TrailManor Owner's Forum  

Go Back   TrailManor Owner's Forum > TrailManor Technical Discussions > Plumbing
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 07-14-2020, 12:27 PM   #1
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default A WARNING to owners of a Thetford Curve (and other porta potties)

Years after the untimely demise of my Thetford Electra Magic, I replaced it for a Thetford Curve, which is basically a glorified portable toilet for which you can buy a platform to mount it to the floor.

Last week we took a long trip that included several hours in searing 105 degree heat, which also included an elevation gain from our origin at sea level to about 7,500 feet at our destination. The toilet was empty for the trip, aside from fresh water in the flush tank.

Upon arrival, the toilet was not sitting flush on its mount. Before realizing what had happened, I opened the flush valve to put in some chemicals and was immediately greeted with a very forceful spray of quasi-clean water from its last rinse that went up my entire arm, and bits reached the ceiling. The combination of the heat and elevation gain built up ALOT of pressure in tank, which I had just released. I also thereafter realized it wasn’t sitting flush on the floor because the base had bulged.

Fortunately, the base flattened out after an hour or so, but for me, that was a demonstration that should it ultimately fail, it very well could blow out the bottom of the toilet. Portable toilets are not vented, unlike permanent traditional RV toilets, and obviously the Thetford Electra Magic (which has the ultimate vent), so this has to be taken into consideration. Use caution when in extreme heat and/or when making significant elevation gains.

Are the cassettes in a cassette toilet vented? I’m guessing they might be since the cassette would not be in a living area, but at least in looking at photos of the Thetford C223-CS Cassette Toilet, I don’t see one (I see a blue button there, which I presume is a push button vent to aid in emptying the tank.)

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 07-14-2020, 03:45 PM   #2
Kidkraz
Site Sponsor
 
Kidkraz's Avatar
 
Join Date: Mar 2013
Posts: 1,037
Default

Yes, that is the flush button and I have had that same thing happen me. I was lucky as you. So, I always open the dump valve before opening the lid to dump in my chemicals.
__________________
2013 2619
80 watt solar panel/swing hitch/low profile A/C.
Enduro 4445 caravan mover
2016 Dodge Ram 1500 V8 Hemi
Installed powered folding tow mirrors

Stopped playing with airplanes, now I just enjoy watching them fly by.
Kidkraz is online now   Reply With Quote
Old 07-14-2020, 06:31 PM   #3
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

My resolution to the problem in subsequent days of travel under the same conditions was cracking the flush vale open slightly, maybe 1/8”-1/4”. I did this with waste in the toilet — maybe 1/2 full — and even after 400+ miles of travel, there was no evidence that any waste crept up into the bowl. And even if it did, just as with the Thetford Electra Magic, it should flow right back down into the tank. That solves both the “Old Faithful” eruption, and the potential tank bursting under pressure.

So going forward, I think my default mode of travel with the toilet empty or with some waste is to crack the valve.

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 07-18-2020, 11:49 AM   #4
wbmiller3
Site Sponsor
 
wbmiller3's Avatar
 
Join Date: Oct 2004
Location: Southeast of Houston, Texas
Posts: 1,089
Default

Since basically anywhere is higher elevation than Houston, we've had similar problems with closed containers often....but never with the toilet!

Great post, thanks.
__________________
Bill
https://spaceflight.training
https://www.facebook.com/wbmiller3
2018 F150 towing 2001 2619; lift kit & 15" wheels
wbmiller3 is offline   Reply With Quote
Old 07-18-2020, 01:04 PM   #5
Bill
Site Team
 
Bill's Avatar
 
Join Date: Feb 2003
Location: The mountains of Scottsdale, AZ, and the beaches of Maine
Posts: 10,088
Default

I'll admit that I have not used a cassette toilet, so I went to the Thetford web site to learn a bit. Right away, I wasn't too impressed with the Thetford video showing a guy dumping a full cassette of sewage into a stainless steel sink at what looks like a fish-cleaning station (a yummy filet of ... what?), or perhaps a hand-washing sink. And then sticking the sink's fresh water hose deeply into the cassette to flush it out. But I know you guys would never do that, right?

Anyway, regarding the pressure build up in the cassette, it would seem to me that a teeny tiny pin hole would be enough to keep the pressures equalized. Choose a location where the contents are below the pin hole both when cassette is in the toilet and when you are toting it. Then heat up a needle, and run it through the plastic. A hole this small would not dribble under any conceivable splash conditions. And if you truly don't like it, it is easy to squeeze a drop of glue into the pinhole to seal it up.

Seems too simple. Have I missed something?

Bill
__________________
2020 2720QS (aka 2720SL)
2014 Ford F-150 4WD 5.0L
Bill's Tech Stuff album
Bill is offline   Reply With Quote
Old 07-18-2020, 08:05 PM   #6
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

Interesting idea about making a pinhole, Bill. Great idea. I guess I would consider doing that if cracking the dump valve didn’t work, and actually, maybe I will still consider doing that once I take a closer look at how the two halves of the toilet are sealed when connected. With the dump valve cracked open, I definitely don’t want black water coming up out of the tank and then leak out in between the two halves.

I do always rinse out the tank when emptying the cassette, but I don’t use freshwater. I have an older windshield washer fluid jug, and fill it with grey water to take with me to dump, and use it to rinse the toilet.

Having had an Electra Magic (and liking its overall design, but not its build quality), a cassette toilet is not a good solution for those folks who regularly camp at RV parks. It’s definitely more work, and far less “elegant”. But for those who dry camp regularly, I think it works better than emptying a black tank (or the Electra Magic). The cassette can be dumped in any toilet, porta-potty, outhouse, etc., so not only do you avoid a trip to a dump station on the way home, which could be miles out of the way, but you can dump during an extended stay without a tote.

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 09:29 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 2022 Trailmanor Owners Page.