Patching Leaking Fuel Tank • The Dodge Challenger Message Board

by **Jon** » 15 Feb 2010 4:30

The old Massey Ferguson tractor is leaking diesel and I am wondered about a safe way to weld the tank. What rinse or other solution would be used for this.?

by **redgum78** » 15 Feb 2010 7:18

Hey Jon.

I have seen this done with several methods and different degrees of success. I know of one fellow who blew himself up and ended up in hospital (it was a diesel tank too, it can be just as dangerous as petrol under the right conditions), so please proceed with caution. :shock:

Personally I don't think any amount of flushing or rinsing makes a fuel tank safe to weld. In the oil and gas industry they normally use one of the following methods for welding vessels, pipes, spools, etc.

The best option is either displacement or continuous purging.

If the tank can be COMPLETLY filled with water (displacement method) and welded (while full) that should be ok but lots of flushing will be required to avoid water in the diesel when you put it back in service.

If the nature of the repair prevents filling with water a continuous purge could be used. The best thing for continuous purging is N2(nitrogen).
I have heard of people using a running car exhaust for this but have not seen it done 1st hand. The key is to purge out any O2 and thus removing one of the 3 elements required for fire/explosion, ignition, fuel & O2. The problem with purging is that it needs to be maintained during the welding operation and it is hard to measure how well it is working without an O2 meter.
Either method you should still rinse the tank with a non flammable solvent 1st.

Myself I would remove the tank, rinse it several times then fill it with water (making sure there is no trapped air pockets) and maintain it full while welding. It has worked twice for me.

Hope this helpsl.

by **ianandjess** » 15 Feb 2010 13:15

when i repaired the seem on the tank on my challenger i drained it the left it in the sun for a day or so then filled it with water & welded it while full & i had no problems
cheers ian

by **dave-r** » 15 Feb 2010 13:34

You can have so much fun doing this type of welding. :roll:

I blew up a gas tank once myself. I had ran water through it for an hour or so but didn't think it would gas weld with water still in and leaking out. But when I passed the torch over the inlet to test it blew wide open and I nearly soiled my pants. :lol:

My mate welded the sump on my 318 once while it was still on the engine and blew it up. :lol:

Actually the sump was OK. In fact the dents in it vanished. :lol:

But every gasket on the block was blown and needed replacing along with several core plugs.

I pulled my mate out from under the car by his feet because he didn't respond to my shouts of "Are you OK?".
In fact he was OK. Just a little deaf. And he looked just like Al Jolson. :lol2:

by **Eddie** » 15 Feb 2010 14:49

dave-r wrote:You can have so much fun doing this type of welding.

I blew up a gas tank once myself. I had ran water through it for an hour or so but didn't think it would gas weld with water still in and leaking out. But when I passed the torch over the inlet to test it blew wide open and I nearly soiled my pants.

My mate welded the sump on my 318 once while it was still on the engine and blew it up.

Actually the sump was OK. In fact the dents in it vanished.

But every gasket on the block was blown and needed replacing along with several core plugs.

I pulled my mate out from under the car by his feet because he didn't respond to my shouts of "Are you OK?".
In fact he was OK. Just a little deaf. And he looked just like Al Jolson.

by **Jon** » 15 Feb 2010 15:08

Thanks for the comments guys. I think it best to leave to a pro or just get a new one. My welding isn't very good anyways. :s022:

by **dave-r** » 15 Feb 2010 15:10

Hope I didn't put you off.

I still have all my fingers and everything. :thumbsup:

by **RedRaven** » 15 Feb 2010 15:46

One of Daves Beano comic moments haha. :lol:

by **redgum78** » 15 Feb 2010 21:56

dave-r wrote:You can have so much fun doing this type of welding.

I blew up a gas tank once myself. I had ran water through it for an hour or so but didn't think it would gas weld with water still in and leaking out. But when I passed the torch over the inlet to test it blew wide open and I nearly soiled my pants.

My mate welded the sump on my 318 once while it was still on the engine and blew it up.

Actually the sump was OK. In fact the dents in it vanished.

But every gasket on the block was blown and needed replacing along with several core plugs.

I pulled my mate out from under the car by his feet because he didn't respond to my shouts of "Are you OK?".
In fact he was OK. Just a little deaf. And he looked just like Al Jolson.

I did the same thing when I was about 20. I was trying to repaire a sump on a Mack truck (16ltr V8 diesel). It Blew the valve covers of the engine and bulged out the sump :shock:

by **Moparman1972** » 16 Feb 2010 1:08

My father welds Harley tanks all the time. He rinses the hell out of them, leaves them sit for a day with water in them, rinses again, drops several matches in. He probably does a set a month.

He's still had 2 tanks ignite while welding. No ruptures, but they try to turn themselves into basketballs. It's very dangerous. And that's just a small 3 or 5 gallon tank.

by **Jon** » 16 Feb 2010 2:51

Don't get me going guys, I'm cheap enough to actually try welding on it to save a buck. :lol:

by **patrick** » 16 Feb 2010 4:51

JB Weld is a good patch until you get a good or, new tank. Usually when you need to weld the tank, it has several other problems. Just my two cents worth. :wink2:

by **Jon** » 16 Feb 2010 14:58

Yes Pat, I did the JB weld and it held for a little while. The patch on the radiator is still holding strong though.

by **fbernard** » 17 Feb 2010 9:42

You can also use chemicals like this :

http://www.restom.net/kit-traitement-de ... ir-150.htm

(the link is in French, but I'm sure chemicals like this exist in a more English-friendly version... :s009:

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