Ethnographic Arms & Armour - View Single Post

ariel · 19th October 2021, 05:00 AM

I think I might know why coffee gives dark black wootz lines.
Coffee is acidic and oxidizes ( rusts) areas with higher content of carbon. But at the same time it contains tannins that convert rust into permanent black Fe tannate.
This is similar to the so-called "rust converters".

19th October 2021, 05:00 AM	#48
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	I think I might know why coffee gives dark black wootz lines. Coffee is acidic and oxidizes ( rusts) areas with higher content of carbon. But at the same time it contains tannins that convert rust into permanent black Fe tannate. This is similar to the so-called "rust converters".