Using household plumbing on a boat

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swampu

Guru
Commercial Member
Joined
Jul 25, 2011
Messages
1,384
Location
USA
Vessel Name
Cajun Rose
Vessel Make
Biloxi Lugger
Well, about the plumb the Rose. Besides the actual pump for pressurizing the tank water and the water heater, can I use household valves and toilets? Pex for water lines and pvc for drain lines? I would isolate for example where the sink would meet the thruhull with a piece of drain hose but for the most part I would like to use ridged pipe.
Any thoughts?
:hide:
 
I am thinking of using household toilets. My toilets will be above the waterline and directly above the holding tanks. So I think all I have to worry about is water in the tank and bowl sloshing out. Two ideas: "flush valve" ("Sloan" valve?, I've forgotten) toilets (commercial type) with no tank, or "Flushmate" type, with a pressure vessel in the tank so no sloshing there. But what about the bowl?
 
100% on the PEX. Great stuff for boats.

I'd use PVC sparingly. I suspect vibrations and flexing of the hull would be a problem.

Household toilets don't seem like a good option. They expect a 3" or 4" gravity drain, pressurized potable water and typically use a lot of water. Also, having an open tank full of water sloshing around doesn't sound ideal.
 
For the toilets, if you have a straight drop to the holding tank, RV toilets are the best choice. Simple mechanism, easy to install and maintain.

Bill
 
For the toilets, if you have a straight drop to the holding tank, RV toilets are the best choice. Simple mechanism, easy to install and maintain.

Bill

The RV toilets I have looked at have two concerns: as they don't hold any water in the bowl, odors from the tank can escape, and as they don't hold any water, many come with a spray nozzle to clean the bowl after use. Don't care for that.
 
Household toilets don't seem like a good option. They expect a 3" or 4" gravity drain, pressurized potable water and typically use a lot of water. Also, having an open tank full of water sloshing around doesn't sound ideal.

The flow path through most household toilets is 2", and some are up to 2-3/8". Marine toilets are usually 1-3/4", which may contribute to clogging problems.

Flushmate toilets use one gallon per full flush (I don't know if any offer a reduced flush for No. 1s). Marine toilets offer reduced water usage options, but this also contributes to clogs. I don't think one gallon per full flush is far off marine toilet full flushes.
 
PVC works just fine in boats. It handles the vibration and minor boat flexing perfectly well. any place you use it it must have adequate "fall" If at any time the boat is stored in freezing weather and the lines are full of water, the PVC will shatter. It is an excellent choice in waste lines because it is impermeable.

Using a household toilet will not work. It uses too much water for one thing. Water will slosh out of the water closet and the water closet itself is likely to leak because it is not designed to handle the accelerations of a boat moving over waves.
 
The Dometic toilet in my RV has no separate flush wand. It flushes nicely with a ring of water injected below the rim. It lets you use a pint or so to flush #1 and as much as you need for #2. It has a secure ball valve at the bottom that blocks any odors. It does need to be mounted so it is a straight shot downward to the holding tank and it may be a problem when bouncing around in a seaway with an almost full tank.


I think PVC is fine for drains, but I would try to only use it above the water line and transition to hose when it is necessary to go lower in the bilge. It is subject to cracking under vibration and below the water line could be a disaster.


PEX is fine for fresh water plumbing- either with the screw on compression type fittings or the mechanical clamp ones.


David
 
Using a household toilet will not work. Water will slosh out of the water closet and the water closet itself is likely to leak because it is not designed to handle the accelerations of a boat moving over waves.

See this:

http://www.flushmate.com/models/pdf/koohoo-T-3052C.pdf

Sorry for the Non-english, it was the only image of a one-piece I could find that shows the tank inside the "water closet." Apparently the tank fills from the bottom, trapping and compressing air above, which then "powers" the flush.
 
Well, about the plumb the Rose. Besides the actual pump for pressurizing the tank water and the water heater, can I use household valves and toilets?

Not a good idea, not only for the reasons already posted, but because a) household toilets rely on a siphon started by releasing enough water from the reservoir (which has to fed with pressurized fresh water from your potable water supply or by a pump to bring in sea water) and gravity to get it to the sewer line, and...b) marine toilets are designed to PUSH bowl contents to their destination (tank, overboard, treatment device). You COULD use hard PVC for any long straight lines, but PEX and other fresh water plumbing isn't rated for sanitation or below-waterline use.

The flow path through most household toilets is 2", and some are up to 2-3/8". Marine toilets are usually 1-3/4", which may contribute to clogging problems.

1.5" ID is the standard size for discharge hoses on marine toilets.

Flushmate toilets use one gallon per full flush (I don't know if any offer a reduced flush for No. 1s). Marine toilets offer reduced water usage options, but this also contributes to clogs. I don't think one gallon per full flush is far off marine toilet full flushes.

Today's manual and electric marine toilets only need about .5 gal water/flush and when installed, operated and maintained according to mfr's instructions, rarely clog. 99% of clogs are caused by guests...the remaining 1% are caused by owners who don't maintain the system.

The RV toilets I have looked at have two concerns: as they don't hold any water in the bowl, odors from the tank can escape, and as they don't hold any water, many come with a spray nozzle to clean the bowl after use. Don't care for that.

Dometic/SeaLand RV toilets have flush mechanisms identical to their VacuFlush toilets...step on a pedal to open a trap door in the bottom of the bowl and start flush water running, lift the pedal to add water to the bowl ahead of use.

If you'd like some help designing a trouble-free ODOR free marine sanitation system, give me a shout. Meanwhile, you might find some worthwhile information here: http://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/
 
Pex is great for fresh water systems.

Pretty sure Sea Ray uses it and is OK with the NMMA. They use blue and red tubing and fittings for PEX so I can't imagine it's not.

As posted, many RV toilets are not open to the holding or flush system. I have one in my master, has worked flawlessly for 4 years with a macerator replacement because of a pebble in the rock salt. Can use any type macerator because it is down in the engine room and very quiet.
 
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Pex is great for fresh water systems.

But ONLY for fresh water, not for sanitation, with the possible exception of the line connecting a toilet designed to use pressurized flush water to the fresh water plumbing...and I'm not sure it's even used for that. SeaRay used sanitation hose to connect the VacuFlush on my '85 340 to the cold water line in the head.
 
"The RV toilets I have looked at have two concerns: as they don't hold any water in the bowl, odors from the tank can escape,"

Perhaps if they are worn out , the usual lack of seal I see is folks closing the foot too early valve on paper , which then keeps the ball from sealing.

To not stink RV use the same under sink J traps as would be found in every dirt house.

With a std seal in the toilet , water IS held for no smell.

The RV head must be filled with water after installation so the overflow hole in its construction gets flooded.

The tubing behind this is S shaped and works as a J trap would to stop odors.

A Wand for an RV unit is so slide streaks can be powered off , rather than simply flushing till there gone.

The best trick for lowest water use is Pam sprayed inside the unit , and using the fill valve just enough to wet the bowl surface first..

Most RV have room for a 1 1/2 vent pipe thru the roof to service the waste tank, so most get loads of air and dont stink.

At 1 1/2 or 2 gals per flush the house toilet will fill the holding tank and empty the water tank at 10X or 20X the RV rate.

40gal holding tank or 500gal, you chose.

In houses plastic tubing works because the common water use is 100g a day.

This plus local water supply chlorine keeps the pipes fresh.

In a boat that might sit for weeks or months copper tubing will not allow "stuff" to grow.seems to work best.

Sadly 5/8 flair fittings are not cheap, but with a flair tool and tubing cutter any part of the system can be replaced worldwide. NO torch required.

5/8 is used so the FW pump can be tuned back to lower the pressure to save electric and still give a great shower.Big boats with washing machines and dishwashers usually don't bother.
 
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Potable Water Systems | | PassageMaker



http://www.passagemaker.com/channels/avoiding-sanitation-system-woes/


The greatest challenge for a sanitation system hose involves standing effluent. It’s not a pretty visualization, but bear with me. When these hoses are installed in such a way as to create large dips, low spots, or U-shaped bends, effluent will settle in these areas making life difficult for even the most permeation-resistant hoses, as well as increasing the likelihood of clogging. The best course of action involves eliminating such dips, and barring this, replacing them with sections of rigid PVC sanitation pipe.
A frequent location for such a scenario is at a holding tank whose fittings are located on the bottom or lower side of the tank (an undesirable design trait). Hoses attached to such fittings are continuously submerged in effluent, making permeation a veritable certainty. In this case, the solutions are: relocation of the fittings to the top of the tank and using a drop or dip tube, installation of rigid PVC or fiberglass tubing in place of the hose where it will be submerged, or replacement of the tank with one that does not rely on bottom fittings.
 
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Well, about the plumb the Rose. Besides the actual pump for pressurizing the tank water and the water heater, can I use household valves and toilets?

Not a good idea, not only for the reasons already posted, but because a) household toilets rely on a siphon started by releasing enough water from the reservoir (which has to fed with pressurized fresh water from your potable water supply or by a pump to bring in sea water) and gravity to get it to the sewer line, and...b) marine toilets are designed to PUSH bowl contents to their destination (tank, overboard, treatment device). You COULD use hard PVC for any long straight lines, but PEX and other fresh water plumbing isn't rated for sanitation or below-waterline use.

The flow path through most household toilets is 2", and some are up to 2-3/8". Marine toilets are usually 1-3/4", which may contribute to clogging problems.

1.5" ID is the standard size for discharge hoses on marine toilets.

Flushmate toilets use one gallon per full flush (I don't know if any offer a reduced flush for No. 1s). Marine toilets offer reduced water usage options, but this also contributes to clogs. I don't think one gallon per full flush is far off marine toilet full flushes.

Today's manual and electric marine toilets only need about .5 gal water/flush and when installed, operated and maintained according to mfr's instructions, rarely clog. 99% of clogs are caused by guests...the remaining 1% are caused by owners who don't maintain the system.

The RV toilets I have looked at have two concerns: as they don't hold any water in the bowl, odors from the tank can escape, and as they don't hold any water, many come with a spray nozzle to clean the bowl after use. Don't care for that.

Dometic/SeaLand RV toilets have flush mechanisms identical to their VacuFlush toilets...step on a pedal to open a trap door in the bottom of the bowl and start flush water running, lift the pedal to add water to the bowl ahead of use.

If you'd like some help designing a trouble-free ODOR free marine sanitation system, give me a shout. Meanwhile, you might find some worthwhile information here: http://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/

I bought Peggy's book some time ago (just before the new version, dang it), and I listen carefully to everything she says.

Having said that, household toilets are about the most reliable, trouble-free appliances in my life. From everything I read, marine toilets, not so much. And if the problems are due to guests or owner incompetence, well, I can expect both.
 
PEX is great for the fresh water system. I like Sea Tech fittings because they are so fast and easy to install. Just shove the PEX in and you're done. No tools needed. You can also remove and reuse them easily.

Follow Peggie's recommendations on designing your black water system.
 
Whizzit that so many people have over-complicate simple projects???

The greatest challenge for a sanitation system hose involves standing effluent...when these hoses are installed in such a way as to create large dips, low spots, or U-shaped bends, effluent will settle in these areas making life difficult for even the most permeation-resistant hoses, as well as increasing the likelihood of clogging. The best course of action involves eliminating such dips, and barring this, replacing them with sections of rigid PVC sanitation pipe.

Or...just don't leave effluent standing in the hose...replace it by flushing plenty of clean water before the boat will sit.

A frequent location for such a scenario is at a holding tank whose fittings are located on the bottom or lower side of the tank (an undesirable design trait)...
the solutions are: relocation of the fittings to the top of the tank and using a drop or dip tube, installation of rigid PVC or fiberglass tubing in place of the hose where it will be submerged, or replacement of the tank with one that does not rely on bottom fittings.

It's not always possible to put all the fittings on the top of the tank...that requires at least 5" clearance above it. There should only be ONE fitting at the bottom of the tank--the discharge/pumpout line. The simple solution: hard PVC from the fitting to the top of the tank, then switch to hose the rest of the way to the deck pumpout fitting. Any y-valve or tee in that line to an overboard pump can be installed above the hard pipe.

Hey Cottontop...there's no rule preventing you from owning both editions. :) The new one is also available in kindle.
http://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/
 
Paul as large as The Rose is and the potential length involved in waste run I'd use as much pvc pipe as practical owing to the huge price difference alone. It's fun as hell to spend other folks money but until someone can convince me otherwise I see no upside to a hose in place of a pipe.

As to 5" clearance above a tank that's not even a remote consideration on a boat this huge.
 
There shouldn't be a long run from the toilet to the tank....6' is optimal, a couple of feet more only with a lot of help from gravity. If the boat is that big and has multiple toilets it may be necessary to install more than one tank.

edit: I just clicked on the Rose's profile photo...there's no way you should even consider trying to put all her toilets on a single tank.

It's fun as hell to spend other folks money but until someone can convince me otherwise I see no upside to a hose in place of a pipe.

There's a considerable upside to hose in a run that has multiple bends which would require breaking hard pipe to insert inline radius fittings.
 
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How to install a toilet in your house (never actually had to do this, because they are maintenance free and last forever):

1. Buy toilet
2. Put the wax seal down, more or less centered around the hole in the floor.
3. Set the toilet down over the wax seal and the two bolts sticking up out of the floor (all houses come with these bolts sticking up). This is the hardest part of the job, because the toilet is heavy, and you don't like having your face near the toilet, even if it's new.
4. Tighten the bolts.
5. Attach the inlet water line.
6. Open the inlet water line valve.
7. Surf the web for a while, cursing periodically to convince the wife it's a hard job.

How to install a toilet in your boat:

1. Read Peggy's book (It's not a short book) (and I bet the new edition is longer).
2. Spend endless hours learning about different marine toilets (are there "joker valves" on a household toilet? No.) and the problems associated with them, all of which require a plastic suit, goggles, a respirator and ben-gay under your nose (back-up if the respirator leaks) to fix.
3. Design the boat to accomodate household toilets. See number 1, above.
 
Household toilets are great if you have an unlimited water supply and a treatment device...or a huge holding tank. I have neither so I designed a system that works for me and my boat....each boat is a bit different and used differently, so one system doesn't necessarily have to fit all.

What is hard for some or for them to understand isn't necessarily hard for others.
 
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Having said that, household toilets are about the most reliable, trouble-free appliances in my life. From everything I read, marine toilets, not so much.

Not in my experience. I spent way way less time tending to our three Vacuflush systems when we lived aboard full time than I did in similar time spans in several different houses.

There are reasons you don't see household toilets on boats; Peggy lists a few. I suppose if the boat is never going to leave the dock, never be in any sort of seaway whatsoever, you could get away with it.

Beside flushing water and the occasional dose of distilled white vinegar through now and then, permeation can be prevented in a properly installed system by buying good hoses.
 
Not in my experience. I spent way way less time tending to our three Vacuflush systems when we lived aboard full time than I did in similar time spans in several different houses.

There are reasons you don't see household toilets on boats; Peggy lists a few. I suppose if the boat is never going to leave the dock, never be in any sort of seaway whatsoever, you could get away with it.

I am glad to hear that marine toilets are not always a disaster. I am sure good design is key.

I am truly interested in household toilets for the boat. I appreciate that most boats have limited space, electricity, water and payload, requiring some of the clever solutions found in marine toilets.

But the OP's boat is 65'. Mine will be a 50' cat. I will have abundant water and electricity, but have to watch the size of holding tanks. The OP probably has no meaningful restrictions.

So why not household toilets? Too much water use? Modern household toilets are pretty stingy, having reduced flush settings for #1 and only requiring 1 gallon for #2. On a friend's boat, we are admonished to flush "often." I wonder about the water use argument. I do know I'd rather pump out more often than ever don the plastic suit.

Sloshing water? Well, Sloan valve toilets don't have a tank, and Flushmate toilets have a sealed tank. But water in the bowl (necessary to block fumes from the holding tank)? Not sure.

If someone knows the killer objection, I'd love to hear it, so I could quit thinking about this.
 
Well then, why don't you put some in and let us know how it works for you? Somebody has to be a pioneer...
 
You're overlooking something very important: In a house, the toilet--all "appliances"--are JUST an appliance. Power is supplied from external sources, water is supplied from an external source...when you flush a toilet it leaves the house and goes to an external sewer which takes it an external sewage treatment plant. So all you have to do when you install or replace an appliance in a house is connect it to the external utility.

But EVERYTHING on a boat is a component in a system..and anything done (or wasn't done that should have been) to ANY component in any system impacts the entire system. Away from the dock, a boat is totally reliant it's own systems...The boat's electrical systems provide the power...the boat's fresh water system provides all the water. The toilet is a component in a system that may or may not need both, or may use a pump--integral or external--to bring in the water it needs. And toilet waste management is a part of that system.

Household toilets need gravity to work...not always available on a boat. Large ships can use household toilets because they have the equivalent of municipal sewer system and pumps big enough to assist or replace gravity. Theirs are also sanitation "systems"--systems that require a LOT of maintenance.

Marine sanitation systems are actually pretty simple...a toilet that either pulls in flush water or relies on the fresh water system to provide it and has a pump that uses either manual labor or an electric motor to move the bowl contents to its destination. Yes, they need maintenance--a LOT less if it's PREVENTIVE maintenance than is needed to solve the problems which, at least 90% of the time, could have been prevented.

Do household toilet need joker valves? No, but you've obviously never had to replace the flapper valve in the flush water tank. Or the mechanism that lifts and resets it...and then spend half a day adjusting the float that turns the water off before the water overflows the tank, only to find out that the plumbing "expert" at the big box hardware store sold you the wrong type. Or found out that you wouldn't have had to replace the flapper valve if you'd known that the Clorox "puck" sold to go in the tank would destroy it. Wax rings are only good for about 10 years before the toilet starts to leak...a lot less if they dry out from non-use of the toilet for even a few months. And the toilet weighs about 75 lbs...more than I can lift by myself, so I either have hire somebody to do it or recruit someone's able bodies husband to help. And household toilets aren't clog proof either (NEVER try to flush clumping cat litter!)

So tell me again how much simpler and easier household toilets would be on a boat...???
 
We have a Raritan Atlantis A12 that twenty years old and still working after only one minor tuneup in 1998. The main drain/chip and shred pump is starting to warble a little at times but is still pumping but we may be looking at a Rairtan Elegance soon.
Don't you just love that name for a toilet.
 
Well then, why don't you put some in and let us know how it works for you? Somebody has to be a pioneer...

OK, you've forced me to admit to my evil scheme:

I'm trying to encourage the OP to be the pioneer (I actually thought there might already be pioneers, but maybe not). Then (s)he can report. I'm still a few months from building.
 
On my last boat it had a hybrid system, rv direct dump toilet with 1' of pipe to the holding tank and a standard marine electric macerator head in the forward cabin that pushed effluent back to the tank. The direct rv dump unit was bulletproof, the fwd. unit needed typical macerator maintenance. The holding tank had a 1" vent that kept smell at bay. The rv unit was a fresh water flush. In a perfect world I would have the same unit again in a heartbeat.
Hollywood
 
On my last boat it had a hybrid system, rv direct dump toilet with 1' of pipe to the holding tank and a standard marine electric macerator head in the forward cabin that pushed effluent back to the tank. The direct rv dump unit was bulletproof, the fwd. unit needed typical macerator maintenance. The holding tank had a 1" vent that kept smell at bay. The rv unit was a fresh water flush. In a perfect world I would have the same unit again in a heartbeat.
Hollywood

Do you recall the make/model of the RV unit? Peggy has encouraged me in a long-ago posting to consider RV units. I have looked; Not quite household, but maybe that's as good as it gets.

OP, I still want you to go the household route.
 
Do you recall the make/model of the RV unit? Peggy has encouraged me in a long-ago posting to consider RV units. I have looked; Not quite household, but maybe that's as good as it gets.

OP, I still want you to go the household route.

It was a raritan unit, same as the vacuflush in my current boat. No way I would consider a home unit.. Even a power flush.. They need some pretty decent water psi to work.
Hollywood
 
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