Does anybody use rust converters ( Rust-Oleum, Corroseal et al)?
It has tannin, that converts rust to black magnetite and a polymer to seal it completely?
There is no way to de-rust examples like Bandook's katars without leaving only a foil-thin sliver of live steel.
I have shown here a 15-16th century bauernwehr preserved like that. That's how the surface looks like
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