waste tanks

[BG6]

The only problem with barrels is wasted space.  If a typical 55 gallon drum (24" x 35") was a rectangular tank of the same dimensions, it would be 87 gallons.  That's 58% if my math is right.

They offer some advantages, though in using drums on their sides.  If two of them are together, you have room between them for a PVC pipe to hold your dump hose.  If you get barrels with removable tops, you can easily put in BIG fittings, they will empty completely (if you tilt up the back end) and -- most important -- you can save hundreds of dollars buying used food-haul plastic barrels.

On the other hand, rectangular tanks are easier to install and secure.

[Lin]

As mentioned, it is only wasted space if you don't use it.  With a little planning, you could probably run some pipes and wires in the missing corners and avoid them being in the way somewhere else.

[bevans6]

My earlier hesitancy was because the drums that I've seen had removable tops, but these ones being one piece would be a ton better than a drum that the top might come off of...

One thing about round tanks laid on their  sides - the bottom is always the bottom even if you are on a little bit of a hill when you dump.  I always end up with a few gallons that won't come out due to the tilt of the bus.

Brian

[BG6]

My earlier hesitancy was because the drums that I've seen had removable tops,

Any container approved for shipping must be tested.  A drum, intended to ship liquids internationally without being in an outer container, is filled then drop-tested.  If the top were to come off, it would fail the test.

All of the food-grade screw-top drums over 20 gallons that I've ever seen were certified for international shipping. The addition of a small set-screw through the lid into the drum threads would pretty much eliminate the risk of losing seal due to lid motion.

[Stormcloud]

I have done exactly what you propose....I used 2 carwash plastic barrels for my 'first' installation of black/grey tanks.

It worked, and worked reasonably well. The toilet dumped into one, and everything else dumped into the other, and could overflow into the black tank, if needed.They both vented through the joined overflow and through the bus roof.

The black tank was first in line to empty; when done, I opened the grey tank, and it would wash out the hose, then closed both tanks.

There was a lot of wasted space, and there were a lot of fittings and urethane adhesive (aka Sikaflex) used to make sure the fittings dont leak where they mate to the barrels.(and believe me, you dont want these fittings to leak)

This version lasted 2 years; I then purchased one 100 gallon tank (identical to the fresh water tank) for a combination tank, and replaced the barrels.
Only 2 fittings to worry about (below waterlevel), and much better use of space.

In retrospect, I should have put the $$$ from all the fittings I required on the barrels into the purchase of the single poly tank, and be done with it once and for all.

But....YMMV.

Best regards.

Mark

[BG6]

Where did you get your tank, and what did you pay for it?

BTW, the best thing I've ever found to seal fittings in these is Shoo Goo.

However, my suggestion to anyone planning to use barrels is to get the ones with tops which screw on or -- better -- are secured by Zeppo clamps, then lay the barrels down on their sides next to each other.  You do your plumbing through a flat plate and can work on both sides of it, using standard gaskets which are supported by the fittings.

Figuring $25 each for two barrels (I see them for $10 on Craigslist), plus 2" greywater fittings between them gives me a guesstimate of about $75.  I am not counting fittings which would be necessary on any tank setup, such as the dump valves and hose connector, but just those which two barrels would need.

The only problem with most screw-lid barrels is that they have a shoulder, leaving you with a couple of inches of undrainable depth.  This isn't a major problem if you add a rinse nozzle to spray clean water into each tank.  One guy I know who uses these threw in a couple of round stones about 3" in diameter, which roll around when he's driving and breaks up solids and sediment to make them rinse out better.  Once a year, before he hits the road again, he throws in another stone.