Oxalic acid is used to clean rust from fabric and rocks, so it should work
on porcelain.

>Our museum has several license platees that have porcelain fronts.  On the
front of the porcelain, however, are rust stains from other objects and
being improperly stored.  We would like to remove the stains if possible.
So I have a few questions:
>
>Has anyone cleaned rust from porcelain, without damaging the porcelain?
How would we remove the stains and what kind of materials would we need to
remove the stains if we can?