gas tank h_elp needed!

[James Weiler]

Hello everybody

Anybody got any advice on how to clean up some rust from the inside of a 
steel gas tank?  It's out of a '69 Cougar so it's old but I live in a 
salt free evironment and it passes the screw driver test easily.  Th e 
rust inside I believe is just surface and could be cleaned with sand 
paper but of course I can't get in there.  I have phosphoric acid which I 
will try (I've got chromic acid as well which is a mixture of sulphuric and 
sodium dichromate...cleans anything..great for carbs but don't know how it 
will perform on rust..easy to check however).
Anyways any advice here would be appreciated.
later
jw