Check your wet exhaust hose

[Doug]

I post this message in the hope that others will learn from our experience. Particularly CHB 34 owners.
Last August while cruising a long way from repair facilities I noticed some moisture around exhaust hose in the lazerette. The hose felt a bit soft in that area but fortunately I was able to fix it with a combination of rescue tape and duct tape. No more leaks, monitored it daily when travelling, all was good. Replacing the hose was on the to do list. Finally got to it this week.
On our CHB 34 the hose is only visible in the engine room and the lazarette. The rest of it runs behind cabinets and the water tank on the port side of the aft cabin, not accessible and can’t be checked visibly.
We disconnected the hose at both ends and with great difficult managed to pull it through to the engine room and out into the main cabin. Did we get a surprise! Much of the section from behind the cabinets was very soft and basically disintegrated in our hands. The hose may have been original, don’t know it’s age. I think there is a low point in the hose behind the cabinets and water sitting in there caused it to deteriorate. Both the transom end and the engine end are higher.
We were extremely lucky. Not sure how the hose had not leaked (we have been using the boat). It could have pumped a lot of water into our aft cabin while running and we wouldn’t necessarily have noticed it. The learning point for me - if any part of the exhaust hose is bad, chances are there are other sections that are worse. They may be in areas you cannot see. Replace it now!

 

[Comodave]

Good point. I hope I never have to replace mine.

 

[Insequent]

Given that part of the run is hidden, consider an alternative when you make your repair.

Much of my wet exhaust run is now a fibreglass tube. There are short sections of hose from the water-lift muffler at one end and the transom fitting at the other end. Using rigid tube helps ensure a continuous fall running aft, with no sags.

 

[Doug]

Thanks Brian. Good tip.

 

[sdowney717]

Aft of the vernatone mufflers, I have exhaust tubes made of some kind of black plastic. Short sections of rubber hose slip over this tube to join to the copper tube at the stern where it exits the hull.

Boat built in 1970, I have had the system apart and they are perfect on the inside. In truth, it looks like the entire system is OEM except for the hoses coming off the exhaust manifolds look to have been replaced, but not by me.

Forward of the mufflers are the mixers made of bronze where exhaust and raw water join. Boat has twin v8's.

Exhaust risers are FWC, and a bronze raw water injector takes raw water mixed with exhaust gas into the smaller hoses running to the large mixers.