Using body filler.

[ducatilover]

Precisely the problem. I want a way to boof the dent without having to weld things to the tank (especially if it's a chrome plated tank !)

There must be a better way.

Magic wand? I don't think a suction cup would work well enough...How many PSI can you get from your compressor? [assuming you have one good sir Ixion]

[motorbyclist]

I have seen tanks left for weeks full with soapy water welded and explode. But I know of people who keep the tank full of gas [to the top] so there are no vapors and they still have their faces

how can an open tank full of water possibly explode? this concerns me greatly.

if you empty it then of course it's going to explode as the vapours enter back in from the seam where the two halves are welded together

Precisely the problem. I want a way to boof the dent without having to weld things to the tank (especially if it's a chrome plated tank !)

There must be a better way.

giant magnets?

strong language? (we've all tried it)

[Ixion]

Yith I have a compressor which can easily enough reach 120psi. But that is no solution because it will certainly distort the tank in other areas. I want it still to be a petrol tank at the end, not a beach ball.

I think the answer is still to push it out from the inside. What is needed is some sort of hydraulic how's y' father that can be inserted into the fille oriface , positioned over the dent , clamped in place, with the tank also clamped, and then pumped to push the dent out.

Generally it doesn't need a lot of force to dedent a tank, it's not like straightening a car chassis. Just needs the force applied in the right place.

The principle's simple enough it just needs somebody like Sykes to develop the little hydraulic rammy thing.

Alternatively, a very small panel beater who can climb inside the tank and bsh the dent out with a little hammer.

[Ixion]

how can an open tank full of water possibly explode? this concerns me greatly.

..

Vapour lock. A "bubble" of petrolly air trapped inside in a crevice of the tank. Just think how hard it is to get all the air bubbles out of a hydraulic systenm when you bleed it. And a tank has lots more blind spots and dead ends than a brake system.

[ducatilover]

how can an open tank full of water possibly explode? this concerns me greatly.

if you empty it then of course it's going to explode as the vapours enter back in from the seam where the two halves are welded together



giant magnets?

strong language? (we've all tried it)

See Ixions post below...

Vapour lock. A "bubble" of petrolly air trapped inside in a crevice of the tank. Just think how hard it is to get all the air bubbles out of a hydraulic systenm when you bleed it. And a tank has lots more blind spots and dead ends than a brake system.

I like your hydraulic ram idea, but, I think the steel will have stretched and you will still be left with minor ripples. [not nipples]

[Owl]

There are some dickheads around here.

That's not very nice!

[wbks]

Vapour lock. A "bubble" of petrolly air trapped inside in a crevice of the tank. Just think how hard it is to get all the air bubbles out of a hydraulic systenm when you bleed it. And a tank has lots more blind spots and dead ends than a brake system.

Yes, and what happens when explosions happen under under water?... Think I'll just fill the dent up in layers

[kevfromcoro]

Jesus.. dont put a flame near the tank. espesially if its empty.
If you can seal it off. get hold of a low pressure reg. stick about 3 0r 4 psi in it and you will find it will pop out.. doesnt take much..
just dont put to much pressure in it.... or you will end up with a fat tank

[LBD]

Beer and an office job....worked wonders for the ripples and dents I had around my tank...is now nice round and smooth.....

Crack open another 6 pack...?

[The Stranger:Me]

A Slide hammer can be useful here but if you do anything involving heat be sure to purge the tank fully!

How do you "purge the tank fully"?
I have welded a used car fuel tank before, but it handn't been used for some time. I washed it out with water and (on the advice of a panelbeater) ran a car exhaust into it for a while before and whilst I welded.
I'm still alive, however that may just be luck.

[The Stranger:Me]

I would but I can't bang it out myself and I'd rather use this old tin of body filler that's getting no use, than pay for someone with the tools to do it. I mean, even if I did push it out, wouldn't you still need to use a bit of filler to cover the creases?

Water expands about 5% when it freezes, but yes you will still have creases.

[LBD]

How do you "purge the tank fully"?
I have welded a used car fuel tank before, but it handn't been used for some time. I washed it out with water and (on the advice of a panelbeater) ran a car exhaust into it for a while before and whilst I welded.
I'm still alive, however that may just be luck.

Remove all fittings, valves fuel pulmps filler adapters etc, where fuel remenants may be lurking....wash out with warm water and detergent, when dry tape up openings and use an inert gas to purge the tank, and keep a slow flow of inert gas into the tank while the hot work is done....

[The Stranger:Me]

Remove all fittings, valves fuel pulmps filler adapters etc, where fuel remenants may be lurking....wash out with warm water and detergent, when dry tape up openings and use an inert gas to purge the tank, and keep a slow flow of inert gas into the tank while the hot work is done....

Carbon monoxide will do it then?

[LBD]

Carbon monoxide will do it then?

CO would, if it was pure without any free oxygen....not sure if I would trust exhaust gas....Also may be from a rich running engine with some unburnt fuel in the exhaust gasses....

Argon, CO2 from an extingusher, nitrogen etc...

Done it many time but then I have always had welding gasses on hand....

[koba]

Carbon monoxide will do it then?

How do you "purge the tank fully"?
I have welded a used car fuel tank before, but it handn't been used for some time. I washed it out with water and (on the advice of a panelbeater) ran a car exhaust into it for a while before and whilst I welded.
I'm still alive, however that may just be luck.

I think there is a thread to two on this. I've sucessfully used exhaust gasses with a warm engine and the idle mix leaned out.