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    Generator sound shield-gctid343757

    The admiral has decreed that "we" need a sound shield on the generator to make it quiet enough to sleep with it on (we sleep in the aft, right by the generator). I started a conversation over on the Boat US forums about it and got some ideas, but figured I should ask here since I think most 3055s came with the same generator. I don't know if the sound shield was a factory option, or never included. If it was an option there might be an opportunity to call junk yards and see if they have a dead 3055 with one. It's $2k-ish new, which seems insane for a box.

    The generator is a Westerbeke 4.5 BCGTC, which seems to be standard on all 3055s of that timeframe.


    Here is the Boat US conversation if anyone wants to read it:

    Carlos, the only thing I can add is that I have crawled around a number of trawlers that had sound shields made of commercial ceiling tiles. They look like a 3/4" thick fiber tile with perforations on one side. I imagine that they're fire resistant. You could glue them to a surface. Many trawlers had them support by a frame. These tiles are fairly common in most home improvement stores. If it didn't work, you wouldn't be out very much.

    Another product looks like 2" thick black foam with an egg carton pattern on one side. The material is fire proof. This can cost more, but may work better. Typically, you would glue this material to a thin piece of plywood, plastic or sheet metal.

    Lastly, is a product found in most auto parts stores. It is used in cars for sound dampening. It's a roll up fiberglass mat covered in heavy foil. Typically, this is glued to the inside of an engine compartment to quiet the motor. If you cut this material to fit, you need to bind the edges, or it can split in half.

    Being the paranoid type, I would recommend dual CO detectors.



      There's also the product used in marine engine bays (Bayliners and others). It comes in several thincknesses and is made of 4 layers: Foil (faces engine), foam core, heavy vinyl (this is the most important factor in sound proofing), and foam again. I've seen in for sale in marine shops, fairly expensive though but you can cut it to suite.



        I also suggest looking at other potential noise issues besides shielding. Another aspect of sound transmission is how the unit is secured to your boat. Frequently the mounts are the issue. The mounts/rubber can get poor or hard resulting in greater sound transmission/amplification. Better aftermarket mounts are also available.


        Pugetsoundog (woof)


          Are you sure about the $2000 price tag on this? I thought I paid major $ because everything in Canada is twice the price compared to the US. Bought mine locally for $750 although this was almost 5 years ago. Take a look at my album in my signature. Can't see very much but it is there. Same genny as you. They are very well made and access to anything is literally a snap.

          On another note. Another source of noise ids the exhaust. I call it the Wind Bag burble because it sounds like a sailboat under power. I installed a gensep which basically eliminates all noise at the exhaust level. See here.

          EDIT: OOpps my bad, you have a Westerbeke and mine is a Kohler. :surr
          Cheers, Hans
          2007 Carver 41 CMY
          Twin Volvo D6-370
          Montreal, Canada
          Midnight Sun I Photos


            Craig, some good ideas there. I do have CO detection in the cabin and in the cockpit both.

            On another note. Another source of noise ids the exhaust. I call it the Wind Bag burble because it sounds like a sailboat under power.
            This is audible in the cockpit, but not at all in the cabin.


              Is there anything surrounding it now?

              Have you seen Dynamat

              I know they use it in cars all the time. It's usually for better quality sound though.



                Nothing there now. I'm intimately familiar with Dynamat and have used it a lot, but I'd first have to build an enclosure. That sounds simple, but it's not, the factory enclosure has very deliberate engineering around airflow and then killing noise that open holes would allow to get out.


                  The admiral has decreed that "we" need a sound shield on the generator to make it quiet enough to sleep with it on (we sleep in the aft, right by the generator).

                  It's $2k-ish new, which seems insane for a box.

                  Carlos, I'm certainly no expert on this, so I'll ask these as questions:

                  Do you think that the generator isolation (i.e., engine mounts) is a great part of the sound transfer into the hull and other areas?

                  IOW, just how much sound is actually being produced by the generator engine, apposed to how much sound is a result of engine vibration being transferred through the hull's structure?

                  I'd think that asking this generator to quiet down while you are sleeping adjacent to it, is asking quite a bit.

                  Rick E. (aka RicardoMarine) Gresham, Oregon
                  2850 Bounty Sedan Flybridge model
                  Twin 280 HP 5.7's w/ Closed Cooling
                  Volvo Penta DuoProp Drives
                  Kohler 4 CZ Gen Set

                  Please, no PMs. Ask your questions on forum.


                    Maybe obvious, but does your bulkhead have the sound-deading foil pad on it? Not sure for your year, but mine does.
                    Jeff & Tara (And Hobie too)
                    Lake Havasu City, AZ
                    Current: 2022 Sun Tracker Sport Fish 22 XP3 w/ Mercury 200
                    2000 Bayliner 3388 Cummins 4bta 250s (SOLD 2020)
                    2000 Bayliner 2858 MCM 7.4 MPI B3 (SOLD 2018)
                    2007 Bayliner 305 MCM twin 350 Mag B3s (SOLD 2012)
                    2008 Bayliner 289 MCM 350 Mag Sea Core B3 (SOLD 2009)
                    And 13 others...
                    In memory of Shadow (7-2-10,) and Ginger (5-11-21.)
                    Best boat dogs ever! Rest in peace girls...


                      Yes, but it's pretty light foam and I don't think it does a whole lot for sound deadening.


                        not designed for marine use, but there is a product we use in shcools to quiet down the music rooms. Its called tectum panels. looks like a bunch of string compressed together to form a panel. I buy it in 2ft. X 8 ft sheets - 1 inch thick. its rigid and fireproof. Can be cut to fit and installed against existing bulkheads. costs about $5. sq. ft.


                          The ultimate for sound deadening is lead. All of the truly effective products on the market contain it in some quantity or another. The sound shields I've seen weren't that technically intricate, just boxes with room for everything inside and shielding to slow the transfer of sound waves. I'm sure if you wanted to construct your own, you could find someone who would let you look at theirs.