can exhaust hose be repaired?

Hi Guys, hoping I can get some advice here. After moving some stuff in the engine room I noticed my starboard exhaust hose has what appears to be a rotten spot on the bottom where it sags about 4 feet from the riser. After this rotten spot the hose gently rises about a foot and heads off toward the back of the boat. The spot is only on the bottom about 8 inches square. It does not leak but I can peel off the thick black rubber coating exposing what appears to be cloth underneath.

Other than this spot, the hose looks ok. This is a massive hose, the black wire reinforced corrugated type, 6 inch diameter I believe, total length about 25ft from riser to back of boat. (Hoses are approx 20 yrs old)

The price of the hose would pale in comparison to the labour costs of tearing apart the boat to replace the whole hose.

Question: Can I just cut the existing hose downstream of the bad spot and splice in a new piece from here to the riser? Any ideas where one could find a suitable coupler of this size?

Appreciate any advice / guidance.

Can you just splice in a piece of fiberglass tube?

Even cheaper than hose. Or just use the glass tube as a splice...available at many marine places.

But it would be rare that just one section of hose would be bad unless it us an area exposed to high heat.

Yep, cut out bad section and splice in FG tube. Tube can be cut at an angle, then glassed back together to make angle pieces, if that makes your pipe run fit better.

Trident makes everything that you would need.


Trident Fiberglass Exhaust Tubing Connector

Thanks guys, I was hoping I wouldn't get beat up suggesting a repair.

I like the idea of cutting out the spot & replacing with a fiberglass tube but is this really wise given its so close to the riser? or does it matter? The other thing that concerns me is it would have to be a fairly long tube depending on how much I cut out.

Most of the hose is still wrapped in the clear plastic from when the boat was built. Interestingly, where it is wrapped the hose looks new, where the plastic is missing it looks like any 20 yr old rubber hose with the usual slight crazing or checking.

Psneeld, I quite agree the entire hose is suspect, it is very odd having a single bad spot. The only thing I can think of is possibly mechanical damage as the spot is near where a support hanger used to be in the distant past. Possibly also may have been rot from acidic exhaust gases because it is also a low spot but this shouldn't cause rot from the outside in.

Thanks for the link Larry. I'll check it out.

Ski, it's a straight section.

Checked out the JD site and they don't have 6" couplers in one brand and they are only 6" long in another so not long enough to bridge what I cut out. The tubing in 6" only comes in 10ft lengths.

Decision made, Looks like I'm stuck coupling in a new piece of hose. Same amount of work I guess.

Mine seems to be the same...the surveyor recommended it be changed 4 years and 7000 miles ago...not a drop or exhause leak yet.


I plan on replacing it this summer...mostly with glass tube and flex cuffs or angles where necessary...using as little hose as possible.


I can pull out drawers and cabnet bottoms and get to most of my hose...but yes...that's why I have delayed...plus I know an exhause tube. except right next to the elbow can almost be Cling wrap....it only had to get a little water and exhaust gas out the back of my boat. With a 120 Lehman on low....not much of a challenge and making a big deal of it show the ignorance of the whole marine system...some surveyors to yards to insurance companies.


Again...without seeing what field repairs are done on commercial vessels that last long after the voyage...I really wonder where some get their perspective/experience.


I have run the exhausts of a 454 for over a week under arduous condition just wrapping them with layer after layer of duct tape as it would get burned through till proper repairs could be done....Big Deal?....not even close.


I don't suggest you use duct tape or ignore it...and an exhaust leak in the spaces behind clothes lockers could be a mess....but just do it at your leisure using materials and methods you wish to work with....but take a deep breath as it certainly is no big deal.

Capt Kangeroo said:

Checked out the JD site and they don't have 6" couplers in one brand and they are only 6" long in another so not long enough to bridge what I cut out. The tubing in 6" only comes in 10ft lengths.

Decision made, Looks like I'm stuck coupling in a new piece of hose. Same amount of work I guess.

Click to expand...

you can also use metal tubing such as stainless or aluminum....the aluminum does have a much shorter life though...maybe 5-10 years depending on wall thickness and salinity of your cooling water.

someone on TF ...maybe one of our down under friends...had some custom tubing made up locally and it wasn't as bad as many thought costwise.

Go fiberglass. Metalic of any alloy is iffy due to corrosive stuff in exh.

And yes, many hoses are flunked by surveyors when they are still serviceable. But flaps peeling off, probably time to do something.

Also, don't forget to plug tailpipe when opening up exhaust. Don't sink the boat!!

Try here

Exhaust Elbows 6 | Marine Exhaust Systems

I replaced my entire SS exhaust system with fiberglass pipes and silicon joiners about 2-3 months ago. Only components left unchanged were the (FG) mufflers. Initially I had problems with the FB pipe splitting along the seem at the points the hose clamps tightened (and I don;t think I was being over-strong with the tightneing for what its worth). The glasser I used re-did them with carbon fibre around the ends (where the clamps go) and I have had no problems since.

I feel your pain, I once had to replace 11' of 6" hose, that is really tough stuff to work with. Ideally there should be a steady drop in elevation from the riser to the exhaust outlet otherwise salt water and the chemical soup of exhaust gas condensate will corrode/degrade just about any material if it is allowed to sit there. Can you do anything about the "Low spot " ?