Stainless Exhaust or Glass

[ub1]

I have a stainlesss wet exhaust on a yanmar 4jh2e and have to replace it. Does anyone know if a fiberglass or plastic muffler could be used instead of stainless? Also a good source for one.

[SkiprJohn]

If water is injected into your exhaust system then fiberglass is ok. I have some 1 foot pieces of 1 1/2" fiberglass tubing if you are interested in purchase. You might need thinner though. I epoxied together shaped sections to make the necessary bends I needed and it turned out really good. That was suggested by another member and my local boatbuilder and it was a great suggestion.
Kind regards,

[r.furborough]

fiberglass or plastic is OK if you have a minimum of 12" of marine rated rubber exhaust hose after the water injector. The gives sufficient distance to allow the water to cool the exhaust gases before they hit the waterlock/muffler.

[SkiprJohn]

Here's a photo of the compounded curve elbow I built for my engine. You can see the tubing used.

[mikereed100]

Originally Posted by SkiprJohn

Here's a photo of the compounded curve elbow I built for my engine. You can see the tubing used.

John,

You just saved me a ton of work! I have been scratchng my head trying to come up with a way to laminate up some fiberglass elbows for my exhaust and fuel fill hoses. It never ocurred to me to just glue up some straight stock. Just put in an order to McMaster and Carr and it was cheaper than laminating my own!

Mike

[SkiprJohn]

Aloha Mike,
I started with straight stock and just cut the angles. Then hot glued them together one angle at a time to the right shape in order to epoxy using 10oz glass strips. I did one section at a time because I wanted to reach in with a dremel to smooth the interior before finishing. Because my epoxy didn't dry very quickly I put the project in a cardboard box and left a lightbulb burning over a couple hours. Very humid here when I was doing the project.
Good luck on your project!
kind regards,

[SkiprJohn]

Aloha r.furborough,
I'm not certain the combustion temperature of the fiberglass tube but I would assume that rubber hose would melt or burn before it does.
Do you know for certain which would go first?
regards,

[JayH]

Centek makes fiberglass mufflers and exhaust fittings in various configurations.

Centek Industries - Products

[Nauticatarcher]

Another way if your Stainless exhaust Box is just leaking is to encase whole thing in Fibreglass using epoxy resin so it will stick to metal, we did this and gave us another 4 yrs and it was still going fine when we sold boat, basically your old box is just an internal mould that stays in place, just make sure internal tubes are still OK