Home Made black water tank

[Wavery]

Finished........sort of


Installed the "Rotary Jet" clean-out with the water hose attachment going through the outside shower opening and exiting under the trailer so that I can dump, then flush the tank without opening the trailer.

The water supply for the toilet is the same as most of the others have posted for a flush toilet installation. That was probably the easiest part of the entire job.

One regret is that I didn't select a smaller toilet. This one is pretty large for the space but takes up no more room that the original recirculating toilet.

My wife is going to put some mosaic tile on the front of the tank and side of the tub to put a nice finishing touch.

[larsdennert]

Looks like the added volume over the sealand tank comes from both the height and width. You went all out. I recently put a sealand in and haven't used it yet. That was some work but no where the amount you've put in.

[rich2468]

Hey Wayne (and others),
It looks like you have both a vent line (exiting through your lower shell walls) and also a toilet tank clean out line running under your tub and down through the floor.

Am I understanding correctly that you do have the sidewall vent? If so, can you share why you have both?

I installed the Sealand tank/toilet combo unit (which I had a floor drain spun-welded onto) and only attached a clean-out plumbed similarly to yours. (I plugged the vent hole of my Sealand tank.)

My thoughts are that the clean-out provides the venting function when not having the water flushing through it to the toilet tank (during cleaning) and when it is being used as a clean-out line I have the outside toilet tank gate valve open supplying plenty of air flow.

In a marine-use it's obvious why the vent is needed- but I don't see how it would be in our camping use with a clean-up.......

Am I seeing things wrong?






Rich and Lynn
2021 2922KB

[Wavery]

Originally Posted by rich2468

Hey Wayne (and others),
It looks like you have both a vent line (exiting through your lower shell walls) and also a toilet tank clean out line running under your tub and down through the floor.

Am I understanding correctly that you do have the sidewall vent? If so, can you share why you have both?

I installed the Sealand tank/toilet combo unit (which I had a floor drain spun-welded onto) and only attached a clean-out plumbed similarly to yours. (I plugged the vent hole of my Sealand tank.)

My thoughts are that the clean-out provides the venting function when not having the water flushing through it to the toilet tank (during cleaning) and when it is being used as a clean-out line I have the outside toilet tank gate valve open supplying plenty of air flow.

In a marine-use it's obvious why the vent is needed- but I don't see how it would be in our camping use with a clean-up.......

Am I seeing things wrong?






Rich and Lynn
2021 2922KB

objective of the vent is to have no positive pressure in the tank so that when we flush the toilet, no pressure is causing splash back when the toilet valve is opened. It also releases methane gas build up.

Also, when we dump, we want a good size vent to allow air to enter the tank as the black water exits. I keep the fresh water flush valve capped (as in the picture). It will not allow any air transfer. Even if it were uncapped, it would not allow enough air to allow proper waste dumping. The other issue is that the garden hose connector is below the black tank. If the cap is left off the tank, I can see black water being released if we tow with the tank full. Methane gas is lighter than air, so there's that. Methane gas would be released into the camper when the toilet is flushed.

Bottom line, I don't think that the small amount of air that might pass through that Camco flush valve would be enough to do what I want.

[rich2468]

Thank you for sharing your impressive handiwork. Working in the limited space inside a TrailManor is quite difficult and you've done a great job of retrofitting your new tank and toilet.

Over-venting is certainly not a problem, but with our small plumbing system and limited vent pipe routing options doesn't appear required. I've now been using a combined cleanout/ vent line for over 6 months and the amount of pressure equalization of the holding tank has been fine. My cleanout has a flow-through spray head of the type normally used in brew tanks; so the design is different from the Camco Tornado unit which may be the difference allowing adequate pressure equalization via the rinse-out.

[Boyddeck]

Looks great but i ran across this on amazon icon 437 22-1/2" x 18-1/2" x 6" Bottom Drain Holding Tank https://a.co/d/fBr8Pgc

[Wavery]

Originally Posted by Boyddeck

Looks great but i ran across this on amazon icon 437 22-1/2" x 18-1/2" x 6" Bottom Drain Holding Tank https://a.co/d/fBr8Pgc

That tank is rated to hold 8 gallons. That may be OK for a weekend but we normally camp for 4-5 nights. My home made tank holds 13.5G. If I would have made it an inch higher, it would hold 15.3G.

We just got back from a 5-night beach camp-out with no hook-ups. We use the toilet exclusively and I tow home with it full. I have a dump station at home. When we got home I found that there was enough room for another day.

[Deb Mac]

Looks very nice! Great job! You are handier than I am. I don't think I would be prepared to take on a black tank built from scratch. Not yet any way. I have the Poor Man's with the icon tank. But that additional volume would be very nice to have. Hats off to you.

What size marine vent do you have through the wall there? Looks like 3/4". I could only track down a 1/2" in a right angle. When I find a 3/4 at something less than a small mortgage (I'm in Canada and some of these little items come at a premium by the time they get here) I'll change it out

Again - very nice!

[Wavery]

This is the vent:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It works really well. It's important to have a good sized vent so that when you pull the handle to dump, air replaces the volume that is evacuating the tank at a rapid rate and no vacuum occurs inside the tank. That gives you a nice clean "Dump". Another trick is to have someone hold down the flush pedal on the toilet while you open the gate valve outside.

[Deb Mac]

“No longer available”. I found a straight vent that might work out if I use a flexible enough tube - I am using silicone. I’ll see if I can work with the straight one.

I also considered trying something along the lines of a battery box vent and use a 1” tube. Still thinking about that. Or teach one of the dogs to flush the toilet