Fuel tanks

[lambeth]

Apologies if this is posted in the wrong section but it is about fuel tanks so general gassing seemed appropriate.
I am in the process of an underside restoration of my car and decided to replace the fuel tank as the old one looked a bit tired. However after I bought a smart secondhand tank (at great expense) and then removed the original it revealed on closer inspection to be in good shape and only cosmetically challenged. It turns out that I was very lucky to find a good second hand tank as they are now almost unobtanium. Therefore I want to keep the old tank (just in case) but how do I keep the exposed inside in good nick as the fuel pumps are not installed and the large openings have revealed the interior as looking like shiny raw steel which I don’t want to rust.

[Krikkit]

There may be other ways, but this would be the most complete:

https://www.frost.co.uk/por15-basic-big-fuel-car-t...

Seen it used to rescue very corroded and damaged bike fuel tanks.

How dry is your storage?

[neutral 3]

Pour in some two stroke oil mixed in petrol and slosh it thoroughly around. Could also use Diesel.

[lambeth]

Thank you both for the responses - I will go with the POR products from Frost as they seem to have good reviews