New Holding Tank Inflow

[Dean Strong]

Peggy, et al,

I have a 1990 Hunter 30 with a manual Jabsco head, which is located on the port side, next to the companionway stairs. The holding tank, only 12 gallons, under the aft bunk (in this boat model, the entire stern forms a huge transverse berth). I believe the tank has been relocated to where the batteries were originally located; the batteries are now in the head cabinet immediately adjacent to the head.

I'm considering a much larger holding tank, and one option is to put it back in the head cabinet, and put the batteries back under the rear berth. This is appealing because the entire head cabinet facing comes off, so access for installation would be easy. If I have Ronco custom build a tank for me, it can be quite large. I also can locate the exit fitting on the bottom of the tank, so it can be completely drained (my current fitting on the side of the tank always leaves about 3 inches in the tank, which is more than 10% of my small 12 gallon tank).

If I do this, however, the inflow fitting, which must be on the top (or side near the top) of the tank will be about three feet higher than the head. I'm worried that with normal use, the manual pump will not be able to empty the line between the head and the tank, leaving stuff in the line all the time. Seems like this would be asking a lot of the joker valve, which I'm sure will seep, leaving at least some material in the bowl all of the time.

Currently the line rises only a few inches up and over a bulkhead, then into the tank. The joker valves seeps a little even with that small rise (I'm overdue for a rebuild, scheduled for this fall).

Your thoughts?

Thanks,

Dean Strong
S/V Synchrony

 

[Peggie Hall HeadMistress]

A couple of things...

1. If you'll read a whole bunch of threads pertaining to backflow that have been posted to this forum in the last few months--weeks, even!--you'll save me a whole bunch of work typing the same replies again.

2. Ronco does not build custom tanks, they custom FIT the 400+ tanks in their catalog Ronco Plastics If you need a tank that isn't in their catalog, you'll have to get it from another source and it will cost you a about 4x the price of any tank that is available. If they don't have one that'll fit your space, we can figure out a good place to put one that they do have.

 

[Dean Strong]

Okay, I read the many threads...pump on dry bowl (thats all we use, wetting the bowl with cups of fresh water, vinegar at night, to conserve space) enough times, and even a Jabsco can pump can clear a line clean four vertical feet...

But do you think this is a good idea? Apparently a couple of Beneteau owners don't...

Thanks

 

[Peggie Hall HeadMistress]

Am I reading your question correctly?

But do you think this is a good idea? Apparently a couple of Beneteau owners don't...Thanks

You're asking me if I think that something I recommend is a good idea???

 

[Dean Strong]

Re: Am I reading your question correctly?

Sorry for the amiguity.

I'm asking if you think installing a tank with a three to four foot vertical run up from the bowl is something you would recommend. Is there anything I need to be wary of?

Thanks,

D.

 

[Peggie Hall HeadMistress]

No, I don't...

It can be made to work, but it's not the best idea at all. And I don't know how you got the idea that I do recommend it from reading the previous discussions about how to prevent backflow. So I think you'd better read 'em again.

I just caught something else in your first post... You said "I also can locate the exit fitting on the bottom of the tank, so it can be completely drained..." That will only work if the entire tank is at least a few inches above the waterline at any angle of heel...which could very well put it 3-4' above the toilet.

I sympathize with your need for a larger tank. 'cuz 12 gallons is really marginal...but what you want to do will only trade one set of problems for a different set.

So let's put our heads together and spec out something that will work for you without adding to your problems. Send me a PM or an email (just click on my profile next to this reply to do either) and I'll reply with direct contact info.