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SM holding tank internal details

Mike Ondra
 

After years of various issues with the metal parts of the holding tank assembly, it seems we are now facing their complete failure. Pumpout now does not remove contents, indicative potentially of a breach in the pumpout riser tube that should be sucking contents from the bottom of the tank. Disconnection of the supply hose from the pump discharges nearly the entire contents of the holding tank into the boat (less than pleasant), perhaps indicative of a breach in the supply riser tube which should be directing the effluent to near the top of the tank. Seems like a double failure at this point.

So, does anyone have drawings, pictures or even knowledge of the 2 risers inside the tank? I have heard them referred to as bronze, but I suspect copper from what I have seen. Has anyone replaced them in their entirety? We have, over the years replaced the tailpieces that connect to their respective hoses with plastic pipe secured to the tank with epoxy (a solution that worked for the corroded/eroded original bronze/copper tailpieces), but have done nothing that reaches inside the tank.

I have not seen any postings on replacement of interior riser tubes, so if anyone has experience/images please reply.

Thanks,

Mike Ondra

Aletes SM2000 #240

Manual Jabsco head pump

Mark McGovern
 

Mike,

Thankfully, I have not needed to tackle this job yet.  However, I did remember seeing a post by Gary Silver posted that had a sketch of his holding tank system.  You can find it here:  https://amelyachtowners.groups.io/g/main/files/Amel%20SM%20Holding%20Tank%20Plumbing%20Diagram/Holding%20Tank%20Plumbing.pdf

There is also a lot of information in this photo folder:  https://amelyachtowners.groups.io/g/main/album?id=84526

Good luck!


--
Mark McGovern
SM #440 Cara
Deale, MD USA

Mike Ondra
 

Hi Mark. Thanks. And this is for others who may have a configuration nearer to ours.

 I believe the pumpout riser is probably the same. However In our hull #240, with manual pump, the riser from the toilet enters the bottom of the tank and apparent continues inside the tank to discharge near the top. That is the piece I am trying to get a handle on. Perhaps this riser is external in later models, a hugely better idea.
Mike

On Dec 12, 2019, at 2:08 PM, Mark McGovern <mfmcgovern@...> wrote:

Mike,

Thankfully, I have not needed to tackle this job yet.  However, I did remember seeing a post by Gary Silver posted that had a sketch of his holding tank system.  You can find it here:  https://amelyachtowners.groups.io/g/main/files/Amel%20SM%20Holding%20Tank%20Plumbing%20Diagram/Holding%20Tank%20Plumbing.pdf

There is also a lot of information in this photo folder:  https://amelyachtowners.groups.io/g/main/album?id=84526

Good luck!


--
Mark McGovern
SM #440 Cara
Deale, MD USA

Mark McGovern
 

Mike,

I have what I would call a "European" spec SM so I don't even have a pumpout riser in my holding tank at all.  I just have a hole in the deck with a plug.  I actually had to make a hose with a pumpout fitting on the end of it in order to pump out the holding tank.  I call it my "poop straw". 

In the photo album link I sent Bill Rouse has a sketch of his holding tank where he shows the inlet to the holding tank being a straight 38mm bronze pipe that is glassed into the holding tank at the bottom of the tank and extends upwards towards the top of the tank:  https://amelyachtowners.groups.io/g/main/photo/84526/12?p=Created,,,20,2,0,0

This is the setup that I seem to have on Cara.  There are also several pictures of completely corroded outlet pipes in the folder.  One could only surmise that the inlet pipes will suffer the same fate and that it is only a matter of time before we all will be replacing these.  

--
Mark McGovern
SM #440 Cara
Deale, MD USA

Duane Siegfri
 

I just did the hose and valve replacements.  

The deck plug on Wanderer is the same as Mark describes.  However the tank is shaped like this as you look horizontally:
____________
|                      |
|                ___|
|                /
|              /     i
|______/      n
   o    
   u    
   t
So in the older versions Amel avoided the long interior input pipe by reshaping the tank. it's interesting to see what generational changes they made as time went on.

It seems like the only difference between changing the outlet pipe and the long input pipe would be trying to reinforce the connection so the pipe would resist the sloshing of the contents and stay upright.

Duane
Wanderer, SM#477