water storage under vehicle

[cparcell]

Well after a long winter and terrible fall last year I'm finally ready to assemble our new SC xterra for overlanding. Our last rig was the target of a ************ who decided to run a red light and undo all the money and time put into it.
So for the last 3 MO I have kinda had cross feelings about our 3 inch body lift, custom 3 inch body lift custom bumpers and the tall height of a xterra on a 3 inch suspension lift and 34 inch tires.
Until the idea popped in my head today. While considering water storage to accommodate the wife and I on our weeks exploration adventures, I looked at roto packs, Jerry cans, pvc pipe tank setups etc. Then I realized, I messed up and ordered a 3 inch body lift, but that added a lot of space under the rig to mount a tank high in the frame rails under the body.
So for tanks I'm considering a holding tank 34x6x54.

Is this a bad idea, considering the weight is low and I don't want to load more crap on the rack or rear bumper

 

[Herbie]

Generally, having that weight low is super nice. That's a HUGE tank though! 48 gallons? Do you really need that much water? That's close to 400lbs with the weight of the tank, pump, etc.

Also, with a 54" tank, you'll want to make sure it's baffled, as sloshing of that volume of water will really affect the rig.

As far as under vehicle - you'll want to have a plan for "winterizing" - include a drain and a give yourself a process for using RV water tank antifreeze so you don't freeze up the system and cause a problem. Otherwise, I'd say you'll be fine.

Personally, we get by with 12 gallons for short trips. I'd go as much as 15 or 20 if I was going long-haul, but nearly 50 gallons is WAY too much for me to haul around.

 

[cparcell]

Sorry typo, 24 inch. I can literally slide roto pax 4 gallons under the body. But I would prefer a single tank for the 20 gallon neighborhood. I'll consider that 200 lbs target as a good reason for purchasing hybrid bumpers like I did.

 

[cparcell]

I did consider a front runner footwell tank but at half the target volume and taking up interior space I'm hesitant to pull the trigger. The space under the body is essentially wasted unless I find handy things to stuff in it. I considered our camp table under it, possible chair storage etc but I would prefer to slide the table under the roof rack and chairs on top as light weight items

 

[TeriAnn]

So for the last 3 MO I have kinda had cross feelings about our 3 inch body lift, custom 3 inch body lift custom bumpers and the tall height of a xterra on a 3 inch suspension lift and 34 inch tires.

Let me see if I got what you said right: 3 inch body lift + 3 inch suspension lift + taller than stock tyres??? About 7+ inches of total lift? Please tell me I misunderstood.

We can talk about tanks when I figure out how high the vehicle is lifted and what type(s) of lift.

It is always good to put your heavy stuff as low as possible above the bottom of the frame rail but there is a right way and a wrong way to go about it. My truck as a 15 callon stainless steel tank at frame level.

 

[cparcell]

Yes 3 inch body my suspension is adjustable up to 3 inch lift and the 34s clear at around 2 inches in full flex. In actuality the tires are 3 inches taller than stock

 

[cparcell]

It's not as aggressive as you would think, I'll try to dig up a pic for you,

 

[cparcell]

With the lift and no basket on stock roof rack we sit 80 inches high, running stock SC 17 inch rims, the body lift did not affect the ride or roll, the suspension modification actually improved the ride quality and roll as uprated shocks and heavier springs paired with the load range e rides wonderfully, we are packed at 4500lbs currently. Looking to level out with complete vehicle ready at 5k. We sleeping inside with hardigg boxes that slide in on the sleeping platform and are easily removed for sleeping arrangement. Addicted off road tube front bumper, tube rock sliders and a hard core off road rear bumper. Rear swing out spare tire mount with high lift. I'll be adding fuel cans to the back. The engine performance modifications are extensive but our v6 puts most lsx engines to shame. Fully loaded on flat land we push 22mpg and 18 climbing hills on the highway. Currently we have the SC differential gearing which I'm debating to swap for a lot lower na gearing. My Stay at home wife dailys it for her soccer mom status. It's meticulously maintained, that's why we always drive it as a vehicle in motion stays in motion.


So with a basic break down, I think adding 200 lbs of water to the frame area with hardly affect it. But I was looking for any insight why it's a bad idea.

 

[TeriAnn]

OK. I think Herbie's concerns are right on though I always prefer a little more water than I actually need. I like to carry a couple gallon emergency stash separate from my drinking water system.

My custom made 15 gallon water tank is primarily vertical and the water doesn't have that much room to slosh. You are talking about a tank shaped more like a pool table. A tank with a lot of horizontal space to move in water in. The water going from one side to the other in a partially filled tank will be moving a lot of weight back and fourth. This can noticeably affect the vehicle centre of gravity and it will be a little slower than the way the centre of gravity moves as your vehicle turns, accelerates, decelerates, and handles slopes. You might feel it as a second push right after the first, If your vehicle center of gravity line (vehicle center of gravity point to center of earth gravity) shifts outside your vehicle's gravitational wheelbase (The wheelbase the center of the earth would see when the vehicle is tilted. Same as the shadow under the vehicle at noon) your vehicle will fall over. As your vehicle tilts on a slope, momentum and suspension sway will move the center of gravity line towards your wheelbase. If the momentum of gallons of water flowing from one side of the tank to the other hits before the vehicle center of gravity can shift back to a static position it will push the center of gravity over even farther. So as Herbie mentioned any horizontal tank that large needs to have rows of baffles going lengthwise vehicle front to rear and it wouldn't hurt to have one or two going side to side. Maybe with a 3/8 inch hole every foot or so along the baffles. You want the water to be able to flow, just slowly.

You will need to have a bottom facing drain plug at one corner of the tank so you can completely drain it by parking at an angle. And you are going to have to give some thought to where you place the pickup tube. With the shape of tank you are talking about you could have a quarter of a tank of water and still have the pickup out of water.

I sleep in a pull out cot bed inside the vehicle with my head towards the vehicle front. So I tend to camp with the vehicle's nose slightly elevated and the left side slightly lower (my bed is on the left side) so that gravity helps keep me in the bed which is almost five feet above the floor. If I had your style tank I would place the filler tube at the left rear corner. To make proper use of your shaped tank you will need a corner pickup tube and you are going to have to make sure you camp with that corner a little low.

About care and feeding of the water tank. Your tank shape puts a lot of the water next to the surface of the tank. That means it will freeze easily. You do not want to have a full water tank freeze. A partial tank can freeze without distorting the tank. When I'm camping and I'm expecting the night to drop well below freezing I fill my tea kettle and draw any water I might need in the morning before turning in.

You will want a white water hose with blue stripe to carry along for a filling hose. These hoses are made with drinking water safe materials. You can even get an inline charcoal canister to place between your hose and tank filler.

Key to maintaining a built in water tank is to periodically sanitize the interior to kill off anything that may want to grow inside. You can go to an RV store and buy sanitizing solutions or you can make your own. One tablespoon of unscented bleach per one gallon of water does the job. I live in an area where the lows reach below freezing for what seems like about half the year so keep the tank empty except when going out on trips. When I'm getting ready to head out on a trip I first sanitize the tank filling it with a bleach solution, driving around a little then draining the tank. I follow that up with drinking water. If I am constantly keeping water in the tank I like to go through the sanitizing step once every couple of months. If I'm going to keep the tank empty for a while I will drain it, sanitize it then drain it again so that any moisture left inside will have a minimum of bacteria.

You are talking about a very large volume of water. As Herbie asked how much do your really need in between stops where you can top off your water tank. In an arid region two people can usually easily get by with 5 gallons per day including cooking and cleaning. Camping with just my dog I can usually get a week out of my 15 gallon tank. If you do not need all that water you might consider one narrower tank down the middle or two narrow tanks one on each side to balance the weight.

You found a very good space, figure out how much water you need to carry then build tank(s) that will meet your needs and keep water from sloshing in wide open spaces Then keep the inside clean.

 

[Ducky's Dad]

You might want to consider fabricating a tank from parallel lengths of ABS or PVC pipe, connected with Ts at one or both ends. That would allow you to fit the length and width of the space you have available. ABS can take the occasional thump from rocks and tree stumps better than PVC and does not require any protective outer coating (i.e., paint). You can control sloshing by loading the pipe with wiffle balls, similar to what tanker trucks use on a larger scale. I have an 18+ gallon PVC pipe tank on the roof rack of my truck, and it's just too heavy up there, so I'm going to build a lighter version at about 12-13 gallons, still mounted to the rack.

 

[cparcell]

I considered abs and pvc but since the area is shaped I'm a rectangle it's a lot of wasted space for round pipe. The freezing fear although real isn't a top concern for me, our travel is mostly I'm spring summer and fall. Drain will be placed at the rear. Simply pull onto blocks and drain.
The slosh was a concern and baffles can be inserted easily, it was a reason I considered roto packs instead. A simple sump with a pump setup feeding through a valve for supply and refill similar to a external boat water fill and supply.
I also considered running 3 small tanks welded together with feeds on the side linking them.

 

[Ozarker]

Check out PEX tubing/pipe, 1 inch might wind all over the place with fasteners, very easy to work with, it can also connect other smaller tanks and may eliminate any sloshing and quick weight transfer. PEX won't freeze and bust, it swells up like a balloon then goes back to its original shape. I'm thinking of getting about 6 gallons on the roof, solar heated, a loop system can also be employed, naturally or with a pump, or tap off and use a pump for cold, hot water will flow will down. Might check out water bags too.

 

[cparcell]

I have a lot of experience with pex and although it's good it would seem as its a huge waste of space under the vehicle. Pex would work amazing for a solar heater since it will provide a large surface area. The transfer of heat isn't the best bit superior to pvc pipe and doesn't deform as much. The issue is that if you build a block section out of pex you end up with a lot of connections with the possibility to leak. Pex also I'd extremely flexible so it will need a substructure.

 

[Dan Grec]

I put a 12gal tank under my JK Wrangler. I have a Shurflow pump and 0.5 micron filter with UV treatment built in.
It also has a digital depth gauge so I know how full it is, and can watch as I'm filling it up to see when it's about to overflow.

I'm writing up a "DIY How-to" article on the whole thing now, should be online in a week or so, keep your eyes on theroadchoseme.com

For now, these are the best photos I have: http://theroadchoseme.com/jeep-build-phase-2-complete

(yes, it has a skid plate)

It's been absolutely fantastic so far, and was full of water when I ran Hell's Revenge in Moab a few days ago

-Dan

 

[cparcell]

Where did you buy your tank. And this is exactly like I was talking about