Minangkabau(?) keris

[Jean]

Originally Posted by A. G. Maisey

Jean, I've tried stronger vinegar, here they label it as cleaning vinegar.

What I have found is that when the material of the blade is good, dense material, well compacted and with a relatively smooth surface, the stronger vinegar does give a faster result, however, when the material is of lesser quality and not smooth and compacted the stronger vinegar tends to leave the blade looking like a sponge.

This is an example of "spongy" blade after acid cleaning as described by Alan. I used a regular household vinegar/ 10% citric acid mix for cleaning this blade but it was severely corroded, and this is the result! I should better have removed most of the rust mechanically and just polished & oiled it.
Regards