My son and I just finished replacing the transmission fluid and installing a new heat exchanger bracket on our M25. As we were sitting admiring our work after we cleaned up, and with a toast to his hard work ( :D!!!), I said: "What's next? Well, this really nice guy on one of the boards has shown us what we need to know about our mufflers. That's next!"
He just smiled... :abd:
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Here's a link to a great thread from co.com. Thanks to Claude for doing the forensics on an old Catalina 34 muffler.
Now you know what's inside!
http://forums.catalina.sailboatowners.com/showthread.php?t=135675 (http://forums.catalina.sailboatowners.com/showthread.php?t=135675)
The topic starts with water pumps, but there are two great pictures further down that Claude has posted that are really helpful.
There's also a link to the Catalina Direct muffler replacement page. http://www.catalinadirect.com/index.cfm?fuseaction=product.display&product_ID=2434 (http://www.catalinadirect.com/index.cfm?fuseaction=product.display&product_ID=2434)
I remember that Ron had changed his muffler out some time ago and wrote a superb report on it.
For C34IA Members, here it is, November 2001 Tech Notes: http://www.c34.org/mainsheet/pdf/Nov-2001.pdf (http://www.c34.org/mainsheet/pdf/Nov-2001.pdf) (I found it quickly using the "Knowledgebase" xls file.)
Great information Stu. Thanks. I haven't observed any hint of corrosion on the muffler on our 1994 boat. It has always been in fresh water which I imagine would mitigate the issue. I assume Claude's C-34 friend is in salt as are you and Ron. Has anyone heard of a muffler failure resulting in a very messy flooding of the boat?
Muffler inspection is something I'll put on my "list of things that work fine and should still be good but I better check it and possibly mess it up". I assume most boat owners have a list like this. Ron's excellent description of replacing his muffler and his exhaust hoses in the Tech Notes will come in very handy someday.
Here's what my muffler looked like when I had the boat surveyed before we bought it last year. Some dirt on it and no coolant in the overflow bottle... both fixed now.
Guys : Stu that was a good site with a picture so I can explain a few things :
1. Reason the left inlet is broken off is because of the stiff inflexible hose from the metal exhaust riser to the muffler. The fix is very simple - the hump hose to take up the engine vibration transmitted thur the metal exhaust riser. The hump hose absorbs that vibration rather than the inlet tube to the muffler, which you see broke off!!
2. Why the rust? My best guess is that the stiff WIRE reinforced hose from the riser to the muffler inlet has an interior failure and the wire reinforcing is rusting away!! Other wise there is no other ferris metal (that I can think of) in the raw water system. Possibly a non stainless hose clamp?
A few thoughts
Quote from: Dave Spencer on December 15, 2011, 05:51:34 PMIt has always been in fresh water which I imagine would mitigate the issue. I assume Claude's C-34 friend is in salt as are you and Ron.
All I can say is this:
Water corrodes...salt water corrodes absolutely.
The concept that only salt water boats have "issues" is pure fantasy.
It just takes longer (about a week per year, but that's just my guess from reading about it for the last 30 years)...but that has nothing to do with the water, it has to do with the skipper's attention to detail and maintenance.
Quote from: Dave Spencer on December 15, 2011, 05:51:34 PM
1. Has anyone heard of a muffler failure resulting in a very messy flooding of the boat?
2. Here's what my muffler looked like when I had the boat surveyed before we bought it last year.
Dave,
1. No. Dirty maybe, but total flooding? No - 'cuz the way it works is only if the engine is running, right?
2. OOOPS!!!! You do NOT seem to have have the hump hose. That stiff black hose into the inlet of the muffler is exactly what we're trying to point out. Get a Hump Hose. Reduce the strain on the inlet port of the muffler.
Like this: http://c34.org/bbs/index.php/topic,5617.msg35260.html#msg35260 (http://c34.org/bbs/index.php/topic,5617.msg35260.html#msg35260) This is a VERY, VERY good discussion of hump hoses and mufflers and exhaust risers. EVERYONE SHOULD take the time to read the entire thread.
Dave : I also have never heard of a boat flooding either, for the same reason that Stu mentioned. However, it could make quite a mess and the exhaust smell would be prevalent.
That's why I always recommend that people go down below and look at the engine while its running (thru one of the side doors). I also open the door under the head sink and look at all fittings, especially the raw water strainer.
As far as your boat being in fresh water. The hull may be, but the muffler and exhaust hoses if full of water that has been aerated with very corrosive exhaust gasses!! A few thoughts
Claude has just posted an interesting repair idea. Click on the pdf file to view.
1. Is it possible to add a hump hose without removing the riser?
2. In the fix proposed in the pdf, why not use stainless? Brass won't last long in that environment.
T
Quote from: 2ndwish on December 16, 2011, 04:01:10 PM
1. Is it possible to add a hump hose without removing the riser?
2. In the fix proposed in the pdf, why not use stainless? Brass won't last long in that environment.
1. Please read the link in Reply #4. Yes, I have, because the exhaust riser screws into the flange at the engine end. I end up with a little blow-by because the threads in the flange are not machined for anything like a "line up" for the horizontal run of the riser to under the head sink. Even though I used muffler patch paste on the threads, that material has been blown out. I've never quite understood the "line it up and assemble it all" concept.
Added 2/5/2016 - Having again replaced the exhaust riser (see Tech Notes) I get it now. One must tighten the riser onto the flange with a vice, a BIG one! But you can manage to get the hump hose on if you judiciously measure and cut it to fit, if necessary. My new riser position under the head sink didn't require me to cut the new hump hose at all.
2. Good idea, why not ask Claude at the link I provided? Please, don't shoot the messenger. :D
2nd : From many Mainsheet tech articles and posts we have stated you can easily add the hump hose with the riser in place.
The whole idea of the hump hose is so you NEVER have to go with Claude's fix.
Even with that fix I'd still recommend that a hump hose installed - as the vertical vibration on any inlet tube (original or fixed) is bound to cause fatigue and eventual failure !!
I've read that stainless is not a good metal for exhaust systems because the chemical composition of exhaust reacts badly with the stainless.
Stu and Ron,
Thanks for the feedback. I like the idea of the softer hump hose and will work on that this year.
I hope my comments weren't taken to mean that fresh water sailors get off scott free with maintenance and have no issues... clearly not the case.
I agree that major flooding in case of failure of the muffler seems unlikely to go undetected almost immediately due to the smell and the obvious change in sound one would expect from the engine. I regularly inspect what I can of the engine immediately after startup and every hour if we are making a passage of more than an hour long under power. My trusty handheld temperature gauge is useful to monitor the health and consistency of many systems. I regularly sniff for unusual fuel or exhaust fumes, inspect the Racor and shoot the temp on the stuffing box, exhaust hoses, alternator body and alternator belt from the head access hatches.
Dave, I agree.
The result of an exhaust riser failure, at least at the nipple, was included in my February 2004 Tech notes report, here for C34IA members: http://www.c34.org/mainsheet/pdf/Feb_2004.pdf (http://www.c34.org/mainsheet/pdf/Feb_2004.pdf) The billowing black/brown smoke filling the cabin and pouring out of the companionway was a dead giveaway! :shock: [Please note that the article says I didn't use hump hose - I corrected that shortly after the article was published.]
Much the same results would be expected if the inlet or outlet lip of the muffler failed catastrophically. That, however, doesn't seem to be the case, because the muffler lips tend to fail slowly over time. What we've learned from Claude's forensics is what the muffler is made of, since most of us simply get to see the white fiberglass cover.
There have been many posts here over the years on rebuilding those lips, because many of us have had leaks where the hoses join the muffler. Whether or not the steel insert has failed or just the fiberglass surrounding it at, most usually, in the inlet lip, has yet to be determined on my boat.
The very important information from Claude's presentation will be helpful for me in deciding what to do next.
As Ron reported (in the link I provided) both he and Claude decided to remove and replace the muffler, and explained, very well, just how to do it. Ron also did a presentation on how to replace the exhaust hose from the muffler to the transom.
With all this information, I think all of you now can best assess and determine your own next steps when it comes to that system.
Like folks who still have the old trailer connections and ammeters in their wiring harnesses, I find it interesting that many still have those old solid hoses on the inlets to the muffler instead of the far superior hump hose. But note, I've had a hump hose on mine since 1998 and have still found major deterioration of the inlet lip.
"Your boat, your muffler" :D :D :D
Quote from: scotty on December 16, 2011, 07:12:01 PM
I've read that stainless is not a good metal for exhaust systems because the chemical composition of exhaust reacts badly with the stainless.
Scotty, the Catalina Direct and Catalina Yachts replacement exhaust risers are made of stainless. Many have reported on making up their own with black steel. Check the wiki and the Knowledgebase: http://c34.org/faq-pages/faq-exhaust-pipe.html (http://c34.org/faq-pages/faq-exhaust-pipe.html). My CY ss exhaust riser has been in since 2003, noted in the report I linked to earlier in this topic.
Scotty : I surely don't know where you read that stainless is not a good metal for exhaust systems ? What are practically all of the auto mufflers and exhaust pipes made of today?? - stainless!!
I've got a 17 soon to be 18 year old Taurus SW that has the original stainless exhaust system !! I was also the owner of a LTD SW that ate galvanized mufflers every couple of years!!
If you look back in the old Mainsheet tech notes you 'll find that Dave Davis and I attempted to make a survey on the early C34s that had the old iron exhaust risers and the stainless risers. Most problems with the stainless risers is in the welded joints not the solid pipe.
As Stu mentioned that old "black pipe" (like they use in gas lines) was the industry standard of that day until they changed to the longer lasting stainless.
A few thoughts
I think Claude's fix is a good one. Either brass or stainless should last for years. I would make it a permanent fix, by epoxying the assembly in place, I don't trust that the bolts through the fiberglass would hold. If it was decided to use RTV so that it could be easily changed in the future, I would suggest welding 1/4x20 nuts onto fender washers and epoxy them in place on the inside of the muffler.
2ndWish. Yes the hose can be changed. The hardest part is getting the old one off. I took a hacksaw and cut out the center section between the bottom of the riser and the top of the muffler. Then use the hacksaw to cut the top section off the riser, make a vertical cut, then pry with a large screwdriver to break the hose loose. The bottom is a bit harder because of the fiberglass. I used a sharp knife and started cutting the rubber again almost vertically. When you get to a wire jump over it and cut some more. When your through cutting use wire cutters to clip the wires. You may need to cut somemore rubber away to get access. Clean the exposed muffler and riser. Lube the inside of the new hump hose with dish soap, slide it as far up the riser it will go, then man handle it onto the the muffler and slide down. I put the clamps on first, the top can be loose around the top, the hump will hold it. The bottom one I expanded and slid over the muffler input and left it on the top of the muffler, when the hump hose was in place, lifted and tightened. Ron suggests putting a piece of leather between the clamps and the soft hump hose to keep from gouging the hose. A Dremell with the proper bit is a much better tool to use, just don't have one in my tool box.
Ken- Thanks. Now which length of hump hose did you use?
T
I don't remember. I think I measured the old one and got the one that was the best fit.
2nd : You need to get the 9".
Then you might have to cut it shorter to match your length needed for your boat.
If I remember correctly, brass is not good around sea water. Use bronze or stainless, not brass.
Larry
Quote from: Fuzzy on December 20, 2011, 08:34:35 PM
If I remember correctly, brass is not good around sea water. Use bronze or stainless, not brass.
Larry
That is true. Zinc is an alloy of brass and zinc is very quickly electrolysed in salt water. :cry4`
Bronze is copper/tin sometimes including phosphorus, manganese, aluminum and silicon.
Brass is generally about 70%copper/30%zinc and sometimes aluminum, arsenic, manganese, silver, tin, iron, nickel and/or lead. There are 20-30 different brass alloys.
DR or DZR brass with 1% tin, (dezincification resistant) intended for harsh corrosive (the sea) environments.
Here's another repair writeup, quite good.
http://forums.catalina.sailboatowners.com/showthread.php?p=1167000#post1167000 (http://forums.catalina.sailboatowners.com/showthread.php?p=1167000#post1167000)
Click on the PDF for the whole story, nice presentation, too.
Quote from: Stu Jackson on December 01, 2014, 11:42:14 AM
Here's another repair writeup, quite good.
http://forums.catalina.sailboatowners.com/showthread.php?p=1167000#post1167000 (http://forums.catalina.sailboatowners.com/showthread.php?p=1167000#post1167000)
Click on the PDF for the whole story, nice presentation, too.
BTW, owners don't always understand the need for / inner workings of a wet exhaust & water lift muffler -- here's a great article from my friend / all knowing Jerry Powlas:
http://www.pearson35.com/p35articles/documents/Exhaust_.pdfKen K
Well, the time has come to repair my WaterLift muffler!
It's been leaking ever since I purchased the boat over a year ago, and tightening the hoses was not doing anything to help (just crushing the tubes a little more each time!).
All the discussions on here on the Message Board and articles in the Tech Wiki are most useful, so I've started the process of repairing the cracked/crushed inlet pipe and the cracked outlet pipe.
As advised by "those who know", I removed the muffler through the cabinet door under the head sink. I needed to remove the raw water strainer to make room. Removal was made a little more difficult by the wooden supports coming along with the muffler. Twisted it sideways and out it came:
(https://live.staticflickr.com/65535/46775539475_79eeb9a8ab_c.jpg)
(https://flic.kr/p/2egoSfx)IMG_0728 (https://flic.kr/p/2egoSfx) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
With the muffler back at home, the delightful repair attempt made by the previous owner became apparent. That's about an inch thick of silicone sealant! And still leaking!
(https://live.staticflickr.com/65535/46775538715_1db294d375_c.jpg)
(https://flic.kr/p/2egoS2r)IMG_0734 (https://flic.kr/p/2egoS2r) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
The build-up of silicone sealant was removed using a wood chisel (it all came away from the gel-coat surface of the muffler very cleanly) and with some gentle squeezing and twisting the inlet pipe was freed. Not much of the bonding surface was actually bonded (maybe 20% remaining!). Here is the inlet pipe sitting on top:
(https://live.staticflickr.com/65535/47691535431_423a6ba7da_c.jpg) (https://flic.kr/p/2fEkzWg)
IMG_0743 (https://flic.kr/p/2fEkzWg) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
More to come...
Derek
You might find this repair useful....
http://c34.org/wikiwp/?rdp_we_resource=http%3A%2F%2Fc34.org%2Fwiki%2Findex.php%3Ftitle%3DRepairing_an_AquaLift_muffler_%28with_pictures%29
Thanks Ken, yes I've already downloaded that one. :thumb:
Articles like that give us all the confidence that we can make such repairs! :D
OK, I've finally finished repairing my muffler. Both tubes have been replaced with new tubes which I made myself. I've added a generous fillet at the base of each tube. The new style drain (from Catalina Direct) has been drilled, tapped and installed.
The photo below shows my pressure testing setup - a section of bike tube clamped over the inlet and outlet tubes, then pressurised using a bike pump. I gave it about 20 pumps and then submerged the muffler in my pool to look for air leaks. On my first test I found a leak (small hair-line crack in one of the lower edges). This was then repaired and tested again, leak free now!
(https://live.staticflickr.com/65535/48926512307_39eb4f6fd0_c.jpg) (https://flic.kr/p/2hxtax2)
IMG_1477resize (https://flic.kr/p/2hxtax2) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
Next task is to remove the remains of the damaged muffler mount and then put the repaired muffler and new mounting plate back into place in the boat...
Well I guess you have the Midas touch.
Very nice job
Looks like factory piece.
Wonder how carbon fiber tube would hold up.🤔
Quote from: derekb on October 22, 2019, 03:45:11 AM
OK, I've finally finished repairing my muffler. Both tubes have been replaced with new tubes which I made myself. I've added a generous fillet at the base of each tube.
Looks great! What material did you make the tubes out of? How long are they, and did you re-gelcoat over repair?
That rebuild is outstanding!!! You may want to relocate that muffler on deck....seems a shame to hide it under the bathroom sink.
Seriously though, the finish looks like gelcoat, and I do like the idea of the reinforcing fillets for added strength at the joints.
I wrapped the new tubes myself. I purchased some 32mm outside diameter PVC pipe from the local hardware store, wrapped it with PVC film as a release layer, then wrapped about 8 layers of 300 gsm 0/90 fibreglass cloth around the pipe. I soaked the fibreglass with West System 105 epoxy before wrapping. I placed the soaked fibreglass on a flat surface and rolled the tube from one end, squeezing out as much resin as possible as I rolled. Then I wrapped the wet tube with peel ply, again squeezing out as much resin as possible. After curing the PVC tube came out easily. I sanded the outside of the tubes down to the correct diameter using a disk sander and using the 32mm PVC pipe as a mandrel on which to spin the wound tube.
I glued the new tubes back into the muffler body with thickened epoxy and built up a large radius fillet to strengthen the joint.
I did consider wrapping the fibreglass tubes around an aluminium tube and leaving the aluminium tube in place as an anti-crush sleeve (as suggested by Ken K in another thread), but I decided that the difference in CTE between the aluminium and the fibreglass may cause problems over the next 20 years.
The repaired muffler was painted with one-pack epoxy paint (also from the local hardware store, Bunnings - equivalent to Home Depot).
Tube lengths were as listed on the Catalina Direct website:
(https://www.catalinadirect.com/images/products/2434/F7970_S02_3100_lg.jpg)
Here's another shot of the repaired muffler, alongside its new mounting plate. The mounting plate bearers have not yet been trimmed to size, they need to be cut to match the angle of the inside of the hull...
(https://live.staticflickr.com/65535/48949435206_88e842f169_c.jpg)
(https://flic.kr/p/2hzuDHq)IMG_1425resize (https://flic.kr/p/2hzuDHq) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
Nice shop porn
Outstanding Derek
Did you slice open the body and do any work on the bottom seam, or just handle the inzie/outzie from above?
I've thought (dreamt) that if I had decided to repair mine (the 2nd time) I'd take it apart to clean up the inside and "float" a good resin fillet around inside after reassembling it.
ken
Ken, I was tempted to slice off the bottom and give the muffler a thorough overhaul, but I decided not to go that route. The new tubes were inserted from the top.
To repair the leak in the bottom edge seam, I just machined out a groove (around 1/8" wide by 1/2" deep by 3" long) where the split seam was visible (it looked like a surface scratch, but the leak-test showed it was more than that) and filled it again with unfilled West System 105 epoxy.
OK, enough of the shop-work... time to get this muffler into the boat.
(Eric, if I mounted this on the deck it would make everything else look "tired and worn"!... :D)
Here are a couple of pictures of the repaired muffler and the new mounting base placed in position to check everything before gluing. This shows why it is difficult to get the muffler out via the aft double-bed opening: even though it looks like there is lots of room, the two pipes are already protruding above the bottom of aft bed molding. And you have to lift the muffler up by about half an inch to clear the mounting plate. So tilting it forward doesn't give you enough room to clear the pipes under the aft bunk molding. At least that was the case on my boat... as Stu says, there are a lot differences boat-to-boat...
The view from under the aft bed, looking forward:
(https://live.staticflickr.com/65535/48981904653_ffd1498c48_c.jpg)
(https://flic.kr/p/2hCn4Kt)IMG_1496resize (https://flic.kr/p/2hCn4Kt) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
And the view into the head basin cabinet, looking aft:
(https://live.staticflickr.com/65535/48982462736_a8de92c36f_c.jpg)
(https://flic.kr/p/2hCpVDA)IMG_1490resize (https://flic.kr/p/2hCpVDA) by Derek Buckmaster (https://www.flickr.com/photos/46332425@N04/), on Flickr
I decided to attach the muffler to the base with a super-large hose clamp (cut in half), rather than the 4 screws in the corners.