TY175 fuel tank - internal clean

[Campy]

Hi all

I have recently bought a '76 TY175 that is a complete rough-runner but the main issue is that the fuel tank is very rusty internally.
It had been sitting in a guys shed for a while but still started easily.

Any recommendations on best way to clean the inside? I have got most of the loose stuff out with some gravel and petrol. Not game to put in the cement mixer just yet.

Happy to try Coke if I can get some on special and it is quicker and cleaner than molasses...

Not planning on lining it at this stage.

Here she is hiding behind my good TY:

[Gomey]

Fill with white vinegar for a few weeks. Wash out with Inox to stop flash rust.

[AndrewT]

Used Cole's Supermarket Double Strength White Vinegar on mine with a handful of mudguard washers -shook it around 2 or 3 times each day then emptied and filtered the vinegar every day with Scott towel over a funnel and refilled tank. Took the tap out and plugged it. Took about a week but very happy with results. Use Inox or similar to stop the flash rust when done. I refilled mine with oily 2 stroke once cleaned out and flushed

[Campy]

Thanks guys!
So once flushed I was going to rinse with isopropyl alcohol to get any water out then fill with premix. Do I need to use Inox before the fuel? How does this go with the fuel - no effects on running?