E29 exhaust replacement

[Katie Jennings]

Hi,
Now that the water jacket cover is repaired (thanks all!) on my E-29 w/A-4, I need to replace the exhaust. Any tips? Attaching 2 photos....

 

[toddster]

How have you determined that the exhaust is leaking? On which part is the leak? What's visible looks fairly new, as do the hoses and insulation. In any case, the standpipe is slightly different than the original 1971 unit that was on my boat. (On second thought, it is pretty much the same, except that galvanized bit sticking out.)

If it's just the gasket at the flange, that's a simple replacement. If the leak is in the hot section, you can build a new hot section from black iron pipe from a plumbing supply store. They might have nipples of the right length in stock or they will cut threads in pieces cut to your specification. You might need to buy a new flange adapter (Moyer) because it's generally impossible to unscrew any of the used parts. There is usually a plumber's union in the middle of the hot section, under the insulation (otherwise you would never be able to install it.) It's in the most awkward location possible, down in the bottom of the plywood box in the sail locker. It's remotely possible that the union could come loose from vibration and just needs to be tightened. I wouldn't hold out much hope for that though.

If it comes down to replacing the stand pipe, the choices are to take the diagram from the back of the manual to a machine shop and have them weld up a new one from iron pipe, or buy a "Tartan Style" stainless steel one from Moyer Marine. The Moyer one fits almost exactly the same, except the exhaust hose attaches lower and the final hot section pipe may need to be a slightly different length.

Just a final thought - the one bit of the standpipe that is visible appears to be galvanized pipe (though maybe that's just an external fitting?) Exhaust parts, including the hot section, should not be made from galvanized pipe because the exhaust is hot enough to vaporize the zinc coating. (Don't ask me how I know ) The vapor is quite toxic, at least with prolonged exposure, but even brief exposure should probably be avoided if possible. However, this eventually burns off and then it works just like black iron. But if it were sorta new, then it might still be in the process.

You'd probably have to unwrap the insulation tape to see what's going on there. Replacing it is a really, really tedious job. Unless you have a trained monkey available.

 

[Kenneth K]

Speaking of..... where can I get that type of exhaust wrap? I can only find the narrow stuff used in household fireplace/stove inserts.

 

[toddster]

Speaking of..... where can I get that type of exhaust wrap? I can only find the narrow stuff used in household fireplace/stove inserts.

Any auto parts store. Amazon.

Amazon.com : Exhaust pipe wrap

www.amazon.com

My original standpipe had some custom-sewn insulating jackets (with asbestos?) They didn’t come off whole. I’ve seen them in a few other applications but IDK where to get them. BTW, the worst corrosion, the part that looked like Swiss cheese, was under the custom insulation cap.)
edit: it was this sort of thing. Maybe a factory perk?

 

[Katie Jennings]

How have you determined that the exhaust is leaking? On which part is the leak? What's visible looks fairly new, as do the hoses and insulation. In any case, the standpipe is slightly different than the original 1971 unit that was on my boat. (On second thought, it is pretty much the same, except that galvanized bit sticking out.)

If it's just the gasket at the flange, that's a simple replacement. If the leak is in the hot section, you can build a new hot section from black iron pipe from a plumbing supply store. They might have nipples of the right length in stock or they will cut threads in pieces cut to your specification. You might need to buy a new flange adapter (Moyer) because it's generally impossible to unscrew any of the used parts. There is usually a plumber's union in the middle of the hot section, under the insulation (otherwise you would never be able to install it.) It's in the most awkward location possible, down in the bottom of the plywood box in the sail locker. It's remotely possible that the union could come loose from vibration and just needs to be tightened. I wouldn't hold out much hope for that though.

If it comes down to replacing the stand pipe, the choices are to take the diagram from the back of the manual to a machine shop and have them weld up a new one from iron pipe, or buy a "Tartan Style" stainless steel one from Moyer Marine. The Moyer one fits almost exactly the same, except the exhaust hose attaches lower and the final hot section pipe may need to be a slightly different length.

Just a final thought - the one bit of the standpipe that is visible appears to be galvanized pipe (though maybe that's just an external fitting?) Exhaust parts, including the hot section, should not be made from galvanized pipe because the exhaust is hot enough to vaporize the zinc coating. (Don't ask me how I know ) The vapor is quite toxic, at least with prolonged exposure, but even brief exposure should probably be avoided if possible. However, this eventually burns off and then it works just like black iron. But if it were sorta new, then it might still be in the process.

You'd probably have to unwrap the insulation tape to see what's going on there. Replacing it is a really, really tedious job. Unless you have a trained monkey available.

Wow, Toddster this is a fabulous reply. It appears the leak is from the flange. There's a continual, light wisp of smoke coming up from right around there. I suppose it could also be coming from a leak in the wrapped section of pipe aft of the flange (is that what you call the "hot section?"

So it sounds like the order of business is 1) unwrap the pipe to see what condition it's in; 2) remove the flange and check the gasket (this may be easier said than done, though I have doused it a few times with PB blaster with this in mind); 3) order or custom build the necessary parts; 3) put it all back together. Does that sound about right?

 

[toddster]

Pretty much what I'd do. Maybe the flange bolts just need to be tightened? Although escaping gas might erode the gasket to the point that it needs replacement. BTW, if you can get the gasket out whole, they may be able to match it at a local auto parts store. Maybe. (Old guy: "Oh, that's the same as an old flat-head Ford." Pimply young guy "Um, what model of car did it come from?"). Or you can send away for one from Moyer. But keep in mind that, "a light wisp" could be just moisture (or pipe coating?) burning off. I suspect exhaust gas would make a forceful jet.

I kind of worried about that connection because absent some sort of bracket on the stand pipe, the entire exhaust structure just hangs sideways from those two bolts (or studs). Seems like a lot of stress on the joint and the gasket. You might be able to support that exhaust hose a little better, especially if you could rotate the standpipe a bit. But there's probably no way to get a wrench on that joint in situ. (I would not put a pipe wrench on the water jacket.) The PO of my boat had wedged an old swim fin between the pipe and the box, apparently as a vibration damper. I fastened the bracket on my new SS stand pipe to the bulkhead, using a couple of rubber appliance feet under the washers as vibration dampers. It doesn't seem to vibrate though.
BTW: you don't need to wrap the water-jacketed part of the stand pipe. You could use that extra tape to double up on the hot section. The top of the standpipe, above the exhaust hose, per the original design, does need insulation though. That's where mine rotted through.

 

[Kenneth K]

So it sounds like the order of business is 1) unwrap the pipe to see what condition it's in

Use a mask and gloves when unwrapping the old heat wrap. The new stuff is made of fiberglass and the instructions say to wet it before installing to minimize dust/airborne particles.

Whether or not the old stuff contains asbestos is anyone's guess.

 

[Katie Jennings]

Use a mask and gloves when unwrapping the old heat wrap. The new stuff is made of fiberglass and the instructions say to wet it before installing to minimize dust/airborne particles.

Whether or not the old stuff contains asbestos is anyone's guess.

Thanks Ken, good safety tip. Did I see you're in Gig Harbor? Are you racing in the West Sound Series? I'll be in Port Orchard this weekend aboard my friend's J-80 "Crazy Ivan."

 

[Katie Jennings]

Pretty much what I'd do. Maybe the flange bolts just need to be tightened? Although escaping gas might erode the gasket to the point that it needs replacement. BTW, if you can get the gasket out whole, they may be able to match it at a local auto parts store. Maybe. (Old guy: "Oh, that's the same as an old flat-head Ford." Pimply young guy "Um, what model of car did it come from?"). Or you can send away for one from Moyer. But keep in mind that, "a light wisp" could be just moisture (or pipe coating?) burning off. I suspect exhaust gas would make a forceful jet.

I kind of worried about that connection because absent some sort of bracket on the stand pipe, the entire exhaust structure just hangs sideways from those two bolts (or studs). Seems like a lot of stress on the joint and the gasket. You might be able to support that exhaust hose a little better, especially if you could rotate the standpipe a bit. But there's probably no way to get a wrench on that joint in situ. (I would not put a pipe wrench on the water jacket.) The PO of my boat had wedged an old swim fin between the pipe and the box, apparently as a vibration damper. I fastened the bracket on my new SS stand pipe to the bulkhead, using a couple of rubber appliance feet under the washers as vibration dampers. It doesn't seem to vibrate though.
BTW: you don't need to wrap the water-jacketed part of the stand pipe. You could use that extra tape to double up on the hot section. The top of the standpipe, above the exhaust hose, per the original design, does need insulation though. That's where mine rotted through.

Interesting questions. I also wondered if the "light wisp" (which began as a big cloud and quieted down after an hour of idling at the dock) might be from the PB blaster I squirted on the flange bolts in preparation for removing it. The wrapping fabric is damp.

 

[Kenneth K]

Thanks Ken, good safety tip. Did I see you're in Gig Harbor? Are you racing in the West Sound Series? I'll be in Port Orchard this weekend aboard my friend's J-80 "Crazy Ivan."

Yep, I'm out in GH.

Hah, I haven't been in a sailing race since 1991. Have fun!

 

[Katie Jennings]

Interesting questions. I also wondered if the "light wisp" (which began as a big cloud and quieted down after an hour of idling at the dock) might be from the PB blaster I squirted on the flange bolts in preparation for removing it. The wrapping fabric is damp.

Does it help the diagnosing to know that the "light wisp" evaporates quickly? It's not smoky. And the damp wrapping... where is that moisture coming from? I guess we'll find out soon.