A poor man’s Sealand alternative

[theDudeAbides-SMB]

So I couldn’t get myself to pay for the Sealand 711 and we didn’t want to spend another season with the Thetford in our '04 2720. Looking around I found this 8.5 gallon holding tank made by Icon that is designed to have a toilet direct mount and reinforced to support the weight of a person. I ordered one from Amazon ($140) to see if it might work.

It seemed plenty sturdy so I decided to continue. I found a Thetford low profile toilet on eBay new for $95. For venting I decided to use a marine through hull vent from Amazon.

 

[theDudeAbides-SMB]

The tank is 6” tall, so to secure it I built a box. I ripped a piece of 1x8 pvc trimboard down to 6” wide to build it with.

Then I drilled holes around the lip of the tank to secure it to the box with stainless screws.
I did this before opening the trailer. Once I removed the old toilet i realized I was going to have to modify. The discharge on the tank was located 3/4” closer to the frame rail in the trailer and 2” toward the tub from the hole in the floor. The 2” would be easy to trim off the existing hole but the 3/4” would put it on the trailer frame. Luckily the mounting flange on the tank is 1-1/4”, so I was able to trim off 3/4” from the back side.

Now I had to modify the box I built for the shortened back flange AND for the wheelwell interference I didn’t anticipate.

 

[theDudeAbides-SMB]

Keep in mind the box only secures the tank in place, the tank itself is structural. The box I then screwed to the floor with some small L brackets and then screwed the tank down.

 

[theDudeAbides-SMB]

For the vent I made a hole in the side right above the line from the tank.

For the water supply I enlarged the hole the power for the old toilet went through and ran pex to under the kitchen sink so it would be easier work with the fittings. I terminated the line with this push fitting supply line and valve combo.

 

[theDudeAbides-SMB]

All in all it turned out pretty well.

Here you can see the discharge is the same distance from the frame rail as the original, just moved 2” to the rear of the trailer.

I’m currently repairing a crack in my grey tank so I haven’t completed the exterior plumbing yet. It’s easy though. A small stub of pvc glued to the threaded coupler in the bottom of the tank, then join to the old 3” with a rubber coupler. Then shorten the 1-1/2” side by 2” and reconnect with either a glued coupler or a rubber coupler. I will post pics once that part is completed.

 

[theDudeAbides-SMB]

Costs
Icon holding tank $140 on Amazon (currently listed at $147)
Thetford Aqua Magic low profile $95 on ebay
Marine through hull vent $12 Amazon
Push fittings and pex tubing (1 elbow, 1 tee, and 1 valve/supply line combo) $25 at Menards
3/4" vinyl hose for the vent $1.50 at Ace
1"x8"x8' pvc trim board $23 at Menards
Stainless screws ~$5 at Menards
3" and 1-1/2" rubber couplers ~$8 at Menards

I know there are a few things I'm probably missing but as you can see it came out to right about $300 and could have been cheaper with other choices.

 

[klpauba]

Nice job on the installation and a worthy alternative to the original toilet.

 

[HoMiPa]

Great job on this project, and a great tutorial with all your photos & explanations! This should be pinned, or saved, or something, as a reference document, so no one has to reinvent that wheel.

 

[Kidkraz]

Nice work with the mod.

 

[Bill]

Great job on this project, and a great tutorial with all your photos & explanations! This should be pinned, or saved, or something, as a reference document, so no one has to reinvent that wheel.

Holly -

I agree. This is one of the cleverest, and most useful mods, I have seen. I have copied the posts into the TM Technical Library. Later today I will figure out how to merge all six posts into one big tutorial, to make it easy to print out.

Dude -

If you make further posts here in the forum, I will copy them into the same thread in the Library. I note that all your pictures currently reside on a photo-hosting site, instead of being attached to your posts. Unfortunately, photo hosting sites tend to disappear with little or no warning, and here on the forum we have lost a lot of good information when this happens. To prevent this, I may try to copy out your photos, and attach them to your posts so that they are stored right here on the forum. Copying and attaching is a long process, so please be patient if you see some strange things going on.

Thanks for the invention, and the clear explanation.

Bill

 

[oldstick-TMO]

Nice work indeed. The sealand tank is only maybe a gallon more than that. An excellent idea and way less cost than the Sealand.

 

[Shane826]

Looks awesome. The one complaint I have with my SeaLand is it seems to leave little to no foot space in front of it. Yours looks a little “roomier”.

I’m gonna get me one of those vents. I currently have a hose going through the floor for a vent. It works fine, but I want to put a Camco Toronado tank tinder on the tank. I could then put a hose adapter on my current vent hose and vent the tank through the wall like you have.

Again, nice job!

 

[theDudeAbides-SMB]

Thanks, for the wall holes the outside hole is 1-1/2” and the inside is 1”. I happened to have both in forstner bits which worked perfectly. I had 3/4” rubber and metal washers which I used on the inside. Came with an o-ring for the outside.

 

[bheisser]

nice work

 

[Casey Freswick]

Great Idea

Bought my Sealand some time ago and just finished installing. it works great but would have followed your pattern. Just one thought. I installed my Sealand and then took it all apart to add one piece. I was a little concerned that the 3 inch rubber connection might wiggle loose. So I bought a metal 3 inch mounting bracket (<$2.00). I mounted it it on the floor and had it drop down. Now there is a bracket holding the piping under the tank up, not just the hose clamps. I am glad I used the rubber connection (that came with the Sealand) rather than a pipe connecter because if I ever need to remove anything (as I already did for the bracket) the task was and will be far easier. I also cheated and used shark-bite fittings for the fresh water. Everything is connected and leak free after being tested with a direct connection to my home water supple. Ready for the new season. Once again, great idea.

 

[oldstick-TMO]

Bought my Sealand some time ago and just finished installing. it works great but would have followed your pattern. Just one thought. I installed my Sealand and then took it all apart to add one piece. I was a little concerned that the 3 inch rubber connection might wiggle loose. So I bought a metal 3 inch mounting bracket (<$2.00). I mounted it it on the floor and had it drop down. Now there is a bracket holding the piping under the tank up, not just the hose clamps. I am glad I used the rubber connection (that came with the Sealand) rather than a pipe connecter because if I ever need to remove anything (as I already did for the bracket) the task was and will be far easier. I also cheated and used shark-bite fittings for the fresh water. Everything is connected and leak free after being tested with a direct connection to my home water supple. Ready for the new season. Once again, great idea.

I had to do something similar. I also used a rubber collar with clamps to connect to the down spout of the Sealand. Then another one to reconnect the grey water pipe after having to cut it for moving everything over an inch.

I was then getting a small amount of "sag" in the outside pipes, just enough to cause a drip where it exits the gray water tank. So I rigged up a hanging strap to support the plumbing at its original height, enough to stop the leak.

 

[theDudeAbides-SMB]

Thanks for the suggestions about supporting the pipes. I’ve completed my tank repair. So now I’m tackling that part tomorrow and was thinking it would be a good idea to support them.

The fittings I used on the water line are the Watts brand of sharkbite fittings. They have worked just as well for me in other projects and are cheaper.

 

[theDudeAbides-SMB]

Finished up the exterior work this morning minus some sort of support bracket. I flipped the 3” valve bc the grey tank plumbing prevented it from fully opening.

 

[Larryjb-HILO]

Interesting concept. Will probably keep the recirculating toilet because we would likely be emptying the holding tank too often for my preferences, especially if we are boondocking.

With regards to the venting, has anyone tried venting using a flexible hose to the roof? Combined with a small 12 V fan, this may eliminate most odors from even the recirculating toilet.

 

[jasonv31]

Great job! I have a 1996 Trailmanor 3023 that I purchased, it was sitting up for 6+ years... I'm looking at options for the toilet, as I expect that getting the old Thetford working may not be possible. This will be a possible inexpensive option.

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