rust on tank

[miggs]

right i have got my petrol tank out and want to give it a lick of paint but the top is quite rusty how long will i have to wait before i can wack a flap disc on the grinder over it or is it best to put water in etc

[colinthefox]

You must fill it right up with water leaving no voids. Fumes will hang around for ages.

[California Dreamin]

I'm not sure I would want to be filling it up with water if I was going to re-use it.
Whilst every care must be taken to avoid an explosion from the petrol vapour I would be much more inclined to rinse it out with something much less volatile but less problematic than 'water'.
Diesel perhaps....rinse out several times (a gallon of diesel each time) then seal the tank and do your cleaning up.
As a bonus...the diesel should be perfectly useable given the extreme dilution....but pass it through some cloth to remove any bits.

Use a method of cleaning that doesn't create sparks.

Martin

[kevtherev]

wire brush the loose stuff off and use hammerite
once sealed in the rust won't get any worse, as it's deprived of oxygen.

[Hacksawbob]

just a thought, flush with CO2? fire extinguisher, attach a hose, moll grips on the handle set it to a trickle.

[Plasticman]

you call it a petrol tank! but is your van petrol or diesel,? if latter then it wont go pop, that said I wouldnt bother with a disc, do as others have suggested and half kill it with a wire brush
mm

[miggs]

its a petrol better get the wire brush out cheers peeps