Muffler removal through aft cabin

[sloopdog]

I have a 1988 Catalina 34 with the Universal M25xp engine.

My muffler has been leaking slightly at the exit port for awhile and tightening hose clamps hasn't accomplished anything.  With the season slowing down slightly I am going to pull the muffler and either repair or replace it as well as replace the exhaust hose (all original).

My question is, since I have all kinds of things mounted under the sink in the head, has anyone had any luck removing the muffler through the aft cabin port side wood panel?  I'll be pulling the panel anyways to run the new exhaust hose so I figure it might save me some time as opposed to removing fuel filters, hoses, and regulators to try and squeeze it out of the cabinet in the head. 

Thoughts?

[Stu Jackson]

SD,  from my 2015 Tech Note on "Exhaust Riser Replacement:"

Many of the removal articles suggest removing the muffler from the aft cabin hole.  So I did.  It was a BEAST to do.  When the old muffler is moved off its plywood pad and pulled amidships to the area behind the engine, the muffler ports stick up and barely clear the fiberglass lip of the cockpit sole down below.  The wiring harness wires are even lower and are very difficult to reach to lift up to clear the ports.  After the muffler comes past those obstructions, it is necessary to turn (yank!) it 90 degrees clockwise to get it to come far enough aft to get to the "hole" because of the way the hull is shaped compared to the underside of the aft cabin fiberglass.  I strongly urge you to never even bother.  If your ports are too long, you will never get it out that way and will waste a lot of time & energy.  We learned just how easy it is to replace the new muffler through the head door, which we never bothered to remove.  Take the old muffler out through the head door!!!  When installing the new muffler have the ports face midships, tilt it in and down and then flat and back over the plywood base.  It's that easy.



Photos are in the Tech Notes Online

Moving the head sink hoses is easy.

[KWKloeber]

Sloop

Can you tell if it's the port getting crushed by the clamping too tight?
I had that issue and I just happened to have an aluminum tube that was a force fit that I tapped into both tubes to reinforce them.

Do you use a silicone hump hose?

I had other leaks though and eventually took out the Aqualift.

There's an article on the wiki about refurbishing a cracked tube.

[derekb]

Sloop,

I just removed my muffler to replace both tubes. I took it out through the head cabinet door, after removing the raw-water strainer. It came out relatively easily. See a photo of the muffler half-way out in this post:

https://c34.org/bbs/index.php/topic,6728.msg78690.html#msg78690

I'm currently replacing both of the muffler tubes and I added a new drain plug (Catalina Direct part #Z4451 and tap #Z3633). Since my muffler was leaking so badly, it had fully soaked the plywood mounting platform, so I pulled that out too, and I'm making a new one from scratch.

Regards,
Derek

[sloopdog]

Hump hose is hooked up.  I'm leaking from the port that exits the muffler.

I haven't pulled off the hoses yet since I figured I'd like to pull the whole thing out to do any repairs and then assess since it seems like it will last another 30 years after good repair/replacement.

Stu,  I could be wrong but I was thinking there would be room to pull out the muffler from the wall panel the on the port side that covers the fuel tank area, not the access boards that are below the cushions.  Then again, I'm not at the boat and I might be thinking wrong about the wall panel relative to the location of the muffler.  I guess I'll go for the head cabinet exit strategy, maybe I'll be able to scoot it passed secondary fuel filter and electronics.

derekb,  On your pictures it looks like you removed the muffler tubes.  What did you use to replace?  Did you make your own?

Thanks for the input and links everyone.

[derekb]

Sloop,

yes, I replaced both tubes. The inlet tube (short one) almost fell out on its own after I had removed all the silicone sealant. I removed the outlet tube (long one with a 45 degree cut on the bottom end) using a Dremel with a long thin bit (#9910). I cleaned the holes (to expose a clean surface with no exhaust residue) using sandpaper wrapped around a PVC tube.

I read Mark Hamilton's "Catalina 30 Aqualift Muffler Repair" (in the Tech Wiki) and decided to make new tubes myself, a little different to Mark's approach.

I purchased some 32mm outside diameter PVC pipe from the local hardware store, wrapped it with PVC film so it wouldn't bond to the tubes 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.

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), but I decided that the difference in CTE between the aluminium and the fibreglass may cause problems over the next 20 years!

I'm still painting the repaired muffler (one coat to go) so I'll post some pictures once it's done.

Regards,
Derek

[Ron Hill]

Sloop : Back in 1999? I removed and replaced the muffler thru the aft cabin "floor" cutout.  Wrote a Mainsheet tech note article on the "How To".  I didn't have any problems on removal nor on installation. 
Went that way as I didn't want any of the dirty exhaust water inside the muffler to leak out.  Was able to keep it "straight up"!!
As I recall the factory used "scrap plywood" and none of the nails were galvanized!

A few thoughts   

[Stu Jackson]

Sloop : Back in 1999? I removed and replaced the muffler thru the aft cabin "floor" cutout.  Wrote a Mainsheet tech note article on the "How To".  I didn't have any problems on removal nor on installation.  >>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>

Ron, WADR, your Nov. 2001 article says you removed the head sink door to replace the muffler.

I had a completely different experience of removing the old one.  My conclusion is that while helpful, Ron's experience was simply DIFFERENT than mine.  This quote from my 2015 Tech Note actually mentioned the real date of Ron's helpful article, but what worked for him may NOT work for you. 

There is an easier way, as my first excerpt stated.

I understand his concern about dropping dirty water, but the physical REALITIES of trying to get the danged BIG BOX muffler out of the aft cabin HOLE is simply not worth it because of the POTENTIAL HEIGHT of the tubes. 

If it's hard to get out of the hole, it may well be completely impossible.

Your boat, your choice. 

Muffler & Exhaust Riser Replacement - 2015

There have been quite a few Mainsheet articles and C34 Tech wiki posts about the work involved in these tasks.  Ron Hill's classic November 2001 Tech Notes detailed his muffler replacement.  My own February 2004 Tech Notes discussed our first riser replacement at 1,390 engine hours.  This article discusses the lessons learned and Tips & Tricks of the work that my son, Morgan, and I did in September 2015 at 2,938 engine hours, 1,548 hours after our last new riser.

Muffler:  The inlet and exhaust ports of our OEM muffler had been deteriorating for many years and had begun to seriously leak.  Of course, we had installed the hump hose when we did our first exhaust riser replacement in 2003.  I had reported on the Forum that I had attempted to rebuild the inlet port with Marine Tex, and that Morgan and I had replaced our 17-foot long exhaust hose in February 2012.  The exhaust port was not so bad.  We were able to obtain a replacement muffler for just the cost of shipping ($40) thanks to Rob Hathaway, a generous fellow sailor from Connecticut who was repowering his Catalina 30, and had made his old muffler available to us.  A new muffler from Catalina Direct is $375.

Old Muffler Removal Tips & Tricks:  After removing everything from the aft cabin, I spent a day removing the heat exchanger and taking out the four screws holding the old muffler down.  We took an old cushion and laid it over the prop shaft.  Many years ago I bought a small ratcheting screwdriver to use on the hard-to-access screws on our old head.  This tool was invaluable.  It is one with a small opening that takes different screw bits and holds them at a right angle to the short handle.  I bought it at Ace Hardware.  Trying to get a regular screwdriver on these muffler screws is almost impossible and it worked great for removing and replacing those four screws.[/b][/b]

Please read my entire article in the 2015 Tech Notes.

If you don't have access, please join the C34IA.  Please.

[Ron Hill]

Guys : Stu makes a point and I've said it many times, "All production Catalinas are not identical". 
In this case Stu has a 1st year 1986 C34 and mine is a 3rd year 1988 production. 
The placement of the muffler? the aft cabin "floor"?  the floor cutout? etc. may all be different!?

A few thoughts