Black stain spreading on keris during vinegar cleaning

[jagabuwana]

Mickey, when they finally make Keris Warung Kopi: The Movie, surely you will narrate.

[Interested Party]

I ran across these directions today. Gardner says: "The keris blade is next laid in a trough containing boiling rice water, sulphur, and salt, for three or four days. This blackens the steel but scarcely touches the iron. It attacks the marks of the welds, which show as tiny etched lines. When this damascened pattern is clear, the blade is cleaned with lime juice."

Two things in that caught my attention. First was the adjective boiling rice water, not boiled or simply rice water. It made me think about Mickey's trick of boiling steel in hydrogen peroxide earlier in the thread. The second was that it blackens the steel and attacks the welds, the hardest parts of the blade. esp if the flux was something such as rice straw ash that would add carbon content to the weld line. BTW what is used for flux in Keris manufacture? Either Gardner's understanding of the parts was reversed or this treatment attacks areas of higher carbon content. That to me in one way or another is interesting. If he did misunderstand the pattern does that make his use of boiling invalid?

Jugabuwana, did your blade ever get its second rice water bath or did the COVID pass through and life go back to its hectic normal? I'd love to see more pictures someday!

[A. G. Maisey]

Welding in Jawa is traditionally done in teak charcoal, the material is not welded with a flux, no flux is necessary.

I do not know the process used in old Malaya.

[Interested Party]

Interesting, today I stumbled onto the tidbit that brown rice contains more arsenic than white rice. I wonder if that means arsenic would be most concentrated in the bran? In addition rices from California, India, and Thailand are lower in arsenic than most. Second postulation; if as mentioned above, the concentration of arsenic in rice is negligible maybe rice water is used for the starch content to help evenly coat the blade for the week the reaction time the rice water/sulphur/salt slurry takes to properly stain a blade.

Sort of a related question. Does anyone know how much ground realgar one would need to stain an average keris blade?

[A. G. Maisey]

Not all realgar is equal, so the quantity required depends on the realgar, as does the result.