21 replies to this topic

[Alex_B]

If you are welding on a tank, make sure it is completely flushed out, *do not take this advice as gold, just my experience*

I have welded on a mini tank, moved the neck into the boot, was on a non road legal mini at my old college so wasnt bothered by laws, basically cut a square out around the neck, and a same sized square on the otherside of the tank, but I had flushed this tank out about 10 times, and was still paranoid, but carried on and it was fine but I could have lost my eyebrows!

and someone else did what I did but did end up crapping himself and running across the workshop as he filled it with water and drained once expected it to be fine and started to cut into the tank, sparked and it exploded a bit inside, was funny to watch but only because he wasnt hurt.

[tiger99]

There is a long history of people being killed, injured or just getting a big fright when trying to weld fuel tanks, and most of the accidents have not involved Minis. That is because, being in teh boot, the Mini tank tends not to rust, and many of the welding repairs in the past were to fix rust holes.

I am told that the professionals steam clean them thoroughly, and even then purge with nitrogen, CO2 or argon when welding. There is probably something on the HSE web site about how to do it safely and legally. If you are welding in the neck, you can indeed fill the tank with water, as the tiny volume of vapour in the neck should not present much risk. Personally, I would take it to a professional, with the correct tools, training and health and safety compliance. Almost everything else I would prefer to do myself, so I know it is done correctly (especially ball joints, steering column to rack joints and brake hydraulics, the three main killers on a Mini), and I often encourage people to learn to weld, because of the eventual necessity if you have a Mini, but I draw the line at fuel tank welding.

But don't let me put anyone off from doing it safely and legally, by following the proper procedures, if they really want to. Just please don't cut corners!

[Doz1971]

Many moons ago, I watched a guy at a track side welding a motorcycle tank. I enquired why it didn't go bang.

The gentleman in question showed me.

Empty the tank. Place the filler nozzle over the exhaust pipe of an petrol engine and rev the engine. He said that kills the vapour dead.

I've never tried it. This was in the days before catalytic converters, so I'm not sure it would work with a cat vehicle anyway...

[pympster]

Interested in the gauze idea for my friend, he has had to replace his fuel cap 5 times now!

[jaydee]

You should check the legality before applying most of the well-intentioned suggestions here. For a start, having the filler in the boot is very dangerous and most probably illegal.

Probably illegal as its a modification that probably require testing and subjected to approval, some other classics came out of the factory with a boot tank and they had the filler neck inside. One above all, the 500 had the tank filler in the trunk.

[DannyTip]

SPI/MPI tanks have a flap in the filler neck which may help but not remove the problem.

[zeroasylum]

SPI/MPI tanks have a flap in the filler neck which may help but not remove the problem.

Hi guys thanks for all the responses. Is the flap like that in a modern car tank and does anyone know where I could get one to fit my tank.

Thanks

Zeroasylum