Angle grinding

No. But that's just me :)

I might if it were leaking. Otherwise not. Mike.

Nope, I wouldnt. Might find a sheet of metal to use as a little shield though.

I would fill it up to the top. A full tank contains no air, even if you take the cap off and set light to it it just flickers like a candle. An empty one goes BOOM! An empty one thats been washed out well still can. You can weld patches on a full one if you are daft enough. (Dont burn a hole through it though...)

WHAT THE F*CK FOR?

The fuel tank is the least of your worries. You need to snap a brake pipe and drain the fluid. At the scrappies I worked at, they set two cars alight using an angle grinder on brake pipes. The cars went up VERY quickly too.

Brake fluid is flammable.

That was a test to see how long it would take somebody to point out the obvious flaw in my plan *cough*. I'll have to go with a mini hacksaw instead, which is probably more sensible for a number of reasons.

Surely you can just mangle brake pipe up easily with a pair of side snips?

They need to be cut at the unions. No point snipping the pipes then leaving the unions on the car!

I take it penetrating oil and a spanner won't move them?

What unions are these? You'd normally just cut through the pipes. You can do this with a pair of small bolt cutters or hacksaw in seconds.

No, nor will locking pliers. See the "brake pipe hell" thread.

How are the unions attached to the car?

Where the metal pipes screw into the rubber hose fittings. I don't see how cutting the pipes will help me.

Um, each union being two parts, one the bolt on the fixed pipe, and the other being the nut in the rubber pipe, the two parts are screwed together with a chassis bracket between them. As I can't unscrew the unions with the pipe attached, I won't be able to unscrew them with the pipe snipped.

I'm sure you know that, and are trying to get me to realise that I can't see the forest for the trees.

Right. Can you slacken the locking nuts on the hose fittings? If so cut through the hose thread as well as the pipe.

Was this some time ago? It's not on my newsreader - perhaps it has expired it?

You mean mole grips? Course they won't - wrong tool for the job.

Because it'll allow you to get a hex socket on it which will give a better grip and undo them. Worked for me on 20 year old brake pipes on my Capri.

But then again, I recall you mashed them up with molegrips?