Boat gas tank on roof?

[HenryKrinkle]

Hey guys, new here and looking for some tips on using an old 12-15 gal boat tank for my XJ. I've found a few on craigslist for pretty cheap. They are the type that are about 40"x7"x20" with the fill caps on the top so they lay flat and low. I'm wondering if anybody can help me with some mounting/usage tips. Should the tank be grounded to the body? Could my factory roof rack support the weight? I'm planning on picking one up, cleaning it out, maybe painting it, then figuring out how to mount it on the roof. I wouldn't keep it up there, just throw it on top when it's needed.
Anybody do this before? My main concern is the grounding issue and the security of the factory rack. I may spring for JCR gutter mounts if I have to (or just in the future for peace of mind).
Thanks for any help...

 

[CA-RJ]

A gas tank on your roof? That sounds dangerous. You're adding weight up top...weight that moves side to side. That's going to create a roll over hazzard. Also, what happens if you get in an accident and roll over? Fire hazzard as well?

 

[getout]

I don't think it's good idea, but continuing this line of thought, what about a real slim fuel cell?

 

[R_Lefebvre]

FWIW, the purist Land Rover owners love their gas tanks on the roof. No worries about CG or rollovers or anything.

 

[getout]

FWIW, the purist Land Rover owners love their gas tanks on the roof. No worries about CG or rollovers or anything.

That's really funny that I didn't even think of that. Tons of expo rigs run cans on top. This would be the same thing, only permanent. Run a hose out the side to your tank and gravity would fill it up.

The only problem I see now is having to get on your roof to fill your tank at the gas station might cause some concern.

 

[Terawanderer]

First fill several 5 gal cheap cans and bring them home. Now fill your boat tank on the roof from them. Drive extra carefully until you get to the off road area. Get out and drain as much gas as you can into your vehicle. If you start with 15 gallons(90 lbs) and drain out 10.....you have a mere 30 lbs of fuel on top. Not much rollover danger. Grounding it is a good idea....but I know a guy who uses a 6 gal boat plastic container on top of his Nissan Exterra with no problems ....and no grounding.......

 

[bloc]

Multiple cans on the roof is only a comparison here when the vehicle is not moving.

Without any form of baffle inside that thing, if it is anything but full, empty, or very close to empty, you will have weight shifting around in probably the very worst place you'd want it. Any quick stops, turns, or shifts in vehicle level would become... interesting.

If you must put fuel on the roof please use smaller cans. A couple good jerry cans should only be ~$40 each from surplus

 

[peekay]

you may be right if he was considering a 50 gallon+ tank. But he's looking at a 12-15 gallon tank. That's maybe 50-60lbs at most, and only when the tank is full (which is when there are minimal weight shifting effects).

 

[TangoBlue]

Water weighs 8.3 lbs/gal, gasoline weight is 6.2 lbs/gal at 72*. So 12 gal would be 74.4 lbs and 15 gal would be 93 lbs; now add the weight of the tank and accessories/mounting hardware.

Make sure you have a well mounted roof rack and let us know where you are wheeling so we can bring the appropriate equipment to record your trip. :yikes::campfire:

 

[Mr. Leary]

I have sturdy plastic boat tanks with top fill. The shifting weight is always a concern, as is sunlight making the tank brittle over time. If it only goes up there for trips, however, I say go for it... it can't make your truck much more unstable than a 150lb. RTT. When considering other options, it may be the lesser of the weavels.

 

[Layonnn]

FWIW, the purist Land Rover owners love their gas tanks on the roof. No worries about CG or rollovers or anything.

True, But unless the marine gas tanks have baffles, you have to worry about sloshing.

Also, about the only thing you can use to fill it up with is a super siphon or a hand pump. Also, removal once filled up will be a hassle due to the weight of it seeing as how most of them would be more than a 5 gallon like Jerry cans are (really 20L).

 

[4Rescue]

I do it...I have a red plastic tank I run in my basket on long trips cdause really it's not that much weight up there and I can gravity fill my truck with it... I think it's great. Do I go trail riding with it like that...no, but for long drives and trips out to the Alvrod it's a great,cheap set-up. Not really any different then having Jerry cans up there, and I'd imagine more rigs get hit in the back then roll over all in all so wouldn't having it be on the back rack like most folks run be "most dangerous of all" ???

Cheers

Dave

 

[R_Lefebvre]

That's really funny that I didn't even think of that. Tons of expo rigs run cans on top. This would be the same thing, only permanent. Run a hose out the side to your tank and gravity would fill it up.

The only problem I see now is having to get on your roof to fill your tank at the gas station might cause some concern.

I've seen lots of people filling jerry cans while they're still on the roof. I dunno.

I guess the sloshing is a potential problem. It would be minimized if the tank were positioned long way fore-aft.

 

[HenryKrinkle]

Well, it seems some people think it's a really bad idea. The tank I'm looking at is 36x18x7. It's not really that big; as long as I can attach it well I don't think it would be a big deal. It's not something I'd use everyday. I'm thinking I'd make the mounting setup and then just keep it all in the garage until I need it.

How many people run overbuilt steel racks with tents, jerry cans, spare tires, etc. up there?


I could just get jerry cans, but then they'd have to be stored upright which means they'll probably have to go into a special mounting bracket on the rear bumper= expensive. Also, I wouldn't want fuel permanently attached to the most likely place of getting hit (large metro. area).

So for $40 I'm going to give it a shot. Once I get it mounted and full I'll take it for a spin, if it seems dangerous I'll go for something else. I guess I'll keep you posted...

 

[Albin]

Good, one test is worth a thousand theories. Got a link to the tank?

Let us know how it goes. Good luck.

Al