Black stain spreading on keris during vinegar cleaning

[Jean]

I have no real clues but just submit my personal comments and opinion:
. The blade cleaning is not complete (remaining rust spots) probably because the vinegar is too diluted. I am using undiluted vinegar at 8-10% and I cover the vertical container for avoiding evaporation of the volatile acetic acid. The cleaning procedure usually lasts 24 h only with 2 intermediate brushings.
. From the pics, the black spots look like exposed and corroded steel or iron. As said by Alan in the last thread, the blade has pamor sanak.
. Is the bad smell like rotten eggs? In this case it would be hydrogen sulphide caused by the presence of iron sulphide in the metal and attacked by the weak acid.
Regards

[Marcokeris]

Apolaki to clean the blade you can also use acid citric . You can put the blade inside 1 lt water with three little spoons of acid citric (white dust). Little by little the rust goes away. I used this way in the past with good exit.

[A. G. Maisey]

Apolaki, I believe that the black you can see is the steel core that has been hardened. The small specks in the body of the blade could be where the outside layers have worn, or, as Jean has suggested, maybe some steel is in the mix of the outside layers, but the big black areas at the point & edges are steel core.

As to cleaning with vinegar I am not nearly as scientific as either Jean or Marco. I buy ordinary white household vinegar, I have not the slightest idea of its acidity, I never dilute it. I simply wash the blade with detergent to get rid of any grease, and soak it in the vinegar. I inspect it once or twice a day and brush it as well as pick off the rust with a sharp tool, then I put it back into the vinegar. It might take me a week or more before I'm satisfied that it is clean.

Jean has my utmost admiration if he can get a truly dirty blade clean in 24 hours with only 2 brushings. Incredible! You're a better man I am Jean.

[Marcokeris]

Originally Posted by A. G. Maisey

Apolaki, I believe that the black you can see is the steel core that has been hardened. The small specks in the body of the blade could be where the outside layers have worn, or, as Jean has suggested, maybe some steel is in the mix of the outside layers, but the big black areas at the point & edges are steel core.

As to cleaning with vinegar I am not nearly as scientific as either Jean or Marco. I buy ordinary white household vinegar, I have not the slightest idea of its acidity, I never dilute it. I simply wash the blade with detergent to get rid of any grease, and soak it in the vinegar. I inspect it once or twice a day and brush it as well as pick off the rust with a sharp tool, then I put it back into the vinegar. It might take me a week or more before I'm satisfied that it is clean.

Jean has my utmost admiration if he can get a truly dirty blade clean in 24 hours with only 2 brushings. Incredible! You're a better man I am Jean.

my way to clean blades (with rust difficult to remove with other easier systems) is only empirical and rather fast.... sorry for my bad english

[A. G. Maisey]

Nitric acid is faster Marco.

But jokes aside, citric acid works well, I've used that too, and a lot of people in Indonesia currently use citric. In fact anything acidic will clean a blade, its just that I prefer vinegar because it is cheap, easy, consistent.

But if I could still get decent pineapple juice, I'd still be using that.

[apolaki]

Originally Posted by Marcokeris

Apolaki to clean the blade you can also use acid citric . You can put the blade inside 1 lt water with three little spoons of acid citric (white dust). Little by little the rust goes away. I used this way in the past with good exit.

Hi Marco,

I don't access to acid citric. Where can you get that?

Also, can I use concentrated lemon juice and water? If so, what is the recommended ratio?

[Marcokeris]

Originally Posted by apolaki

Hi Marco,

I don't access to acid citric. Where can you get that?

Also, can I use concentrated lemon juice and water? If so, what is the recommended ratio?

Hi Apolaki
I have always easily found citric acid in the pharmacy (here in Italy). Citric acid resembles as white sugar and I used this acid only with blades where the rust was very difficult to take away as old rust inside the deep of the blade's structures. When you will have the citric acid you must put some spoons of this dust into water and you must put all the blade inside this water for one day or more or less (it depends how many acid you put in the water) and , for exemple, every hour, you have to see the the blades to control the process.
Western lemon juice, in my experience, works well together bicarbonate-soda if I want to take away old warangan from the blade ...and to clean the blade before to put a new warangan

[Interested Party]

Originally Posted by Marcokeris

Hi Apolaki
Western lemon juice, in my experience, works well together bicarbonate-soda if I want to take away old warangan from the blade ...and to clean the blade before to put a new warangan

Marco what ratio of lemon juice to bicarbonate soda are you using? Are you making a paste and scrubbing with a tooth brush?

[Marcokeris]

Originally Posted by Interested Party

Marco what ratio of lemon juice to bicarbonate soda are you using? Are you making a paste and scrubbing with a tooth brush?

yes... I used exactly this way

[apolaki]

Originally Posted by Marcokeris

yes... I used exactly this way

Great! What is the ratio you use?