What removes rust instead of converting it to a phosphate?

A wire brush, Sand paper, a grinding wheel, media blasting or other abrasives. Anything that "dissolves" rust will leave an iron salt residue whether it's a chloride (muriatic acid), a phosphate (phosphoric acis) or some other compound of iron. It's the nature of the chemistry.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

Thanks

Well, there's an acid that would just wash it away, but it's so hellacious even a nut like me wouldn't use it.