Tank storage

What is the best way to store a fuel tank for a few years?

Possibly the best way is to remove all the fuel, insert several nuts on a wire and shake them all about, rinse out and leave out in the sun to dry out completely for a few days, depending on where you live.
Then pour some 2 stroke oil, or a whole bottle of Redex into the tank and swirl it about into every corner.
Clean up the paint work with colour back, then give a least 2 coats of wax, allowing to dry in-between coats, and cover with a thick cotton cloth, like an old towel.
But store in a dry moist free place. A non -centrally heated garage that suffers a lot of condensation is no good.

is that the same for metal and GRP?

And re-commission is a reversal of the procedure I guess?

I didn't do anything to my F/G tank for the last 20 years other than take the fuel out of it. But of course all I put in it now is avgas.

Dave
69S