Very Basic Marine Toilet Questions

[peghall]

Has anyone installed VacuFlush MSD (or similar products) which claim (at a cost I expect) to reduce waste water volume by 3 litres per flush (from 3.781 to .76) (Holding Tank Efficiency Data).

SeaLand's claim that the V/Flush can use "as little as" 1 pint of flush water is VERY carefully worded. If only urine is flushed...no water added to the bowl first, no TP either...then yes, you CAN get away with that little, at least for a few flushes. But if you do much of that, unless you want odor, at least once a day you need to run at least half a bowl of clean water through it to rinse out the system. It's also advisable to add at least half a bowl of water ahead of solids or any TP (iow, every time a female uses the toilet)...that's a quart or more. It's also essential to leave the pedal down for at least 7-10 seconds after the bowl is empty to rinse out the pump and duckbills--to prevent a buildup in the pump or bits of waste or TP from becoming stuck in a duckbill, creating one of those pesky air leaks that causes the pump to cycle for no reason...at least another quart. And if you don't want permeated hoses, it's a very good idea--last thing before the boat will sit (or at least once a week if you're living aboard)--to fill the bowl to the rim with clean water and flush it through to thoroughly rinse out the vacuum tank, hoses and pump...'cuz suction splatters waste all over 'em and the flush water flow isn't sufficient to completely fill the hoses. So, averaged out over a week, the VacuFlush actually NEEDS about the same amount of flush water as most other toilets that use pressurized flush water: about .5 gal. If you already have a VacuFlush and you're using much less than that, you're asking for problems.

Btw...I had V/Flush toilets on my last two boats and was also a dealer for nearly 10 years...so I'm INTIMATELY acquainted with 'em...what keeps 'em working trouble-free and what doesn't.

Also what comments are there in regard to composting toilets. My main concern is capacity, because once they are full, there isn't anything one can do.

Composting is a terrific concept, but IMHO, it's not quite there for onboard use yet. "Nature's Head" seems to be very similar to the AirHead..Air Head Dry Toilet: Marine Composting Toilets - Environmentally Friendly Marine Composting Toilet System Neither of which is a true composter but a dessicator. The main drawbacks to onboard composters and dessicators are:

1. What to do with excess liquids. 90% of human waste IS liquid...mostly urine, but even solids are at least 75% liquid. Excess liquids have to be drained off , or you have wet soggy organic material...and wet soggy material doesn't compost, it rots. Adding dry material--peat moss is the recommended material 'cuz it breaks down quickly--regularly helps some, and there's usually more liquids than the evaporator--which, btw, requires power--in the self-contained units can handle either. Both the AirHead and Nature's Head separate urine from solid waste the urine is directed into in jugs (or a tank). You can't legally drain 'em overboard (unless you're at sea beyond the 3 mile limit), so the jugs must be stored and carried off the boat or the tank must be pumped out same as any other tank. So I can't see much advantage to this over a portapotty.

2. Even though urine is collected separately, solid waste is 75% liquid, so peat moss is needed to keep it dry. Enough peat moss to keep the thing working during an extended cruise can take up more storage space than a holding tank.

3. Composters need a 3" vent stack... AirHead originally specified a 3 vent but is now claiming that a 1.5 vent is adequate.

4. Continuous power 24/7 to run the evaporator.

5. Composting only works in temperatures above 70 F....and only works really well above 75. Below 70, bacterial activity becomes increasingly sluggish--TOO sluggish to make anything happen. So you have to keep it warm all winter--that's 24/7--or waste will just sit there. The good news is, nothing stinks much in cold weather either.

You may decide that this thing is greatest idea since the pop up toaster...but IMO, unless you're in inland "no discharge" waters, a Type I MSD (ElectroScan or PuraSan) is a MUCH better solution for the same money.

[lorenzo123]

Add a little salad oil once in a while to keep the pump lubricated; also, I stopped using seawater to flush. I either pour fresh water in or use the shower flex hose head. The salt water kills the bacteria growing in the tank and causes the smell. Since switching, little to no smell. Welcome.

[peghall]

Originally Posted by DaveOnCudjoe

The best system I ever had was a Mansfield TDX now sold as Dometic711-M28.Dave

The TDX was a treatment device (and a gawdawful one too!), not a toilet. You're confusing it with the original Mansfield 911-M28 "Marine Traveler." It hasn't changed a bit. Dometic Sanitation Systems And you're right...it's a great system! However, it only held/holds 9 gallons, not 10.

[peghall]

You might also consider replacing the joker valve in your toilet discharge. When it becomes worn, the "lips" no longer close, allowing any gasses in the system to escape into the bowl. Joker valves should be replaced at least every two years...annually if you live aboard.

[peghall]

Originally Posted by lorenzo123

Add a little salad oil once in a while to keep the pump lubricated; also, I stopped using seawater to flush. I either pour fresh water in or use the shower flex hose head. The salt water kills the bacteria growing in the tank and causes the smell. Since switching, little to no smell. Welcome.

Anything thin enough to be poured into the bowl is also so thin that it just washes out in a few flushes...so it's a never ending job! There's a much easier way:

Every new toilet leaves the factory slathered in a thick Teflon grease that keeps the pump lubricated for at least a year, sometimes even longer. It's a 10 minute job to open up the pump and give it a good healthy squirt of the grease...pump a few times to spread it all over the inside of the cylinder...close up the pump again...you're done for another year.

Just pouring water into the bowl to flush is not good for the pump, because what's in the bowl only goes through the bottom part of the pump...the rest of pump stays dry, which puts excess wear on the seals and o-rings. Again, there's a simpler way that works on most sailboats: tee the head intake line into the head sink drain line just ahead of the thru-hull. Use sea water to flush...but when closing up the boat, after you've closed all the seacocks (you DO close the seacocks when leaving the boat???) fill the sink with clean fresh water...flush the toilet. The toilet will pull the water out of the sink, rinsing all the sea water out of the intake line, pump, channel in the rim of the bowl AND the discharge line. No more stinky sea water when you come back.

[S/V Alchemy]

I am in the Great Lakes, but I set up my sink drain in line (via two shut offs and a T fitting) to be diverted into my old ITT Brydon head. It not only clears out the critter habitat, but I can follow it with whatever I'm using to winterize the plumbing.

[boden36]

If you have an old Jabsco or similar manual toilet, consider removing the pump completely and replacing it with an adaptor for hose (surprisingly easy to do with a home made adaptor plate) and then directing the hose to a hand operated diaphragm pump ( We use a Whale). For the flush, use a smaller hand operated diaphragm pump.
We have used this system for 25 yrs and it has been 100% reliable. We carry spare pumps but have only needed to change pumps once and even then it was optional.
For guests, it is simple; one pump in, the other out. No valves or complications.
Additionally, with a Y valve it doubles as an emergency bilge pump.
Regards,
Richard.

[lorenzo123]

Perhaps we're talking about different pumpt. I have a Jabsco hand pump head. The salad oil (or any vegetable oil) idea has been floating around for some time and recently described and recommeded by Latitude 38 (SF Bay Area). I've followed it for years with no regrets. And have utilized it on head pumps that were beginning to get a little squeaky. I also put a little on the pump rod once in awhile. I would think any oil with a little viscosity would cling a little bit, and, having kicked this around with a few friends, the consensus was that anything thicker wouldn't be good.

My point about about not using seawater at all allows the little critters growing in head tank to continue, therefore there's no stench from their carcasses.

But

[peghall]

We're talking about the same pump...and yes, people have been pouring oil into every make/model of manual toilet every few weeks for decades. There are a lot of things people have been doing for decades because it's never occurred to 'em that there could be an easier, cheaper and better way to do it.

Keeping a manual toilet lubricated by pouring oil into it is a never ending job and actually rather expensive when you consider how much oil you need per year....REALLY expensive if you use liquid "head lube." But there's an easier way that takes only about 10 minutes once a year. Remove the top from your Jabsco pump--6 screws or 1 hex nut, depending on the age of the toilet....stick the nozzle of a $4.95 tube of Teflon grease into the pump and squeeze out about a tablespoon...replace the top...pump a few times to spread it all over the inside of the pump cylinder...you're done till next year. And, unlike Mazola, that same teflon grease can be used to lube seacocks, manual diaphragm pumps, y-valves and anything else that stays wet...that tube will also last for years! If you do this as PREVENTIVE maintenance instead of waiting till the pump starts to squeak and gets stiff (which is an indicator of friction), the seals and o-rings will last twice as long.

I have no idea what you mean by "not using sea water allows the little critters growing the tank to continue..." Sea water is FULL of critters! However, critter carcasses only stink in anaerobic (without oxygen) conditions. There's so much bacteria in sewage that the critters don't even notice whether the toilet uses sea water or fresh...as long as the tank is sufficiently well ventilated to keep it aerobic, they won't stink. So the only reason to use fresh is to prevent INTAKE odor. However, my point wasn't WHETHER to use fresh water, it was HOW you're using it...Pouring down the toilet instead of using the pump to pull it in is damaging to the pump. There's a better way to do it, which I described above.

[lorenzo123]

RE: bidets, check Latitude 38, Letters section, November 2010 (Latitude 38 Letters - November 2010).

[graydog]

I love the lavac for another reason. You can add another y-valve to allow the pump to take bilge water and discharge it overboard via the thruhull

[lorenzo123]

RE: vegetable oil in head; Greatly appreciate the expertise. However, have to disagree on the expense of oil poured into a head. Had a Jabsco in my Ericson 29 for 9 years; it functioned without fail the entire time. Poured about three or four tablespoons of veggie oil in, plus ran a dab on the pump handle shaft. Probably spent about 50 cents a year. Point taken about waiting for head to squeak. PM is better than waiting for symptoms. I only mentioned it anecdotally, as many of us haven't made a career out of boating, and therefore a few shortcuts do sometimes venture into the routines in our lives, not all of them detrimental. BTW, I also use white vinegar to clean.

Perhaps the more important consideration, however, is the use of Teflon. While effective it, like all things, eventually ends up in the greater environment (beyond the boat) and does not break down easily. It can also be carcinogenic. That 5 dollar tube of Teflon lube eventually has a very high cost.

RE: seawater in the tank vs. freshwater. The theory is that salt water kills the organisms that live in what we excrete (which is what goes into the tank). If they die, they they rot and then they smell. Also, my experience, while limited, indicates that dead things smell in aerobic environments. True, lots of critters are in seawater water too, but they are the one that we have inside us. Again, only my personal experience (and that of some locals who passed on the tip to me for ten or so years. Stopped using seawater, smell went away.