Outer Limits 4x4 Board

I'm cutting my chassis short at the rear and will need to mod my fuel tank so it doesnt stick out past the chassis rails.

I've planned to cut the tank with a grinder and weld a sheet across the hole that's left. Will this work OK without warping the sheet i'm welding on? I cant think of a better way of doing it. The hole to be covered should be about 500x200, the tank looks to be made from about 2mm sheet, i was going to use the same to patch it.

Will be interesting to see if the sucker has got baffles in it, i'm thinking not. It's a aftermarket 70L tank for LWB zook.

STOP Damo Don't go any where a near that sucker with your grinder !!!!

Can't you fit the short wheelbase tank under there ? once you shorten it ?

I havn't seen the results of a tank cut gone wrong but my father told me once of watching a guy up in the top end ,cutting up 44 gallon drums ex fuel dump drums ,empty they where filling them with water first, and even after it had water in it it still went off like a grenade when he hit with the oxy what a mess----.

Let some other sucker do it !

i would have to agree with doozer, get a smaller SWB tank and sell the big one.


On a side note, an radiator shop will be able to cut it and braze it back together, leak and pressure test it sweet as.


NICK

SAFETY FIRST never ever bring a grinder near a fuel tank
Is the tank gonna be empty or what

Julian_4x4 wrote:SAFETY FIRST never ever bring a grinder near a fuel tank
Is the tank gonna be empty or what

now that you say it, i think it could be an LPG tank


NICK

Two ways to do the job..
wash liberally with water and detergent then....
secondly. vent a tube from a vehicles exhaust into the fuel cell..
this fills it with carbon dioxide and what have you thus rendering it inflammable. grind or cut away after several minutes.

Ka BOOM ! Leave it to the pros, you dont want to end up like this guy.

I've just left a little bit of fuel in the tank and swished it around so i can get some nice vapour happening. Just to make sure i think i'll fill it with acetylene as well...

Jeez guys, i'm not THAT fawkin stupid. I have already welded this tank once, had it full of water at the time. That might not be practical in this case though. I was going to drain it then run some water through it then let it air for a week or 2. Surely then it'll be OK.

I could use a SWB tank but dont have one to use. I dont really want to buy a tank when i already have this one. Even cut down this one will have more capacity than a stock tank. I doubt I would be able to mvoe this tank up here anyway coz it wont fit a SWB zook only a LWB (not even the LWB utes).

Thanks for the rad shop tip Nick. There is a good rad shop here, i'll hit them up about it.

you never know with some poeple but damo ,Just didn't want you to get cooked .

just for your info, the metal of the tank will actually absorb some of the fuel and washing it will not completly remove it all.. once the metal heats up you will find some nice flames or a big kaBOOM!!!

i wouldnt risk it...

Working in the Emergency Department of many big hospitals (as I do), I have seen on more than one occasion ('bout 2 this year alone) the results of people cutting into empty fuel tanks at home.

YES....these people did wash the tanks out with water

YES....these people did leave them sitting for a week or two (one bloke had left his for a couple of years sitting around outside empty)

YES..... these people did end up with 2nd degree burns to their face, chest, arms and one poor bastard breathed in at the wrong time.......and ended up having a machine do his breathing for him for a couple of weeks.


Listen to the above advice, and get someone else to do it that gets workcover if the thing blows in his face

Listen to the man who has seen when things go wrong, i will say no more on the subject.

let all the fuel evapourate away for a couple days, and then pump carbon monxide (car exhaust) through it as you work on it. Water doesn't work very well because the fuel that is left partially absorbed by the steel will repel the water and still burn. The carbon monoxide just won't let it ignite.

We got some pretty healthy discussion out of this topic.

I'm going to try to find someone locally that does work on fuel tanks and see how they do it. I'm interested to find out how the "pros" do it (not to mention having a strange interest in self preservation).

The radiator place here pumps freon? (I think) through them, they have a closed circuit setup, so it just keps recirculating the same gas, once all the air is out of the system.. Would hve to be done differently in your case though, pretty hard to have a closed circuit with a 500x200 hole in one end.

Yeah, that's what i was thinking when u guys started talking about exhaust gas

Maybe flick a match in the fuel filler just to be sure

That sounds like pretty sound advice Damo.


But what kind of sound? A big Ka Boom sound.

Like others have said - don't rely on washing it out and leaving for a few weeks. You were lucky before.

Even filling with water can leave some air pockets.

Exhaust gas is good, but don't stop until you finish cutting/welding.

Another method I saw on POR the other day is to half fill with water and add some lumps of dry ice (liquid CO2).

The dry ice one sounds like a pretty good idea.

Ferozius wrote:Working in the Emergency Department of many big hospitals (as I do), I have seen on more than one occasion ('bout 2 this year alone) the results of people cutting into empty fuel tanks at home.

YES....these people did wash the tanks out with water

YES....these people did leave them sitting for a week or two (one bloke had left his for a couple of years sitting around outside empty)

YES..... these people did end up with 2nd degree burns to their face, chest, arms and one poor bastard breathed in at the wrong time.......and ended up having a machine do his breathing for him for a couple of weeks.


Listen to the above advice, and get someone else to do it that gets workcover if the thing blows in his face

you most likely won't die!!! but it will hurt~~

I wish i had ginger pubes, they dont burn right BJ

Water wont work.
Draino is the answer. Essentially all the places who do it commercially use water then draino then water again. ( Provided theres no plastic parts in there.)

What's in draino that makes it work in this case?

No idea what the active part is, but it's strong.

There is only one safe way to do this. ( dont do it)
If you have to then the approved method is to use steam to purge the fumes from the tank as well as any fuel that has been absorbed.

This takes aprox 30 minuites.

Only then should you weld it.

GOOD luck.
regards
Michael.

Liam wrote:No idea what the active part is, but it's strong.

This'd be good for cleaning any crud out of the tank to i'd say.

HSV Rangie wrote:There is only one safe way to do this. ( dont do it)
If you have to then the approved method is to use steam to purge the fumes from the tank as well as any fuel that has been absorbed.

This takes aprox 30 minuites.

Only then should you weld it.

GOOD luck.
regards
Michael.

Hmmm, getting too many options now! If this works why do you say not to do it????

stop being a girl!

purge with carbon monoxide

Damo, this is the way they taught us to weld fuel tanks.

Most high pressure steam cleaners struggle.

Factory witha steam boiler is the go.

Michael.

HSV Rangie wrote:Damo, this is the way they taught us to weld fuel tanks.

Most high pressure steam cleaners struggle.

Factory witha steam boiler is the go.

Michael.

OK, so we're talking a LOT of steam.

Are we talking a sierra tank between the rails in front of the diff ?