Unusual Etch on a Moro Blade

[spiral]

Originally Posted by DaveS

Spiral: I've had this happen before also after using vinegar to neutralize the
Phosphoric acid that i usually use to etch blades. It seems strange
to me that one acid can be used to neutralize another, but i guess
for some reason it works. Try also heating blades on both sides with
a torch (very carefully). Then apply acid. It seems to emphasize
the high-carbon areas of a blade with some really good results. If
the blade turns out too dark simply repolish, and try again....Dave

I think vinigar may dilute a stronger concentration of another acid Stan, but to neutralise it, will need an alkali, I think? vinigar still needs washing of or neutralising or will promote further oxidisation.

Lots of water washing & oill often suffices though.

Spiral