Fiberglass mufflers

DougLas

Well-Known Member
Dec 13, 2008
874
Lake Erie
Boat Info
39 Express
Engines
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.
 
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).
611DD2FE-E93C-4516-BA0F-CE1578785F24-19978-0000366C0EC60B8B_zps5062bee2.jpg
 
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,
 
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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.

:)
 
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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
 
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

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.

:)
 
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
 
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
Why do you think it's cracked inside?
Its inexpensive to repair vs replacing.
So, I say give it a try....
 
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
 
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.

 
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.

:)
5/17/19 Was told to use "Polyester Resin --- Reichold Dion ISO6631T Resin --- Can order it from: WWW.mertons.com
 

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