Brazing/soldering a fuel tank

[chrisdcapri]

I need to change the fuel feed location in a fuel tank. I was going to put a metal fuel line in and seal it, but does it need to be brazed, silver soldered or what? any ideas?

[bortaf]

Normal solder cracks, never silver solderd a tank pipe before i allways get them braized now.

[Ratdat]

I braze stuff like that.

[optima21]

or if its a steel pipe into a tank, can you weld it.

[composimmonite]

Most traditional radiator repair places will be able to change feed location. Not sure how / what they do though. Personally I'd braze but reckon silver solder would be just as good albeit more expensive for materials.

Paul H

[bl1300]

Id be a bit worried about the safety implications of naked flames near fuel tanks. Id flush it out several times and have it full of water when you start brazing/soldering. Oh and wear goggles and keep a fire extinguisher handy.

[barty]

seek out an expert if welding/soldering fuel tanks, a fire extinguiser could be handy but not much good if it explodes lol. oh and you wont be able to solder if it full of water either. Ive heard you could fill it with sand but to be honest send it to someone who knows what they are doing.
I had to add a return pipe to a mk1 escort tank once and i just took the sender out and soldered a pipe into the big flange which is part of the sender unit, there was plenty of room and you can take the sender out to work on it

[Ratdat]

All you need to do is make sure it's empty and dry (leave it open in a warm place for a few days). You can then purge vapour from a tank whilst welding/brazing using a C02 fire extinguisher.

[goldnrust]

Due to reading lots of horror stories about exploding tanks, when I needed to fit a new return line to my take I soldered my new return line onto a piece of steel, contoured to fit the tank. Then drilled a new hole in the tank top and then bonded my new steel to the tank. That way I had a decent surface area for the epxoy to stick to and the new line was brazed in so held secure

Like this....

[bortaf]

I do love it when fuel tanks ccome up in discussion sand LOL

[Dez]

Nov 30, 2011 16:02:13 GMT goldnrust said:

Due to reading lots of horror stories about exploding tanks, when I needed to fit a new return line to my take I soldered my new return line onto a piece of steel, contoured to fit the tank. Then drilled a new hole in the tank top and then bonded my new steel to the tank. That way I had a decent surface area for the epxoy to stick to and the new line was brazed in so held secure

Like this....

really? that looks wibblepoo.
rather you than me.


i cut and weld fuel tanks regularly. i modded a scimitar tank to fit a pilgrim kit car only last week- change of filler neck, cut hole for new one and weld in a pipe stub, plate over old hole, and them weld on 4x new brackets. all without incident. just fill up with water, then cut with the bit your working on at the highest point.
its not about 'purging' or getting any residue out, its about hot having a large empty vessel full of air for the explosion to be contained in if it does go- small volume=less air=less oxygen=smaller/no bang when the vapours do ignite.

[Mystery Machine]

We've cut open several fuel tanks, some with petrol still in them and you really have to work at it to make them ignite! It's not the 'death to everything within 50 yds' some people might have you believe. Just use common sense.

It's not the petrol itself you need to worry about, it's the vapours (as Dez says). I usually chuck a lit match in from a distance - you get an initial flash then I let it burn off for a bit. Blow it out (if it hasn't burnt itself out) then off you go.....

Never had a problem. (photos to prove as well if needed??)

[Mystery Machine]

Oh...and sand? Really??

So you're 100% that you'll get it all out? All the residue you can't get out is gonna do your filter/engine/pipes/pump etc... the world of good when it get sucked up from the tank. LOL.

[Ratdat]

Ultimately, there's lots of ways of going about it. A tank that's easily drained I'd fill with water (like I did with the one on my Pony) but it isn't ideal with all tanks. My Renault 30 tank was an absolute mare to remove the water from after I repaired that. No amount of shaking, blowing or heating would empty or dry it.

Regardless, it's purely a matter of making sure there's no vapour to go pop in any kind of quantity. Same deal as cutting a gas cylinder to make a wood burner.

[goldnrust]

Nov 30, 2011 22:56:36 GMT Dez said:

really? that looks wibblepoo.
rather you than me.

I'm not saying the execution was elegant, certainly I've little soldering experience and my support for the new return to stop it snapping off like the old one again isn't elegant.

But the method of creating a larger contact patch for epoxys to stick to is sound. I still wasn't happy welding a rotten 30 year old tank.

Each to their own and all

[adamwatson]

I've welded loads of petrol tanks, always just washed them out with truck wash and got on with it. Never welded while it was full of water or anything like that, never had one explode. Only other advice I have is to get some dye penetrant to test it with after, saves having to do it all over again if it leaks

Adam

[curryracer]

Dez / Adam
Was this MIG or TIG welding for the tanks ? ?

[xbo11ox]

I recently had to weld up a nuclear warhead for a Russian guy who lives down my street, I just left it out in the garden to air off for a few days before welding it. I am pleased to report the job went smoothly, would defo do another one if he finds any more.

[adamwatson]

Dec 1, 2011 21:54:42 GMT curryracer said:

Dez / Adam
Was this MIG or TIG welding for the tanks ? ?

Tig, most of the tanks we had to weld up where I worked were ally but even if they were steel I'd of tig'd them

[chairchild]

Dec 2, 2011 12:40:12 GMT xbo11ox said:

I recently had to weld up a nuclear warhead for a Russian guy who lives down my street, I just left it out in the garden to air off for a few days before welding it. I am pleased to report the job went smoothly, would defo do another one if he finds any more.

did you fill it with sand before welding it? And I'll assume it was gasless wire, on rusty, oilly metal? This obviously, gives the best welds