Cracked exhaust mixing elbow

[rwidman]

Originally Posted by matthidinger

Hey folks, I recently purchased my first sailboat, a Nonsuch 26 with a Westerbeke 21 in it. During the survey we found the exhaust mixing elbow was cracked, so the price was adjusted and now it's on me to fix it.

I don't have much mechanical experience but I assumed this would be a relatively straight-forward job to get my hands dirty. Unfortunately I'm being told it might be trickier than I thought. The riser appears to be a custom fabrication, of which I have no idea what condition the pipe is in under the heat wrap, and can't tell whether or not it's welded to the elbow.

The boat is quite far away, so the only thing I have access to right now is the attached photo. It will be a 2-day cruise to her home port of Seattle, so I'd also like to know whether or not something like JB Weld would hold it together until I have a chance to work on her a little closer to home.

If anyone is able to interpret this photo and help me understand if this is a relatively straight-forward fix that I could do myself, and what parts I might need, I would very much appreciate it!


Thank you
-Matt

Is there a reason you can't hire a mechanic or boat yard local to the boat to have it repaired properly?

[Cheechako]

Originally Posted by ErikFinn

PO of one of my previous boats had fixed the aluminium elbow with some epoxy like substance. Not sure obviously exactly with what but I reckon epoxy. Nevertheless, the repair never failed, had hose clamp or two tightened around the patch, but eventually I replaced the elbow with a new one because the "repair" looked sooo hideous!

Re JB weld, there is a YouTube video guy complaining about JB weld not holding up to the temps JB advertise and that a Loctite one is much better. Which exact one can't remember I recall a new product but I won't go for JB next time.

I repaired a heat exchanger with JB weld once, It lasted about one hour at operating temp. I repaired a cracked aluminum V belt pulley with JB weld once, that pulley got too hot to touch under use, it held fine. Go figure.

[captain465]

Auto parts stores used to sell a "muffler bandage", essentially heat activated fiberglass patch. Wind it around the elbow, run the engine to heat the exhaust, and it will seal the crack until you can get the proper part. Or , go to an orthopedic doctor and ask for water activated fiberglass casting material. Almost the same procedure, wet it, wrap it around the elbow, allow it to set up, and your good to go until you get the new part. BTW , the casting material is also good for an emergency hull patch, it will set up under water!

[smilinjac]

I repaired a Catalina 27 exhaust assembly by removing the whole pipe section intact(not as hard as I expected), taking it to a plumber who made a new one for under $100 out of galvanized pipe, and reattaching it to the engine. The flange I removed, put in white vinegar to remove the rust, and repainted with high temp paint. Stainless steel would have been better but I got ten years out of it.....probably more if I had done more freshwater flush. The heat exchanger just order a matching new one and replace. Don't forget to change the zinc in it in the future. Last thing you want is to be motoring along and suddenly find the floor of your cabin covered in water due to a failed patch.

[Caddy Shack]

JB Weld High Heat (bought at Auto Parts Store) worked for me, and I had a dime sized hole in mine. Reinforced with wire mesh. It's not a long term fix but no issues after 6 months of use.

[seahag]

I must be missing something here. A number of replies mentioned fiberglass tape, and JB weld, and epoxies...is there a reason no one talked about using foil tape like that used on home furnaces? It sure seems like a better heat tolerant tape than fiberglass, and I have definitely sealed up some nasty air leaks with the stuff. I have not used it in marine applications or on diesel exhaust elbows, but on cars it works pretty well. It's fairly user friendly although in tight spots it likes to stick to itself and then it doesn't look so pretty.

Anyone with some experience with that on boats? Also-I've never seemed to have any luck with JB weld, though I know a lot of people have. What is it really good for? I've tried to fix broken parts as an adhesive (didn't work) plug leaks in radiators and hydraulic reservoirs, and plastic tanks (worked for a few seconds in each case) and to fix cracks in fan shrouds and other small stuff. Just never any luck.

Sorry I can't help specifically unless the foil tape stuff works for you. Good luck!

[tinkrman69]

That elbow looks pretty bad. A temporary fix would be to get some exhaust repair putty from an auto parts store and some fiberglass cloth, cut it into 2 inch strip coat the elbow all the way around and wrap with the glass coat with more putty to impregnate the glass repeat for 3 or more layers.

I've had this work for almost 100 hours of run time before being able to get parts.

Good luck

[AiniA]

Originally Posted by seahag

I must be missing something here. A number of replies mentioned fiberglass tape, and JB weld, and epoxies...is there a reason no one talked about using foil tape like that used on home furnaces? It sure seems like a better heat tolerant tape than fiberglass, and I have definitely sealed up some nasty air leaks with the stuff. I have not used it in marine applications or on diesel exhaust elbows, but on cars it works pretty well. It's fairly user friendly although in tight spots it likes to stick to itself and then it doesn't look so pretty.

In my case it was a what do you have onboard to fix the problem du jour. Perhaps it would be helpful to have some of that tape in your 'never know what you might need box'.

Anyone with some experience with that on boats? Also-I've never seemed to have any luck with JB weld, though I know a lot of people have. What is it really good for? I've tried to fix broken parts as an adhesive (didn't work) plug leaks in radiators and hydraulic reservoirs, and plastic tanks (worked for a few seconds in each case) and to fix cracks in fan shrouds and other small stuff. Just never any luck.

Sorry I can't help specifically unless the foil tape stuff works for you. Good luck!

I have had considerable success with JB Weld, i.e. 4 or 5 fixes. The biggest problem I have with it is that it is a bit too thin and does not stay in place. After a few minutes you need to go back and pat it into place.

[s/v Jedi]

Originally Posted by AiniA

I have had considerable success with JB Weld, i.e. 4 or 5 fixes. The biggest problem I have with it is that it is a bit too thin and does not stay in place. After a few minutes you need to go back and pat it into place.

You can thicken it with some Cabosil / Colloidal Silica just like every other epoxy

[oldcal46skipper]

It is so refreshing to check in on this forum. Most everyone is very positive and certainly are willing to share their knowledge from experience and formal training.

Some forums have their trolls and snipers who rarely say a good word, so I drop those lists. Life is too short.

Thank all of you for sharing!

To the OP, look at how much knowledge you have gained and learning to appreciate fellow cruisers. There are several temporary solutions to your exhaust challenge. I suggest you study them all, make a decision based on your capabilities and go SAILING. Keep your engine area exhaust fan running, check often and only run the engine for getting away from the dock or anchor.

Let us know how it works out for you. I am sure you can find a competent technician in the Seattle area who can assist you in replacing the mixing elbow.

Tom