Thetford 550p porta potti

Anonymous 121765 · Oct 19, 2015

Gene,
I used to have a C22 with a porta-potty.
Can you attach the site for this showing what the hold-down assy. consists of?

CR

woodster · Oct 19, 2015

look here http://www.thetford.com/wp-content/uploads/2015/03/Owners-Manual-Porta-Potti.pdf it looks like the tank comes out but the main part stays installed there are directions on how to empty it

centerline · Oct 19, 2015

I use a thetford portable in our mac25 and I dont use tie downs... the thing is more stabil than you may think. it has slid around on the floor but never turned on its side. we do have carpet in the head area so that helps hold it in place, but if you are just setting it directly on the fiberglass liner, it will slide around very easy...
the potty is totally enclosed if the valve is shut properly, so even if it were to roll over, it wont spill...
im not suggesting that the tiedowns are unnecessary things, but only saying that in the past 4 years of owning the boat, I havent used any to attach our potty down, and we have trailered long distances and been in some pretty rough water, without any problems.

25yearslater · Oct 19, 2015

I did the exact same thing. The hold down kit is being redesigned since my conversation with them. No problem with the unit itself as it is the same as the MSD. The MSD part is the hold down kit. No tools are needed to remove for emptying. The problem with the hold down is the rear bracket will flex under load allowing the front to shift clear of the latch. I added an extra brace upright in the center to keep the rear bracket from flexing. No further problems. It is a nice unit overall.

Alan Gomes · Oct 19, 2015

I have the 550P MSD model on my Ericson 26-2. I like the head a great deal. I have it plumbed through a macerator for overboard discharge when 3 miles off. Though the head is great the hold down bracket hardware is garbage. I had a new, easily removable bracket fabricated out of stainless and now it's solid. The thought of 5 gallons of crap flying off those cheap plastic hold downs and across the cabin is scary!

As for removing it: The tank is held in place by the brackets. I typically do not remove the tank. The whole premise behind the MSD version is to plumb it for more or less permanent installation. It's a much easier install than messing with a holding tank and the capacity is surprisingly good compared to a conventional tank since you need to use almost no flush water. For example, as I type this I'm at anchor over at Two Harbors, Catalina Island. I've been on the hook exactly one week, by myself. I'd say I still have at least a few more days left before I'd have to go offshore to dump.

In the three years I've had it, I have removed it a couple of times to cart home for a "deep cleaning." Removing it is not difficult but not something I'd want to do regularly. Overall I'm very happy with this setup.

Peggie Hall HeadMistress · Oct 19, 2015

Gene Neill said:
I'm getting ready to pull the trigger on one of these. It will be the self contained, non-MSD model, although for the sake of this discussion I don't think it makes a difference.
My question is in reference to the hold down kit, which is an optional extra with this model. Can anyone tell me how it works?? Is a screwdriver required to remove it for emptying? I'm looking at images of the potty, and I can't see how the deuce (LOL, accidental pun) the hold down kit actually works.Any other miscellaneous info on the 550P is welcome. Thanks!

No, you would not have to use ANY tools to remove the tank. However, you may want to re-think getting the portable version instead of the MSD version because the 550P holds 5.5 gallons, which means a full tank weighs nearly 50 lbs. That's a LOT to lug up the cockpit, heave over the side onto the dock and carry to the nearest place you can dump it (a lot of marinas won't let you use their rest rooms any more). It's a whole lot easier to visit a pumpout...you can pour a bucket of water into the tank to rinse if out while it's being pumped out. Installing the pumpout fitting and vent thru-hull is an easy job...any good holding tank product (I recommend Odorlos) will keep it odor-free. And you could even put a y-valve in the pumpout line, run it to a macerator or manual pump and thru-hull to be able to dump the tank at sea. I really think you should give this a lot more thought before "pulling the trigger" on the portable model. You can always carry the MSD tank off the boat if you really want to.

CharlzO · Oct 19, 2015

Agreed that you may need some extra bracing for the securing it down part. I have the same, and while I do like the unit, I HAVE had it actually press back and forth to where it's actually come free and rolled all over. Now, that said, it's never leaked a drop, top or bottom. But it's unsettling, obviously. (I get some pretty fun rides on Ontario, so it's easy enough to get those waves and motion to do so). That's the first thing I'm doing on the checklist before going back in, is securing it better.

The way the hold down is designed to work, is that you would just press backwards on the assembly to flex the support so that the front "tab" of the hold down comes free, then lift the entire assembly. You'd have to pull the top off, set it aside, and then take the lower unit to empty it wherever. The problem, as mentioned above, is that it doesn't take much pressure to actually push it to release. so when you have it full of water, and/or waste, there's plenty of weight with motion force to do just that. Then it's all upside down from there.

25yearslater · Oct 19, 2015

CharlzO said:
Agreed that you may need some extra bracing for the securing it down part. I have the same, and while I do like the unit, I HAVE had it actually press back and forth to where it's actually come free and rolled all over. Now, that said, it's never leaked a drop, top or bottom. But it's unsettling, obviously. (I get some pretty fun rides on Ontario, so it's easy enough to get those waves and motion to do so). That's the first thing I'm doing on the checklist before going back in, is securing it better.

The way the hold down is designed to work, is that you would just press backwards on the assembly to flex the support so that the front "tab" of the hold down comes free, then lift the entire assembly. You'd have to pull the top off, set it aside, and then take the lower unit to empty it wherever. The problem, as mentioned above, is that it doesn't take much pressure to actually push it to release. so when you have it full of water, and/or waste, there's plenty of weight with motion force to do just that. Then it's all upside down from there.

I had the same issue until I added the brace to the rear hold down. It would flex allowing the forward slider to disengage and it would move fore and aft. I never had it move over the forward latch but it is indeed unsettling. I am also on Lake Ontario so hello to Little Sodus Bay. I called Transport Canada regarding the requirements of an MSD and the response I got was the unit is acceptable as long as it has the hold down kit. Again, I spoke to Thetford ( Laura Lancewicz) about the weakness of the rear bracket and she said she was turning it over to the engineering dept. for redesign and would contact me when they had arrived at a solution since I said I would buy the new model. That was 2 months ago so I don't know when the design change might occur.

CaptDon01 · Oct 19, 2015

Gene,
I installed the West Marine version several years ago and like the extra holding capacity, but like already mentioned, when it's full, IT'S HEAVY! We like the extra height, more comfortable. Very easy to remove for dumping, no tools required, just pull that piece in the center on the bottom. The gauge started to leak earlier this year, after I guess 3 years of use, and some superglue cured that problem. But, we still miss the full marine set-up we had on our original C-22. Standard marine head with a 12 gallon bladder tank under the V-berth. Worked wonderful, and that's the way we'll go probably next year. Yes more expensive, but I'm tired of having to take the walk of shame.

Don

Peggie Hall HeadMistress · Oct 19, 2015

CaptDon01 said:
View attachment 115778
But, we still miss the full marine set-up we had on our original C-22. Standard marine head with a 12 gallon bladder tank under the V-berth. Worked wonderful, and that's the way we'll go probably next year. Yes more expensive, but I'm tired of having to take the walk of shame. Don

You may want to rethink that, too. Let's do a little math... The average adult uses the toilet an average of 5x in 24 hrs...children a little more often. The average flush including waste from a manual marine toilet is .6 gal (two liters)...that adds up to an average of 3 gal/person/day...two of you will max out a 12 gal tank in 2 days..not even long enough to last through a 3 day weekend. 5-6 gallon portapotties--MSD and portable--hold 50-60 flushes. So you'd need at least a 25 gallon tank to hold that many from any manual marine toilet.

An MSD portapotty isn't as "nautical" as a "standard" marine toilet...but it has no moving parts, so it needs -0- lubrication or other maintenance...just a bucket of water to rinse it out during pumpout The whole system is confined to the head...no plumbing or tank to use up a big chunk of your storage. Think about it.....

CaptDon01 · Oct 19, 2015

Can't argue with math, all I have to go by is my own practical experience, and on a 5 day cruise on the Mississippi years ago with our marine head, the wife and I, and our two daughters, did a 5 day cruise and didn't fill the tank. Our West Marine MSD with the 5.5 gallon holding tank will go 4 days routinely for my wife and I, but I do use a bottle to delay the inevitable....

Don

Peggie Hall HeadMistress · Oct 19, 2015

Gene Neill said:
Ouch. That's not good news.
I've been wondering how long "56 flushes" would last, and I had hoped for a higher number of days than that. Our beloved "Litter Sh*tter" (a kitty-litter-powered Luggable Loo setup) can go that long. The whole point behind this porta potty experiment was to see if we could stretch the intervals between waste dumpings.

It's actually 50-60, not 56. And it should last 2 people at least 10 days...longer if you use the lee rail (which IS legal, btw) and/or go swimming whenever possible. If you have a larger crew and want to increase the holding capacity, you COULD re-route the pumpout hose to a second 12 gallon tank (which would hold twice what the 5.5 gallons the portapotty holds without risk of overflowing it), with a macerator or manual diaphragm pump installed in it to transfer the portapotty contents to it. That would triple your holding capacity. You'd only have to pump out the second tank...turn on the macerator during pumpout to move the remaining potty tankful, plus a bucket of water to rinse both tanks...and you'd still have a maintenance free toilet.

I did something similar on one of my own boats. It had a SeaLand Sanx, which was a combination 9 gallon holding tank and Type I treatment device that was legal on Lake Lanier until the no-discharge law went into effect. I installed an 18 gallon tank--because that was twice the size of the 9 gallon tank--and rerouted the overboard discharge line and pump to it. When the "full" light came on, I hit the discharge switch and sent it to the 18 gallon tank. I knew I could do that twice before I'd have to pump out.

centerline · Oct 19, 2015

Peggie Hall HeadMistress said:
you may want to re-think getting the portable version instead of the MSD version because the 550P holds 5.5 gallons, which means a full tank weighs nearly 50 lbs. That's a LOT to lug up the cockpit, heave over the side onto the dock and carry to the nearest place you can dump it (a lot of marinas won't let you use their rest rooms any more).

It's a whole lot easier to visit a pumpout...
you can pour a bucket of water into the tank to rinse if out while it's being pumped out. Installing the pumpout fitting and vent thru-hull is an easy job...any good holding tank product (I recommend Odorlos) will keep it odor-free. And you could even put a y-valve in the pumpout line, run it to a macerator or manual pump and thru-hull to be able to dump the tank at sea. I really think you should give this a lot more thought before "pulling the trigger" on the portable model. You can always carry the MSD tank off the boat if you really want to.

when it comes to this subject, we all need to be reasonable, honest and keep in mind what really happens.

I dont and wont pretend things are different than they really are... the following is a fact of life.
we all are going to eliminate ourselves when the urge arises and if we do it in a container that has to be dumped or pumped before we can go again, its GOING TO GET DUMPED OR PUMPED... unfortunately this happens within the 3mile limit too often. (there was a time when it was common practice and legal to dump wherever and whenever)...
in addition to a 34ft boat with a fixed MSD system on it, I have a small boat with a portable pottie onboard.
in the places we use the smaller boat I have found the portable potty much more convenient than a permanent mounted MSD device. the reason is that most of the lakes we trailer the boat to does not have pump outs... with the portable, we have the option of carrying it to the nearest land toilet and dumping, or if we are very remote and there are no land toilets, we can dig a hole and dump into it..... .
with an MSD device there would be only one or two options, one of which is to pull the boat, derig, and trailer to a marina that can pump us out, then return and relaunch... OR, if the system is fitted with a self discharge pump, pump out into the lake, which of course, even with the portable unit there is that illegal option.. but im smart enough to know which option is the most reasonable and best for the environment of the body of water that im on...

an msd device is not always the best option, but sometimes its the only option available due to the local laws of the area.
a portable may have to be carried out of the boat to empty it, but at least there is also the option of pumping it out at a pumping station if one is available.... after having both types, I will always recommend the portable potty over a fixed MSD toilet on a on a small trailerable boat... because the msd has limited dumping options, and with the portable one has all the options of the MSD plus other options that allow for better enviromental sanitation practices in more areas... if only one would use them.
the op has a smaller boat on a lake, and even though we dont know if he trailers anywhere else, or if there are pump out stations where he is, I am well traveled sportsman here in the northwest and its surprising how many lakes are open to boaters that need to periodically eliminate themselves, yet there are no facilities for pumping/dumping from the boat..... carry out only.

I know quite a few people who have bigger boats and are ignorant and readily admit that they pump out whenever and wherever the tank becomes full.... and then others that make every effort to use the pump-out station, but when the pump out station is out of order, they still find a way to dump the holding tank. Hmmm... maybe a "carry out" portable system should be the ONLY system allowed, or a MSD without "self discharge" options?

25yearslater · Oct 20, 2015

Gene Neill said:
25yearslater, can you describe the reinforcement you did? The potty is on the way, but I held off on the ($30!) mount, even before I saw all these great responses. It just seemed like robbery for what looks like, and evidently is, a $2 part. I thought I might fabricate my own, once I got a look at the unit, and I still may. I want it bomb proof. We stand our little Daydream on her ear now and then, and whether or not the unit could possibly leak, I do NOT want to hear fifty pounds of poop, water, and potty crashing around he cabin at the worst possible moment!

I used a 3/8 piece of nylon flat stock I had laying around. All it is, is essentially a third rib in the center of the rear bracket cut in the shape of the edge profile. I screwed it in with two #8 sheet metal screws in the upright edge. I can draw up a sketch later today if you would like. Now when Ontario beats me like a step child at least I don't have to worry about the stuff hitting the fan.

Kermit · Oct 20, 2015

Peggie Hall HeadMistress said:
...And it should last 2 people at least 10 days...longer if you use the lee rail...

Oooohhhhh.... The LEE rail. That explains a lot about what I was doing wrong.