Muffler Leak / Noise / Worn Out Base - and you all come through again!

[GYPSEA]

Just wanted to say - Thank you! This group is awesome. I recently had the pleasure of pulling Gypsea's muffler out to see what was going on... First step - to to c34.org and research.
I had recently replaced the motor mounts and oddly didn't get a major reduction in noise..... hummm... then I took the muffler out to fix the inlet tube leak. It was cracked from over tightening. Apparently it had been leaking enough to rot out the front facing 2 screws holding it down to the 2x4 base/ply. Basically the hump hose didn't have to 'hump' at all. The thing rattled like crazy but I never knew exactly where ithe noise came from - suspecting I had the same issue as others after replacing the motor mounts. Thanks to all of your info posted out there - I decided I needed to make the tube replacement as I couldn't find anything out there to purchase. So I grabbed a piece of pvc the right diameter for the id and chucked it in the vise. Put some carnauba wax on it and then a layer of plastic wrap from the kitchen. I cut 3 pcs of cloth 12" x 36". Wet the first piece and proceeded to wrap it around the pvc pulling gently to make it tightly wrapped. A tap on the ground removed it from the long pvc pipe. Cut to size, and glassed it in. In hindsight, I should have used a vinyl-ester resin (to help with potential temp issues). Time will tell. Again thanks for all the help - a special shout out to Stu and all you've posted and guided over the years! These boats are fantastic! This weekend - epoxy coat the galley and head counter tops. Fingers crossed!

[Ron Hill]

GYPSEA : You might want to do like I did and tear out that old piece of plywood and install a new piece of plywood that's pressure treated or exterior grade!  I'm sure that the two fwd lag bolt holes are rounded out!!

A thought   

[KWKloeber]

GYP

see the 2nd from the bottom article under engine>exhaust
https://c34.org/wiki/index.php?title=Diesel_Engine#Exhaust_System

My tube also was collapsing -- I happend to have a pc of aluminum tubing (from what I have no idea) that just was a "tap-in" fit in the ID of both tubes.  That fixed it up nicely. 
That lasted until the weak muffler (tends to crack at the base) leaked twice and finally crapped out on a crossing.  Now I have a stainless muffler.

[GYPSEA]

YES indeed to both posts!.
New 3/4 epoxy coated ply under the muffler. Great suggestion.
Also did thoroughly research all the muffler posts - - that's why you folks are the best - -  fantastic resource!

I can't believe all the things I've done to GYPSEA. I can't believe all the adventures we've had either! Even when I get a little crazy in the head and look at other boats -  I come back to GYPSEA. Best all around boat for Tampa and West Coast of Florida for sure.
Now I just need to remember not to show my excel spreadsheet to anyone (kidding) because it chronicles by date all the things I've done with costs. Ha.
Thank you all again!

[Ron Hill]

GYPSEA : Make sure that you use the SAME lag bolts as the diameter is critical.

You do not want to stress the holes with a larger bolt or redrill making the holes larger in diameter - less you break the top to bottom   
muffler seal !!   

A thought

[GYPSEA]

Thank you Ron! Yes Sir - Same lags.

[Ron Hill]

GYPSEA : You said that your "Hump" hose didn't have a hump?  If you have "hump hose" it should be blue in color and have a visible hump!!  That old black hose was wire reinforced and had NO give to it - hence transmitting all the engine vibrations to that inlet tube cracking it!

You might also check the short hose from the outlet of the heat exchanger to the nipple on the exhaust riser.  If you still have the wire reinforced hose get rid of it!  Replace it with a softer nylon reinforced hose.  That old stiff hose also transmits vibrations and will crack the weld on that nipple!!!   

A few thoughts