sound deadening

[jim rosenthal]

Although I've located a sound shield for my NL generator set at a terrific price, it's not clear that there's going to be room for it. The exhaust output from the turbocharger outlet on the port engine comes far enough into the middle of the engine room that I don't think the sound shield will be able to fit in there.

I would like to hear of any experience any forum members have had with updating the sound insulation in their engine rooms. Hatteras Yachts of this vintage had sound deadening installed as part of the hatches and the salon deck (this is a 1971 36 convertible) but the material has aged, etc. I don't mind the engine noise while underway, but I would like to be able to run the generator at anchor and have less noise. It isn't earsplitting, but it's noticeable....

 

[saltshaker]

Although I've located a sound shield for my NL generator set at a terrific price, it's not clear that there's going to be room for it. The exhaust output from the turbocharger outlet on the port engine comes far enough into the middle of the engine room that I don't think the sound shield will be able to fit in there.

I would like to hear of any experience any forum members have had with updating the sound insulation in their engine rooms. Hatteras Yachts of this vintage had sound deadening installed as part of the hatches and the salon deck (this is a 1971 36 convertible) but the material has aged, etc. I don't mind the engine noise while underway, but I would like to be able to run the generator at anchor and have less noise. It isn't earsplitting, but it's noticeable....

When I repowered my '74 46C I replaced all the OEM stuff with SoundDown. I think it was 3" but can't remember. The stuff I used had a vinyl layer sandwiched between foam. The difference is incredible. The key to the whole job is making sure there are no gaps or leaks. If you have carpet, they sell a vinyl underlayment that works well. I was going to use it when I put the new carpet in after the job was done. We sea trialed with bare floors and I was so satisfied with the results of the ER sound proofing that I never used the underlayment. The carpet knocked down the high pitch turbo whine but other than that it was about the same. On mine the old stuff came out very easily. All the screws came right out and the panels were not glued up so they popped right out. Don't bother with their fasteners. I bought stainless screws and fender washers instead. One of the best upgrades I made to the boat.

 

[jim rosenthal]

Thank you. If there's no way to get a sound shield around the generator set, I may go with that alternative.

 

[the kuz]

Jim, another easy thing you can do to quite things down is to seal up any spaces around your salon floor hatches. Try closed cell foam weather stripping insulation (the kind that comes in rolls and is sticky on one side) applied to all mating surfaces where your salon/engine room hatches sit. My wood frames sat directly on the aluminum support "T" beams and let both sound and dirt/haze come through. I used 3/8 thick x 3/4 wide foam attached to the aluminum so the hatch frames would sit on the foam. Also ran a strip down the side of one hatch where two hatch panels are used/mated in the same hole. After a while it compresses down pretty thin, so eventually I will replace with 1/2 thick. It did lower sound in salon quite a bit from both engines and gen. We too have the old OEM stufff on the bottom of the hatches, but the edges are just painted wood.

Even if you use some type of sound absorbing material, noise will still leak around the hatches if you don't seal them. It is a very easy job and does not take long or cost much. Might be something better than what I used, since it has to be re-done every few years once the foam compresses.

Best Regards, Bob K

 

[administrator]

Jim,

We purchased a substantial amount of Soundown noise dampening insulation from Hatteras a while back. I could let you have some for less than cost. Look up part numbers 81454 and 81455 in our catalog. I think the rolls are 54" wide and there's about 400 sf per roll. Here's their web site... http://www.soundown.com/index_Marine.htm

 

[jim rosenthal]

Will do, and thanks. I will be in touch. With her laid up for the winter, this would be the time to attempt this.

 

[jim rosenthal]

We looked at the generator set and the information that comes with the sound enclosure, and it appears a very difficult fit. Even if we could beat it into there, service access and the required free space around the enclosure and getting all the hoses and cables in and out of the box are still a problem. I'm going to look at the sound insulation Doug has and see if I can determine how that would work. It would also have the advantage of making the boat more quiet while running, not just with the genset on at anchor.

Ironically, this all began with my idea of trying to build a sound box. Ultimately I may end up at least putting some absorbent baffles around the set. But a full sound box, where it is, seems to be too difficult- and there really isn't anywhere else to put the set, even with a lot of surgery in the engine room.