Porta-potties & pump-out stations

Mar 2, 2018
232
Catalina Wing Keel San Diego
Does anyone have any experience using a pump=out station to empty their porta-potty?
 

AaronD

.
Aug 10, 2014
723
Catalina 22 9874 Newberg, OR / Olympia, WA
A few times; the station at our marina, and the other one or two I've used have a spot to dump your porta-potty. You turn on the pump, dump into the trough, and rinse with the water hose. It's a little gross; wear gloves and don't bend over too close :yikes:. Plumbing the MSD pump-out was a big improvement. But you can make it work.

I'm not sure whether all pump-outs have that dump spot, or if their presence/absence is labeled consistently in ActiveCaptain or other sources of dump locations - if not, you'll want to figure out which do in your area, and make your plans accordingly.
 
Dec 2, 1997
8,708
- - LIttle Rock
Plumbing the MSD pump-out was a big improvement.
If you don't know what he means by that, an "MSD" portapotty has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you can pump it out instead of having carry anything off the boat to empty it.
A 5-6 gallon model (which has the same footprint as your portable) holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $200--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

Check out the Thetford 550P MSD and the Dometic/SeaLand 975MSD Sanipottie. Thetford has discontinued the 550PMSD (and hasn't replaced it with another MSD version), but it’s still available from most retailers…the Dometic 975MSD is still in production. They’re comparable, and not much can go wrong with either one...so if you like the Thetford, find out if sbo.com still carries it before shopping for it elsewhere. Sbo.com does have the Dometic 975MSD.

--Peggie
 

AaronD

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Aug 10, 2014
723
Catalina 22 9874 Newberg, OR / Olympia, WA
Thanks for elaborating, @Peggie Hall HeadMistress (and for others, always listen to her - she knows this stuff better than anyone). My post on the MSD project is at https://forums.sailboatowners.com/i...and-restoring-9874.195739/page-2#post-1523072, and there's discussion from others and a parts list in later posts on that thread.

Measure the space available under your V-berth carefully before buying - the available units differ very slightly in height, and for some people it's been just enough to make the difference between fitting / not fitting their V-berth boards in place. Presumably you could cut out the floor / liner and rebuild it lower to drop the MSD just a bit. But that turns a medium-sized project into a much larger one (and weakens the liner if you aren't careful about it).
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Aaron and Peggy thank you so much. Arron I took a look at your install and it looks great! Doesn't seem to be to difficult . Doesn't look like it would be to easy to dump at sea though. This is deffinatly worth investigating farther.
 
Dec 2, 1997
8,708
- - LIttle Rock
the available units differ very slightly in height, and for some people it's been just enough to make the difference between fitting / not fitting their V-berth boards in place.
There's actually a pretty easy solution for that: remove the lid and let the cushion be the cover. The "trapdoor" in the bowl seals the tank, so no worry about splashing. Just make sure the bowl is rinsed clean after use. (easier if you remember to add a little water ahead of solids).
--Peggie
 
Dec 2, 1997
8,708
- - LIttle Rock
Doesn't look like it would be to easy to dump at sea though. This is deffinatly worth investigating farther.
A bit more of a challenge than you'd want to deal with unless you want to install a thru-hull (which doesn't HAVE to be below-waterline). Once you have that, a y-valve, a little more hose and either a macerator pump or a manual diaphragm pump are all you'd need. But the real question is, how often would you need to use it? You'd have to be in open ocean at least 3 miles from the nearest point on whole US coastline to do so legally... and also keep in mind that that a 5.5 gal MSD portapotty uses so little flush water--just enough to rinse the bowl--that it holds 50-60 flushes, which can easily last two people a entire 3 day weekend. The lee rail can extend the time between pumpouts too.
--Peggie
 
Oct 10, 2013
127
Catalina 22 Minneapolis
My Dometic 975MSD should be arriving this afternoon. I'll be able to report back how well it fits in the v-berth. (I never put the boards in, so I'm not worried if it's a little tall.)
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Minnie sail can you post a photo of what the back of the 975 where the hoses or fitting come looks like please.
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Hi Peggie !
Thanks for post that.
I have looked over instruction manuel and see # 11 and 12 but never found any "Installation" notes for 11/12. Just the drawing. Am I missing something here. So I'm known to be dense sometimes.It looks as if 11/12 simply go into where #6 go's but I'm assuming that. AronD's installation photo has the hoses coming out the bottom in the back.
I'm thinking if I can add the MSD feature to the tank I could possible be able to simply take the holding take out at a pump out a do the deed there. There by not having to drill any holes in the boat.
I'm gonna call them and ask.
Thanks for the help!
 
Dec 2, 1997
8,708
- - LIttle Rock
I'm thinking if I can add the MSD feature to the tank I could possible be able to simply take the holding take out at a pump out a do the deed there
The MSD feature includes a fitting for a vent line and a pumpout line that make it unnecessary to take the tank off the boat...so why bother to install the fittings if you don't want to install the plumbing to use 'em?
--Peggie
 
Last edited:
Dec 2, 1997
8,708
- - LIttle Rock
AronD's installation photo has the hoses coming out the bottom in the back.
No, it doesn't. It's a view of the potty straight down from above it...the hoses are coming off the tank at the TOP of it which does put 'em below the bowl, but there's no way a vent fitting could be at the bottom of a tank!
--Peggie
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Ok it makes sense now.
#6 is replace by #11 or #12
The elbow existing the top back is turned sideways in Aron's photo and heads to the deck clean out
White line out is the vent (guessing)
Blue line ???
It looks like I could install #11 or #12 with a pomp out fitting and be able to take the hold tank a pump out station.
Or better yet
Try and make a pump out fitting that screws to my existing porta tank. That could be a really cheap and easy fix
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Peggie, Just looking into all my options at the moment before I spend any money. I have a perfectly good porta already so why not ry and see if I can use it first.
 
Dec 2, 1997
8,708
- - LIttle Rock
You prob'ly have the small 2-3 gallon version...the 5.5 gallon version holds a LOT more flushes--50-60 compared to 20-25. Both sizes have the same footprint and the price difference is very small. So you could go a lot longer between pumpouts, But a full 5.5 gal tank weighs close to 50 lbs, which would be waaay more than anyone wants to carry off the boat. You might want to add all that into the mix as you weigh your options.
--Peggie
 
Mar 2, 2018
232
Catalina Wing Keel San Diego
Thanks Peggie,
We normally are out for now longer than 5 days at a time. If we are doing a channel crossing we can dump in the middle 10 miles out. If I'm staying close to the coast or in a harbor it would be nice to use the pump out so my small tank would be fine. I just need to figure out something that would fit the tank pipe and the pump out pipe. Interesting project.

Thanks for all the help and I've got a case of Beer with your name on it!