Black stain spreading on keris during vinegar cleaning

Interested Party · 27th March 2020, 06:52 PM

Quote:

Originally Posted by Rick

Rice contains arsenic at a relatively high level compared to most other foods.

Wikipedia, the source of all reliable information, states, "As arsenic is a natural element in soil, water, and air, the United States Food and Drug Administration (FDA) monitors the levels of arsenic in foods, particularly in rice products used commonly for infant food.[20] While growing, rice plants tend to absorb arsenic more readily than other food crops, requiring expanded testing by the FDA for possible arsenic-related risks associated with rice consumption in the United States.[20] In April 2016, the FDA proposed a limit of 100 parts per billion (ppb) for inorganic arsenic in infant rice cereal and other foods to minimize exposure of infants to arsenic.[20]."

Thus its seems if the key to the rice water stain process is arsenic, where the rice is grown would greatly affect the quality of the stain. So possibly the region in which this technique originated it was highly effective due to very high concentrations of arsenic in the soil. The downside is that the local population's health may have been compromised.

Jean · 27th March 2020, 07:59 PM

Quote:

Originally Posted by Interested Party

In April 2016, the FDA proposed a limit of 100 parts per billion (ppb) for inorganic arsenic in infant rice cereal and other foods to minimize exposure of infants to arsenic.[20]."

100 ppb is equivalent to 0.1 PPM (part per million) so a very very low concentration. Even if the arsenic content in the rice water is higher than in the rice itself, I doubt it very much that it could be sufficient for creating any warangan effect.
For comparison, the arsenic concentration in realgar (arsenic sulphide ore, the most commonly used chemicals for warangan treatment) amounts to several percents so thousands time more than in the rice (one percent is equivalent to 10,000 PPM)....

kai · 27th March 2020, 10:48 PM

I agree that even possibly elevated amounts of arsenic in rice are a red herring for the salt+sulphur recipe. While the salt is acting as a corrosive agent, the stain will result from reactive sulphur compounds.

Regards,
Kai

A. G. Maisey · 28th March 2020, 01:44 AM

Cupla thangs Mickey.

Number one:- I'm Aussie. In general, Aussies from my generation and before tend not to take very much, very seriously. I take a few things relatively seriously, but mostly the tongue is edging towards the cheek.

Number two:- retirement is a ticket to hell, and I'm in no hurry to get there. You stop work, you go rotten, then you die. Nobody can afford to retire.

Number three:- the "Living Legend" with all due apologies, I've never heard such nonsense. I started younger than most people, I've continued longer than most people, my debt to the true Legends who taught me is enormous. I'm no Legend, just lucky. Right time, right place, that's all.

As for the rice water stain, warangan works better. That one I've shown a picture of is better than a couple of others I tried later. Laboratory quality arsenic trioxide works best --- problem these days is that without the required qualification and certificate, you cannot get it.

jagabuwana · 30th March 2020, 06:26 AM

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

Interested Party · 31st May 2020, 07:11 AM

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 · 31st May 2020, 11:53 AM

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.

27th March 2020, 10:48 PM	#3
kai Member Join Date: Apr 2005 Posts: 3,255	I agree that even possibly elevated amounts of arsenic in rice are a red herring for the salt+sulphur recipe. While the salt is acting as a corrosive agent, the stain will result from reactive sulphur compounds. Regards, Kai

28th March 2020, 01:44 AM	#4
A. G. Maisey Member Join Date: May 2006 Posts: 7,047	Cupla thangs Mickey. Number one:- I'm Aussie. In general, Aussies from my generation and before tend not to take very much, very seriously. I take a few things relatively seriously, but mostly the tongue is edging towards the cheek. Number two:- retirement is a ticket to hell, and I'm in no hurry to get there. You stop work, you go rotten, then you die. Nobody can afford to retire. Number three:- the "Living Legend" with all due apologies, I've never heard such nonsense. I started younger than most people, I've continued longer than most people, my debt to the true Legends who taught me is enormous. I'm no Legend, just lucky. Right time, right place, that's all. As for the rice water stain, warangan works better. That one I've shown a picture of is better than a couple of others I tried later. Laboratory quality arsenic trioxide works best --- problem these days is that without the required qualification and certificate, you cannot get it.

30th March 2020, 06:26 AM	#5
jagabuwana Member Join Date: Jan 2018 Location: Sydney, Australia Posts: 291	Mickey, when they finally make Keris Warung Kopi: The Movie, surely you will narrate.

31st May 2020, 07:11 AM	#6
Interested Party Member Join Date: Dec 2019 Location: Eastern Sierra Posts: 505	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!

31st May 2020, 11:53 AM	#7
A. G. Maisey Member Join Date: May 2006 Posts: 7,047	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.