(Edited) I have a New tank now, Need advice on the resto work.

Whats the best way of cleaning up the underneath of the car?
I just wont to get rid of the suface rust and re-underseal. I thought on the lines of a wire brush but that would take ages

Cheers

 

try www.gmscaprispares.co.uk for petrol tank

think there about Ł120

 

Just buy a new one only Ł70 at allparts.

 

I got a new one for mine was getting rather shitty, cost me Ł80. To treat the underside first you need to get all the muck off. Use WD40 or petrol to remove all the road grime and then use a wire brush attachment for an electric drill to remove the surface rust.
Treat any rust then apply underseal or black waxoil, It’s also worth filling any box sections with waxoil while you’re under there

 

Cheers guys for the advice, got a new tank for Ł47 Bargin.

Also do you know if you can paint over the underseal/waxoil?

What's good to treat the rust with?

 

Treat the rust with jenolite rust remover, then coat with an etch primer, or
something like 182 zinc primer, then finaly sholts underseal,