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Engine Compartment Insulation - Recommendation?

Discussion in 'Engines and Propulsion' started by jviss, Jun 13, 2018. Add this thread to a FAQ

  1. jviss

    jviss

    Joined Feb 5, 2004
    2,375 posts, 195 likes
    Tartan 3800
    US Westport, MA
    The engine compartment insulation on my Tartan 3800 is coming apart. It's self-stick foam with a foil facing. In some places the foil has peeled and is falling off. Elsewhere entire pieces of insulation have fallen off.

    What's the best insulating material for this application, and where do you get it?

    Thanks,

    jv
     


  2. JamesG161

    JamesG161

    Joined Feb 14, 2014
    2,639 posts, 681 likes
    Hunter 430
    US Waveland, MS


  3. JamesG161

    JamesG161

    Joined Feb 14, 2014
    2,639 posts, 681 likes
    Hunter 430
    US Waveland, MS
  4. All U Get

    All U Get

    Joined Oct 2, 2008
    2,500 posts, 243 likes
    Pearson/ 530
    US Strafford, NH
    I used the stuff with lead in the middle, got it from Defender.
     


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  5. Rich Stidger

    Rich Stidger

    Joined Feb 10, 2004
    2,730 posts, 205 likes
    Hunter 40.5
    US 1997 h40.5 Bristol, RI
    There are a variety of products offered from a "paint" to special sound absorbing foam. In my generator compartment I used Soundown Acoustic Lead Barrier. I can't remember if I used the 1 or 2 lb lead sandwich material. The lead in-between the foam absorbs the vibration and sound and greatly decreases the transmission of sound to walls. It is foil faced to be resistant to oil and fuel. It is relatively hard to apply since it is quite stiff. But it has worked well for me. It is available from Amazon and from Jamestown Distributors. Be sure to also check on this SBO site.
     


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  6. jviss

    jviss

    Joined Feb 5, 2004
    2,375 posts, 195 likes
    Tartan 3800
    US Westport, MA
    Thanks AUG and Rich. The Soundown site is at first a bit clunky, but has a lot of good, tutorial information. There's a handbook, and detailed suggestions for soundproofing all kinds of vessels, including sailboats.
    Good reading!

    Only thing is, this is a difficult and time consuming job, to replace the sound and heat insulation material; and it seems it might get expensive.

    Other than the self-stick stuff, which is failing on mine, what's your method of attaching this stuff?
     


  7. jviss

    jviss

    Joined Feb 5, 2004
    2,375 posts, 195 likes
    Tartan 3800
    US Westport, MA
    Wow, reading the Soundown documents, doing this properly is not trivial. One important point in their list of Do's and Don'ts at the end of the installation manual: "Don't rely on adhesives Alone for permanent attachment."
    They show either pin fasteners with speed nuts, or screws with fender washers.

    I have no idea yet how I will insulate the inside of the one-piece, molded fiberglass companionway stairs, which were never insulated to start.
     


  8. Rich Stidger

    Rich Stidger

    Joined Feb 10, 2004
    2,730 posts, 205 likes
    Hunter 40.5
    US 1997 h40.5 Bristol, RI
    I used their pin fasteners. They stick to the wall or mounting surface and then the insulation is impaled on it. On the sides of my generator compartment I needed to slide the insulation parallel to the wall and between the wall and the generator. For that application, I covered both sides of the insulation lead sandwich with foil and just slid it into place. Not perfect, but there was no way I was going to pull out a 375# genset just to sound insulate. Even with my imperfect installation, the noise reduction was great. My genset can still be heard running, but a conversation in normal volume can be held next to it.
    For your companionway stairs I would use both spray adhesive (3M makes a good one) and the pins. Carefully measure your clearance so you buy the maximum thickness that will fit.
     


  9. jviss

    jviss

    Joined Feb 5, 2004
    2,375 posts, 195 likes
    Tartan 3800
    US Westport, MA
    Thanks Rich. How did you fasten the pin fasteners to the mounting surface?
     


  10. Rich Stidger

    Rich Stidger

    Joined Feb 10, 2004
    2,730 posts, 205 likes
    Hunter 40.5
    US 1997 h40.5 Bristol, RI
    I forget. Maybe epoxy. Sounddown has the instructions.
     


  11. FastOlson

    FastOlson

    Joined Apr 8, 2010
    930 posts, 81 likes
    Ericson Yachts Olson 34
    US Portland OR
    I just put new foil-foam (1") throughout my engine compartment. The original stuff had crumbled and I had to scrape off the remnants about 15 years ago. Biggest reason for the original failure was that the factory had never sealed the edges where heat and fumes had attacked the exposed foam.
    Now it's all new and all edges are sealed with silvery mylar tape ($$). I also used screws and fender washers at all corners upon the advice of a boat builder friend.

    It is a hard job on most boats due to poor access --- I was able to do it relatively fast because we had removed the old engine in order to install a new Betamarine. I did scrape down the walls and clean 'em with solvent to get most of the original adhesive off.
    I used spray adhesive for the new application. It all seems well-adhered, but we will only know for sure in another decade. :)
    As for the double-layer foam with the lead in the middle... I have heard that it helps. The industrial supply place where I bought this product did not believe that it helped very much, even tho they sell it for more $. Plus, it is harder to apply. Maybe I made the correct decision; or maybe not. Anyhow, it's done.
    (BTW, the new engine is so much quieter that the foam layer is a little less important than it once was !)
     


  12. Captain Larry-DH

    Captain Larry-DH

    Joined Jun 14, 2010
    325 posts, 113 likes
    Quorning Dragonfly 1200
    US home
    I just completed a Soundown installation. I used two 3/8” stainless sheet metal screws for each pin base plate, and a dab of 5200 as adhesive. The drill bit was taped to limit depth of the screw pilot holes.

    PS -this is a big job and I had the boatyard pull my engine to allow better access. It was still challenging, best if you can find someone small and flexible. I did the removal of the old crumbling material and it was very strenuous work. I hired out the installation portion of the job. IMHO- this is one job where my checkbook was the best tool.
    (While the engine was out I had it cleaned and painted, and other proactive maintenance was performed including replacing exhaust and cooling system parts that are normally subject to raw water corrosion).
     


    Last edited: Jun 14, 2018
  13. All U Get

    All U Get

    Joined Oct 2, 2008
    2,500 posts, 243 likes
    Pearson/ 530
    US Strafford, NH
    After three years of many hours motoring the East coast, ours started to sag from the ceiling part so I used seizing wire to hold it up.
     


  14. SEMPERAVANTI41

    SEMPERAVANTI41

    Joined Jun 15, 2012
    375 posts, 22 likes
    Hunter 50 AC
    US Greenport, NY
    FYI apps are available for smart phones that measure db's. After I used the Soundown lead foam to further insulate my Fischer Panda generator, I measured a 3 db sound decrease. Nice to know that the expense accomplished something for real.
     


  15. LeslieTroyer

    LeslieTroyer

    Joined May 20, 2016
    1,523 posts, 475 likes
    Catalina 36 MK1
    US Everett, WA
    :worthless:Where are all the photos of the finished work??
     


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  16. JamesG161

    JamesG161

    Joined Feb 14, 2014
    2,639 posts, 681 likes
    Hunter 430
    US Waveland, MS
    I guess I am confused on the use of Lead, unless it is a nuclear powered engine.:confused:

    For my engine and genset compartments.
    1) Sound dampening----YES
    2) Engine heat reduction to Cabin interior--NO .. unless you have a forced exterior Air Supply to the engine compartment.
    3) Reflective silver foil that returns Radiant Heat back to the heat source [engine]---NO [see item #2] perhaps you are hoping that the Sea Water cooling removes more heat? My thermostats run a constant temperature.

    I replace all my genset and engine sound damping with a better sound and heat retardant at a cheaper price in my post #2 above.;)
    Jim...

    PS: I even built a sound enclosure box around my 16k AC unit with Duct Board. One end open.:)

    PSS: Please note that Duct Board has a built in reflective exterior.
     


    Last edited: Jun 14, 2018
  17. SEMPERAVANTI41

    SEMPERAVANTI41

    Joined Jun 15, 2012
    375 posts, 22 likes
    Hunter 50 AC
    US Greenport, NY
    From the description on Defender's website:

    "Composite of acoustic grade polyester urethane foam, with high density leaded vinyl barrier " .

    Lead is an excellent sound control material. I believe it was even used by Fisher Panda in some generator sound shields.
     


  18. jviss

    jviss

    Joined Feb 5, 2004
    2,375 posts, 195 likes
    Tartan 3800
    US Westport, MA
    There are three active elements in good sound absorption materials: absorbing, mass layer, and dampening. Lead sheet is an excellent mass layer, as it is "dead," i.e., non-resonating. (According to my recent education on this.) The reflective material is to protect the sound material from excess heat.
     


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  19. JamesG161

    JamesG161

    Joined Feb 14, 2014
    2,639 posts, 681 likes
    Hunter 430
    US Waveland, MS
    :plus:
    I am curious the dB reduction per pound of Lead versus the foam board.
    But...
    I do know that foam board can be disposed of in a normal garbage dump, where Lead cannot.
    Jim...
     


  20. Captain Larry-DH

    Captain Larry-DH

    Joined Jun 14, 2010
    325 posts, 113 likes
    Quorning Dragonfly 1200
    US home
    OK - Here's what it looked like after I removed the old.

    IMG_0296.jpg

    Here's the finished result:
    IMG_0334.jpg

    BTW I also used the Soundown spray adhesive that came with the kit. So it was adhesive AND the Soundown pin system. (That pin system is really great.)
     


    LeslieTroyer likes this.

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