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I have a holding tank without the ability to pump overboard. We hope to move aboard and cruise in areas where there are no pumpout facilities. I prefer not to drill another through-hull and install a pump. I'm trying to find a way to pump out while off shore, directly from the deck fitting. Any suggestions? i found something made by LeeSan in the UK but it is very expensive, even before shipping.
There was an interesting article in the latest Practical Sailor about composting toilets but we had bad experiences with one all last summer on an island in Maine.
Tim
 

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Do you have the ability to direct discharge from your toilet? If not, that would be an important upgrade for sailing in areas with no discharge regulations (like off-shore). It's far preferable and simpler to pump directly out rather than through the holding tank.
 

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Pumpout

No, I don't have direct pumpout from the head. I'm not planning any big passages anyway and I do not want to foul the place where I sleep--so to speak--regardless of regulations.
BTW your Pacific Seacraft is one of my favorite boats. If I hadn't bought a catamaran I would've gotten a PS.
T
 

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No, I don't have direct pumpout from the head. I'm not planning any big passages anyway and I do not want to foul the place where I sleep--so to speak--regardless of regulations.
BTW your Pacific Seacraft is one of my favorite boats. If I hadn't bought a catamaran I would've gotten a PS.
T
Hey , thanks for the boat compliment.:)

As for the discharge -- I think your best bet will be to bite the bullet and add another thru-hull for direct discharge from the toilet while off-shore. You can also add a y-valve that will alternatively send the toilet offal to the holding tank directly. You can then plumb a pump-out hose at the bottom of the holding tank, connect it to an electric or manual macerator pump, then to the new thru-hull for discharge.

I guess I'm just not keen on trying to pump out the holding tank through the deck fitting while sailing off-shore. You could end-up in a real pinch if conditions were too rough to do that (assuming you can find a feasible way), and then you are dealing with an unusable toilet and bursting holding tank while simultaneously coping with heavy weather. Not a pleasant combination!;)
 

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Tim,
hate to say it but the through hull fittings are basically your only choice. Creating a system where you literally suck it out through the deck fitting sounds easy until it breaks at sea, or you have 3 feet of green water on deck for 3 days before it finally rips your improvised fitting off and sinks you and the boat in a pool of poo.
Since you have to do it anyway, do it right and have a direct overboard fitting put in with a y valve that makes it selectable to pump to the tank or overboard, and another valve that allows you to gravity drain your holding tank via the direct overboard through hull. It's just one hole and, two valves and some hose - but DO NOT stint on the quality of the hose it has to be sanity (impermeable) rated, and rigid so you can pump it/create a suction without collapse. Should not run more than 300 bucks or so and you can do most of it yourself.
 

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Telstar 28
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I think it is a better idea to plumb the head directly into the holding tank, and then plumb the pump out hose of the holding tank to a diverter valve, with one leg going up to the deck fitting and the other going to the seacock and through hull, using a diaphragm pump or macerator pump to allow you to dump the holding tank overboard.

This setup minimizes the amount of plumbing and the complexity of the head as much as possible, while giving you the most flexibility overall. Yes, you lose the ability to directly pump the head overboard, but any place you could dump the head directly overboard, you would be able to pump out the holding tank, so no real loss of utility. Also, this allows you to keep the large seacock for the head system closed most of the time, minimizing any risk of the head back siphoning and such.
 

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My boat came with a diaphragm pump that tees off the deck pump out and tees into the sink drain. I know it sounds gross.. but... There is a ball valve directly under the sink. If I close that, pump the tank out through the sink drain thru-hull, and then flush lots of water through it isn't bad at all. Then close the holding tank suction valve, slowly vent the valve under the sink and its all done.. whew... This was very useful cruising through Canadian inside passage where there is NO pumpout facilities anywhere. I don't like the overboard option at anchorages either. I tried to wait for the open water sections before I pumped...

Here is what the system looks like:

I added the valve downstream of the pump so I can lock it shut for legal purposes. The waterline is about right at the top of the holding tank relative to everything in the diagram. From the toilet I can also pump directly overboard via a two-way valve, or pump to the tank where I then get the choice of pumpout at the dock or pump overboard at sea. The normal positions of the valves are shut and shot for the red ones, open for the blue. I can pour water or RV antifreeze into the deck fill to clean out the pump.
Note that the user MUST do the steps properly. Notice that if you don't shut the valve under the galley sink and start pumping there is a very good chance you will fill the sink with poo and pee... this is a very important step to take :)
After pumping you must shut the holding tank suction and pump discharge or risk filling the holding tank with seawater that leaks by the flapper valves in the pump. While this wouldn't sink the boat it is still a very important observation to make.
I have my suspicions that this isn't going to be "approved" by some sailnetters. All I can say is I didn't do it. Wouldn't have done it, but its there and it works... so...
 

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Wharfinger
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Gag reflex

I've pumped out a holding tank, by hand, through the deck fitting, once. It was memorable but not enjoyable. I've seen a couple on another boat take turns doing it between gagging. The big question is; What do you do with the fittings, pump and hoses after you're finished? They would not be welcome anywhere on my boat after they were used once.

My current boat's head discharges directly to a 40 gallon holding tank. From the tank there is a Y-valve which selects between the deck fitting or, via a hand pump, to a thru hull. The thru hull is about 18" below the waterline.

My old boat's head discharged directly overboard, with the thru hull about six inches above the water line. This had less risk of flooding, but attracted frowns whenever the head was used in a quiet anchorage. Suprisingly, it always washed clean and I never saw any stains or residue on the white hull below the thru hull. An above waterline thru hull could be an option if you don't want another hole below the waterline.
 

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I've plumbed my last two boats with the same set up, recommended to me by Ocean Link, based in Rhode Island. The head goes straight to the holding tank, no Y valves. The tank has one discharge line to the deck fitting, one discharge line to a pump for overboard discharge. This system works great, no extra parts to fail. The other beauty of this system is the tank design. All hoses enter the top of the tank and are connected to PVC pipe that internally goes to the bottom - they call them dip tubes. This prevents sewage from standing in the hose - a major source of bad odor.

Good luck.

Skywalker
 

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Baybilly
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Second dog's idea.

I have the same setup as he does with an Edson diaphragm pump that will clear the shyte from a thirty gallon holding tank in about a minute. The exhaust from the tank goes to a Jabsco lockable Y-valve that directs the flow to the deck fitting or over to the pump. I've installed a check valve between the Y and the pump to help with the priming. It's worked perfectly for the past six years.
 

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I installed a tee in the pump out hose between my holding tank and the on deck pump out port. Then I put a good diaphram pump between that tee and a new thru hull with no Y valves anywhere. No second holding tank pump out hose. The thru hull is closed unless pumping overboard and with a closed thru hull, the shore based pump out works fine too. I think an antisyphon loop is important.
 

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Telstar 28
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I installed a tee in the pump out hose between my holding tank and the on deck pump out port. Then I put a good diaphram pump between that tee and a new thru hull with no Y valves anywhere. No second holding tank pump out hose. The thru hull is closed unless pumping overboard and with a closed thru hull, the shore based pump out works fine too. I think an antisyphon loop is important.
Don't believe an anti-siphon loop is necessary, since the vented holding tank should act as a siphon break.
 

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Discussion Starter #14
pumpout

I LIKE it, Scosch! Simple. What kind of pump do you use? And is the thru hull above or below the waterline? Call me crazy but I subscribe to the Pardy's paranoia about thru hulls.
 

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I LIKE it, Scosch! Simple. What kind of pump do you use? And is the thru hull above or below the waterline? Call me crazy but I subscribe to the Pardy's paranoia about thru hulls.
Here is a little trick. Put the thruhull just under the normal waterline, maybe about 1-2" That way it is hidden from normal view, but there are no embarrassing streaks running down the side of the boat... The way mine is positioned I can actually change the ball valve with the boat floating in her slip :) Kind neat to look down into the mushroom and see water just sitting there. But only do that on a CALM day!
 

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I believe it was a "Domestic" (probably imported, ha) Sanipump, diaphram type, from WM. WM also carries a Whale pump with similar specs. The important factor was that it was made (so they say) for waste and wouldnt burn out if run dry accidentally. I originally considered a macerator type pump but they have a reputation for burning up when run dry and although cheaper, one replacement would nullify any savings. I figured by the time the waste had traveled thru all the hoses, the holding tank and the pump that it would be almost "macerated" anyway.
Yes the thru hull is below the water line, but not much. Seems like it belongs below the water line for reasons mentioned. Im not frightened of correctly installed thru hulls.
And Im not convinced that you dont need a siphon loop between the tank and thru hull but it may depend on your installation. Seems to me like the holding tank vent is not in the correct place to solve the problem and is not anymore useful than an open container would be in stopping siphon action. I defer to greater experience but I would think that part through.
 

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The only thing that the anti-siphon loop would do (if between the holding tank and the through hull) would stop the holding tank from back-filling with water. The holding tank would be pumped out only periodically anyway. When not actually pumping it out you would close the seacock and would have to for the deck pumpout to have suction.
 

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The only thing that the anti-siphon loop would do (if between the holding tank and the through hull) would stop the holding tank from back-filling with water. The holding tank would be pumped out only periodically anyway. When not actually pumping it out you would close the seacock and would have to for the deck pumpout to have suction.
Some heads are below sea level at certain angles of heel. If there was a failure in both the flapper valves in the pump and in the head all at the same time it is conceivable you could flood your head... But since you would be sailing at the time hopefully someone would notice! I don't know any setup where a seawater flushed toilet is mounted below normal sealevel, even on Navy ships. That just seems like an entirely bad idea.
 

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Hi Tim
We went to the Bahamas with a Tartan 27 and the holding tank only held 12 gals.We used a gusher pump with a very long hose on the discharge end(Could double up if sinking and reach the cabin with swapped ends and still pump while sailing) and a fitting that fitted the deck outlet.This we used when in deep water or only on a strong ebb tide in an anchorage. The hose was then rinsed by pumping sea water through it ,no problem and cheap.Ellinor from Keldee
 

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Siphoning would depend on the dip tubes. the only way water could bypass the vented tank would be to siphon though the inlet and out the through hull. The holding tank inlet would have to be below the level of liquid in the tank for this to be possible, but it would go in and straight out. System would be no different than the sink drain, filling to whatever the waterline is.
It might even do a little flushing.......
 
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