Fiberglass mufflers

Discussion in 'Modifications/Customizations' started by DougLas, Apr 12, 2014.

  1. DougLas

    DougLas Member PLATINUM Sponsor

    476
    Dec 13, 2008
    Lake Erie
    39 Express
    454
    Has anyone repaired the fiberglass mufflers on the gas engine 39 Express's. I have mine off and I'm thinking of using West Epoxy System to repair them. Unless there's a better way to fix them.
     
  2. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    There might be a better way but......,
    I used WestSystem thickened epoxy with fiberglass mat and cloth to fix mine years ago and it's held up perfectly.
    (By the way it's possible to crack the muffler, if your timing is wayyy out and you get a good backfire.....don't ask).
    [​IMG]
     
  3. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Also, your local home center has rubber plugs and caps that you can make a up a simple system to pressurize the can to ensure its leak proof before reinstalling.

    I pumped mine up to 20psi and sprayed it with soapy water looking for leaks.
    Then, left it over night and it still held the pressure in the morning.

    Good luck with it,
     
    Last edited: Apr 12, 2014
  4. Capt. Rusty Higgins

    Capt. Rusty Higgins Active Member PLATINUM Sponsor

    778
    Nov 6, 2006
    Cape Canaveral, Florida
    Sea Ray 18CC Laguna
    if it burns, it turns
    ask for fire-retardant epoxy or resin when repairing mufflers please.

    R
     
  5. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Edit for my earlier post!
    (I can't seem to get back in to add the edit)

    Add "WestSystem 421 Fire Retardant" to the mix for the epoxy to be used in this application.

    :)
     
    Last edited: Apr 12, 2014
  6. Paul_P

    Paul_P New Member

    39
    Jul 7, 2013
    Catawba Island - Cleveland,Oh
    1992_330_EC
    Twin_7.4L , Hurth Trans.
    I have a muffler that is leaking water and i assume exhaust fumes and requires attention. My intention was to buy a new one , but if it can be fixed i am all for that. Do these mufflers have baffles/ports inside which crack and leak? OR Is the outside shell the only part which leaks water/fumes?. I guess the ultimate question is once you fix the outside crack - is that all there is to it?.

    Thanks - Paul
     
  7. DougLas

    DougLas Member PLATINUM Sponsor

    476
    Dec 13, 2008
    Lake Erie
    39 Express
    454
    Thanks for the info i'll get the fire retardant.
     
  8. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Not sure if yours are the same as my water lift mufflers....but, will be something similar.
    Its very easy to mix up some WestSystem epoxy thickened with 421 fire retardant and spread its on like peanut butter. You can add bandaids strips of fiberglass if necessary.
    Prep the muffler by sanding off the paint and wiping with acetone.

    :)
     
  9. Paul_P

    Paul_P New Member

    39
    Jul 7, 2013
    Catawba Island - Cleveland,Oh
    1992_330_EC
    Twin_7.4L , Hurth Trans.
    Air O'Nautical. Thank you for the directions on how to repair a muffler. I will be looking into repairing mine over the next two weeks. I was always concerned that there may be something cracked internally that may need attention - from your instructions this does not seem to be a concern.

    Paul
     
  10. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Why do you think it's cracked inside?
    Its inexpensive to repair vs replacing.
    So, I say give it a try....
     
  11. Paul_P

    Paul_P New Member

    39
    Jul 7, 2013
    Catawba Island - Cleveland,Oh
    1992_330_EC
    Twin_7.4L , Hurth Trans.
    Mark,

    I think i may have worded my original question incorrectly. I was trying to ask - Is there anything inside the muffler which could be cracked that i should be concerned with?. I do not know how a muffler is constructed - nor do i really know how it functions. To me if something is cracked on the outside it means something could also be cracked on the inside.

    I will follow your directions on repairing the muffler and go forward with this. I greatly appreciate everybody's advice - i think i just saved somewhere between $500 and $750! - can't beat that.

    Thank you, Paul
     
  12. DougLas

    DougLas Member PLATINUM Sponsor

    476
    Dec 13, 2008
    Lake Erie
    39 Express
    454
    I talked with West System about the mufflers. The one on the 39 Express is fiberglass with plastic cover on top and bottom. They said the 105 epoxy will work on both surfaces. The plastic surface has to be flame treated to insure good adhesion. They said to use a propane torch on the plastic parts to open them up so the epoxy will stick better. I assume this gets rid of the silicone in the plastic.

     
  13. John Leyden

    John Leyden Member GOLD Sponsor

    90
    Jul 7, 2017
    New Port Harbor California on my Mooring
    Sea Ray 00' 340DA (Anna Mei II)
    Was 310 HP MPI --> Twin full 454 Mer-Cruiser 400 hp "Gas Aspirated" Less to worry! Works for me!
    5/17/19 Was told to use "Polyester Resin --- Reichold Dion ISO6631T Resin --- Can order it from: WWW.mertons.com
     

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