On 8 Jan 2006 13:43:45 -0800, wrote:

A good rust removing acid is Phosphoric Acid.

Phosphoric acid won't remove any rust at all. It will convert some of it
to phosphates (or tannates, depending on formulation). It's OK if you
just want a stable black surface to paint over, but sometimes you want
it removed.

A good solution is 50% Phosphoric Acid, 50% Acetone and a few drops of
Fairy Liquid to act as a surfactant.

Why mix it with acetone? What's the purpose?