Best way to hang a black water tank

[Tenor]

My black water tank needs to hang from the floor of my MCI 7 in the rear baggage bay.  It is a heavy gauge black plastic tank with notches in the bottom edges for strapping.  Is plumbers tape (I think it's called that, strip of metal with holes down the center) strong enough for a 40 gal tank if the straps are attached to the metal cross braces?  My fresh water tank and grey water tank are beneath it, but not in contact.  Although, if I box them, they might contact and support.  Anyway, what about straps?  Thanks!

[gumpy]

Ya gotta ask yourself one question... do you feel lucky?  Well do ya punk?   

Personally, I wouldn't hang 40 gallons (i.e. ~350 lbs) of sewage with itty bitty partially broken straps. Think of the mess you're gonna have when they give way!

I might consider using 1/8" steel strap if they have the notches for hanging with straps, but I'd prefer to build a frame out of angle iron for them to sit in.

craig

[Kwajdiver]

I agree with Craig 100%, why would you want to hang it.  Build (or have built) a rack.

My 2 cents,

Bill

[gus]

Amen to what Gumpy says.

The black water tank is the very last thing you want to hang. No other tank outside of fuel will make the mess that thing will when it lets go!!

You don't even want it over the fresh water tank for any reason if for no other reason than it could spring a very small leak into the fresh.

[TomCat]

Here's how I hung my 75 gallon black tank from the floor of my Thomas... http://www.zoto.com/site/#USR.jsbird69::PAG.detail::c8fe6ad125b0c4108a9476c0a54b6d14

Jay
87 SaftLiner

[tekebird]

Question, why did you design it that way.. Logic would dictate you put the poop tank on the floor and hang your fresh if hanging it at all

[Tenor]

Here's why the layout as it is.  The 2 tanks I am using for fresh and grey are approx 80" x 26" x 11".  With the drop in the center of the bay, I can stack these two 100gal tanks on each other and it only leaves about 5 inches on the drivers side for plumbing.  The black tank will be on the passenger side with the drain running along the forward bulkhead to drain out the driver's side.  It fits beautifully  above the fresh and grey taking up that wasted space.  It is no problem to build an angle iron frame.  My 4905 had that for the fresh tanks.  2 actually, totalling 80 gal.  bolts had been run from above to support it.   In fact, it had a 50 gal black water tank hanging from the floor with the grey water below it too.  Never had any problem with them, and they had been in there at least 20 years, so I wasn't concerned about designing it to hang.  I really appreciate the warnings!

I'll do some more measuring, but the easiest way may be to support it from below, using the boxing (probably 3/4 plywood) I plan to build for the other two tanks as part of it's support.  I certainly don't want any problems. 

[tekebird]

I would just put it on top of the other two with frame support if you wanted to use these tanks.

personally i would just go with the two tanks dark and clear.

[TomC]

TomCat- that is a very nice mounting for supporting the tank vertically-probably will be strong enough.  But it won't stay put through serious braking actions unless you install a serious (translated 3/8 x 2" angle iron) horizontally to keep the tank from moving back and forth.  Most people forget about horizontal for and aft and side to side forces when travelling down the road. 

I made a 3/4" platform with the for mentioned angle iron around the perimeter.  Then tied into the cross members both vertically and horizontally for my tanks with more angle iron that are hung underneath (85gal gray and 45gal black).  In 12 years, no problems.  Good Luck, TomC

[Nick Badame Refrig/ACC]

Hi Tenor,

I used a steel stand to raise my black water tank. "1 inch angel iron" I raised it for internal dump valves.

Ah.. I'll just post a pic.

Good Luck
Nick-

[Chaz]

Without a doubt, frame it up. It makes me clinge to think about the mess you could have. OMG!!!
  I would overkill it to death!! 

     Chaz

[TomCat]

TomCat- that is a very nice mounting for supporting the tank vertically-probably will be strong enough.  But it won't stay put through serious braking actions unless you install a serious (translated 3/8 x 2" angle iron) horizontally to keep the tank from moving back and forth.  Most people forget about horizontal for and aft and side to side forces when travelling down the road. 

I made a 3/4" platform with the for mentioned angle iron around the perimeter.  Then tied into the cross members both vertically and horizontally for my tanks with more angle iron that are hung underneath (85gal gray and 45gal black).  In 12 years, no problems.  Good Luck, TomC

Tom,

Thanks for your comments, and normally that would be a good catch! However, the way I installed my black tank enclosure, it wasn't necessary for me to cross brace the mount.

I built the 75 gallon, 3/8 poly, black tank into a 3/4 inch marine plywood box, then put a 4x4 block on end, between the lower surface of the floor, and each upper corner of the top of my tank box.
As I tightened up the 8 nuts which raised the frame/box, it effectively clamped the box/tank assembly between the tank frame and lower surface of the floor, which has it very secure.
It hasn't moved so much as a millimeter in more than two years of heavy use.

However, thanks very much for watching out for any errors, and please don't stop! 

Jay
87 SaftLiner

[Reddog]

My setup is very similar to Toms, an angle iron frame hanging from all thread, I didn't build a box to enclose it, but did add a expanded metal "floor" for protection:
http://photos.imageevent.com/reddog/1990thomasbuiltbusdogbus/large/IMGP2097.JPG
  I made pipe spacers to allow for tightening the all thread securely without crushing the tank. A drop center tank would take a little more crafting, but I wouldn't trust anything to that perforated strapping.
Doug Engel, Gunnison, CO

[Jerry32]

I hung both of my black and gray tanks with 1/4" X 1 1/2" straps hanging from the steel framing inder the floor. Then I used 1 1/2" angle Iron rails to support it with straps tying the rails together. That gets the tanks that need a drain above the floor so that my sewer solution can be attached inside the compartment  and the drain hose exits a small hole in the floor that also is where the 50 amp power cord goes and the TV and satelliite lines come in . Alkkl works great and my water tank is on the floor and all plumbing is sealed so that no contaminates can enter. Jerry

[kyle4501]

To each their own, but I'll make every effort to keep my fresh water as safe as I can.