Mount Grey Water Tank

heimlich

2003 International 3800 T444E
Joined
Sep 30, 2023
Posts
248
Location
Houston, TX
I am trying to mount my grey tank. I've seen multiple postings on here using the threaded rods and unistrut. Those worry me that they will move around side to side and eventually wear the threaded rods. I saw someone else used the buyers box mounts. I called buyers and they said that their brackets would break if I tried to use them with a water tank. My tank is 100 gallon capacity. I would empty immediately after camping so it wouldn't stay there long.

I have a metal pan built for my tank. I put a picture of that below here. I also put a picture of where I want to mount it.

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My plan is to use the existing holes in the frame rails to attach a heavy duty welded rack. Your bus has quite a few pre-drilled holes that may make it possible.

Similar to how this LP tank is mounted:

https://www.skoolie.net/forums/f10/made-a-heavy-duty-lp-tank-rack-43675.html

Thinking I may put the tank in the center so it can be supported from both sides.

It's not a huge job if you have a welder or welding friend and a metal supplier nearby.
 
I called buyers and they said that their brackets would break if I tried to use them with a water tank. My tank is 100 gallon capacity. I would empty immediately after camping so it wouldn't stay there long.

Water is about 8 lbs per gallon.
Thats 800 pounds when full.

Rationalizing that you dump after camping,l…. What if the dump site is not nearby ?

Build it so it can carry double the weight and you’ll be just fine.
 
I agree, the threaded rod and unistrut mounting jobs look inadequate. Not as bad as the 2x4 frames or the tanks held on by paper thin galvanized strapping, but still, probably not up to the task we're asking of it.

If you can weld, do that. If not, use lots of steel and lots of bolts. I'm not smart enough to figure out all the possible dynamic loads, so I put in X bracing wherever I could to hopefully handle forces in any direction. Below is a pic of the frame for my 75 gal. Gray tank. We've driven loads of rough roads in the 10k miles since I installed it and it shows no signs of wear.
PXL_20230507_221231200.jpg
 
For each of my 110-gal water tanks and for the 115-gal grey tank and 65-gal poo tank I used 1/2" threaded rod as hangers, ten per tank except for the poo that has only six. Each tank sits on a substantial steel support frame and is sheathed on all four sides and the bottom with 1/2" plywood. To absolutely eliminate all horizontal movement I enclosed the top of each tank within a frame bolted to the frame rails and/or under the floor (Crown uses 1.5" thick marine plywood for their floors). This way the tanks cannot move at all, without any need for cross-bracing or diagonal struts. Simple, easy(ish), totally effective, 100% reliable.

John
 
This is good subject matter for the skoolie certification we're planning on building. Framing seems best for this situation. Rods do allow for sway. You could weld the rods to the frame, but it's also safer to have like a metal plate welded to the same frame to go in front and back of the tank to prevent shift up at the top rather than try to rig something to stop horizontal movement at the bottom of the tank as it's heavier there. Tanks with baffles are also better to own to help prevent the horizontal force as much, but also cost a ton more.

But a small plate in front at the top and and back at the top to hold it in place from shifting so much is best.
 
Threaded rod and strut will hold it no problem. Very easy to make it not move. It holds a lot more than you would think. We hang plumbing equipment and tanks with it all the time. Also it can be taken down easily if need be.
 
i did a different tank setup. probably less robust than many of these others.

my tank is a traditional tank off a bumper pull. its only held on by the upper edge of the tank. there is a flange thats about an inch larger than the tank on the top side that the tank hangs by.

a bumper pull usually puts wood screws thru the flange to the floor of the camper.
i built a frame to hold the flange and the tank hangs underneath.

when the tank is full, it bulges downwards an impressive amount. after the first year i put a helper support strap in the middle so i felt better.

the tank wont last forever, but i think it will uv crack before the mount breaks. its prbaly been 10 or 11 years since i installed it.
 
This is my tank set up.

Grey tank is hung against the frame with thread rod and angle steel. Added supports in the middle for center supports. I have angle iron on top of the frame. No drilling into the bus frame or bus body for the grey tank.

The black tank is above the grey tank between the frame and outer side skirt. I bolted 90 degree angle steel to the floor supports.

I drove the bus with cleen water full in both the tanks and nothing has moved.
 

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I like how you did that with the supports across the frame that holds it in place.
 
Nice job with the tanks. Are you gonna slide anything between the tank bottom and the steel bracket, for rubbing protection ?
The weight of the water might bulge out the tank slightly, and with time and road vibrations might wear a groove in the tank ????
 
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For my tank I have some ratcheting straps I am going to put around the tank to hold it down. I will need to build some supports to keep the ratcheting straps from pushing down and in on the tank.
 
Nice job with the tanks. Are you gonna slide anything between the tank bottom and the steel bracket, for rubbing protection ?
The weight of the water might bulge out the tank slightly, and with time and road vibrations might wear a groove in the tank ????

I used foam tape and automotive weather stripping to prevent the chaffing.
 

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I've got the tank mounted. I had drilled out 9 1/2 holes for 5.9 bolts. I was only able to get 6 of them in. I had to lift the bus up in order to get the tank to slide under the side.

How much clearance do these things need? I'm hanging down about 7 or 8 inches below the skirt.


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My generator bracket has 10+ inches of clearance. No issues with it. Even if I do hit something I might damage it but should not fall off. Attached with 2- 4 inch "C" channel brackets I welded up bolted to the frame. Way over kill.
 
you're fine.

mine hangs down to the bottom of the rims, never been a problem.

I'm with you. I believe nothing can contact with roadway with deflated tires to be deemed safe.

In other words. With flat tires all weight of the vehicle still has to be on the wheels to maintain control.

For stoning......if your drive all highway. Let it roll. If your driving gravel roads. Add protection if you desire. I just add mudflaps.
 

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