especially after adding mufflers under aft cabin twin berths.

Those engine rooms are just very noisy. Glad I have my ear protectors for my ER checks.

The sound level of a pair of 6-71N's (no turbo's mind you) at full song without question requires ear protection, maybe plugs with muffs. At any rate, in a brain cross wire, their sound level reminds me of my old days in the 70's manufacturing disc brake rotors. The "roughers" (first cut machining of cast iron castings that really hogs off a lot of metal) would really scream...you could stand next to someone and yell as loud as you could and still not be heard well. They called me "muffs" cuz I always wore hearing protection, but I have pretty decent hearing at my 3 score age. I have worked for some senior managers in their mid-30's who have suffered hearing loss because of rock concerts attended, or in one case, from playing in a garage band. Unfortuneately, some guys lost theirs in war zones, while on artillary duty. You get one set of the cilia per side, so protect them.