Replacing Holding Tank

[mregan]

Rick,
I moved my tank inlet to the spot you are suggesting for the same reason.  I also moved my tank pumpout hole from the bottom to the upper side of the tank.  I had Ronco install a pick-up tube to the bottom of the inside of the tank.  Now no more waste sitting in the hose, plus no need to worry about any leaks since all connections are near the top.  Peggy Hall recommended this when I was replacing my tank on my C-30.

[Dave Spencer]

I love mregan's idea about in internal pickup.  This is a very neat solution, especially if you are having a new custom tank made for you.  I had this arrangement on our previous boat - a good old  CS27.   It worked well - until it didn't.  The internal pickup was a light hose that eventiually cracked and it was a tough job to replace it working through an inspection port that was just a little too small.

[Rick Allen]

Thanks Dave for your quick response sir! This why I love this forum. Your answers are exactly what I was looking for.

Megan, thanks for replying. Utilizing an internal pick-up hose is a very interesting idea. I didn't know Ronco was capable of adding this feature. Do you know how it was configured? Does the internal hose "lay" on the bottom of the tank similar to the recent posts concerning the fuel pick-up line? I also wonder if future maintenance of the internal hose might be an issue. Is it replaceable?

I will certainly be contacting Ronco about this idea.

Thanks everyone for your great ideas!

Rick

[Stu Jackson]

Do you know how it was configured? Does the internal hose "lay" on the bottom of the tank similar to the recent posts concerning the fuel pick-up line?

Rick, the concept of the holding tank pickup is opposie of the fuel tank "laying on the bottom" thing.

Essentially, it is a vertical hard pipe that is cut at about 30 to 45 degrees with the tip on the bottom.

[KWKloeber]

Speaking of holding tanks - this may or may not be feasible on the 34, but it's something I added to my 30.  The tank sits high, under the port settee in the saloon.  As we all know, naturally as soon as the black water level drops to the top of the outlet, the discharge hose sucks air and looses its vacuum.

I installed a wet "P trap" after the tank outlet, fabricated from 1-1/2" PVC, with the trap piped toward the bilge -- it lays flat against the hull, so the low end is lower than the tank outlet because it sits closer to the bilge/center line.

So, with the P trap lower than the tank, the suck hose never looses vacuum until the the tank is completely empty.  This  may sound confusing, so I'll try to find a pic of the install and post it.

kk

[mregan]

Do you know how it was configured? Does the internal hose "lay" on the bottom of the tank similar to the recent posts concerning the fuel pick-up line?

Rick, the concept of the holding tank pickup is opposie of the fuel tank "laying on the bottom" thing.

Essentially, it is a vertical hard pipe that is cut at about 30 to 45 degrees with the tip on the bottom.

Exactly what Stu said.   I haven't been at the boat for a bit but I'm pretty sure the pipe is pvc.  You can call Ronco and ask them. 
One thing I will mention if you get the Ronco tank.  I think it's a B134 but I might be mistaken.  I'm going off memory. 
I wanted to move my vent hole on the top of the tank to a different location.  On the old tank, the threaded opening on the vent was recessed into the top of the tank maybe 3/4".  I figured they would do the same on the new tank just move it to where I wanted.  They don't.  The recessed vent opening is in the same spot but they weld/cap it and installed a new threaded vent opening in the spot I wanted except they weld it to the top of the tank so it sticks up 3/4-1" off the top of the tank.  Once I put my threaded to barbed 90* elbow on it, I think I'm going to be hitting the wood cover that goes over the tank.  Just something to look out for.

[Dave Spencer]

mregan.
I hope your vent will fit despite the boss that raises the elbow.  If not and you are close, you could grind down the boss thereby reducing the thread engagement but this shouldn't matter since there is virtually no pressure and foul odours shouldn't leak through the threads.  I measured the clearance on my boat and saw ~1.5" between the tank and the bottom of the port settee.  See pic.  If you aren't close and the boss proves to be too high, I added a vent as shown in reply #18 in this post   http://c34.org/bbs/index.php/topic,6861.15.html  You need an inspection port in the tank to be able to do this but I'm quite happy with my installation.  

FWIW - my tank is marked "RONCO- B179"

Let us know how you make out.