Black stain spreading on keris during vinegar cleaning

Interested Party · 17th March 2020, 04:42 PM

Quote:

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 · 17th March 2020, 05:44 PM

Quote:

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 · 18th March 2020, 12:38 AM

Quote:

Originally Posted by Marcokeris

yes... I used exactly this way

Great! What is the ratio you use?

jagabuwana · 18th March 2020, 01:01 AM

A word to the wise:

A great regret of mine is opting to use citric acid as opposed to regular white cooking vinegar, on one of my old blades.

It was the first time for me cleaning any blade.

Firstly I put too much citric acid in and it flaked some of the steel off the blade.
It was already in quite a fragile state due to its purported age, and the concentration of citric acid was far too harsh.

For this reason I will always opt to use cooking vinegar and father time.

A. G. Maisey · 18th March 2020, 01:56 AM

Jaga, I understand where you're coming from with this, and I'm of the same opinion, but only because I've used vinegar for years & years now and never had even the hint of any sort of negative result.

However, if I was new to the game I'd be looking at everything, including Coca-Cola and tomato juice. It is the nature of human kind that most people like to learn by their own mistakes.

That said, Marco used a very short term hands-on method with his citric acid. People in Solo have been using citric for years, and citric acid is what a lot of people in Solo use. Bi-carb used as a cleaner is great stuff to remove stains from tea cups and coffee cups. Bi-carb is really wonderful stuff for lots of things.

Lemon juice is in fact pretty high in citric acid to begin with. Used as a paste of bi-carb with a toothbrush I reckon it would be pretty effective. But even so, I'll stay with vinegar because of my experience with its impeccable record and because it is so easy and non-time consuming to use.

Actually, the acid in vinegar is acetic acid, and that is pretty strong stuff, but there is usually only about 5% or 6% in household white vinegar, the rest is water.

Personally, I would encourage all beginners to try everything that they can think of and to learn by their own mistakes:- there is nothing as sobering as destroying something that cost you money, by failing to learn from the mistakes of others.

apolaki · 18th March 2020, 02:29 AM

The black stain has spread throughout the blade, it is like infected the blade.

A. G. Maisey · 18th March 2020, 03:10 AM

Nothing is infected Apo, I'm looking at normal here.

Pick off the hard rust with a small, sharp tool.

Get some coarse steel wool and some powder sink cleaner, give it a good scrub under running water.

Dry it and put it back in the vinegar.

No fluid is magic, it is just a substance that helps you to get the job done. If I look at the pics of this blade I can still see a lot of what appears to be rust. I suggest you pick this off, scrub it off, as I have advised above.

When the thing is clean, dry it thoroughly and then either stain it or spray with WD40.

Jean · 18th March 2020, 11:56 AM

Quote:

Originally Posted by apolaki

The black stain has spread throughout the blade, it is like infected the blade.

Ouch, I can clearly see the coronavirus effect indeed, beware!

Jean · 18th March 2020, 12:12 PM

Quote:

Originally Posted by jagabuwana

A word to the wise:

A great regret of mine is opting to use citric acid as opposed to regular white cooking vinegar, on one of my old blades.

It was the first time for me cleaning any blade.

Firstly I put too much citric acid in and it flaked some of the steel off the blade.
It was already in quite a fragile state due to its purported age, and the concentration of citric acid was far too harsh.

For this reason I will always opt to use cooking vinegar and father time.

My personal experience is quite different from yours Jaga, probably because your blade was in too poor condition for being treated.
I tested citric acid at 10% concentration (100 g of pure citric acid powder diluted in one liter of water) in controlled conditions (regular checking) and it worked quite well without attacking the metal itself, but not better than pure vinegar. I also tested oxalic acid (used for de-rusting bolts) in similar conditions and it also worked correctly. Vinegar (acetic aid), citric acid, and oxalic acid are weak organic acids with a PH of about 3 in solution so they can safely be used with ferric metals.
By the way and as a ex-chemical engineer, I would not use citric acid and sodium bicarbonate together as the bicarbonate neutralizes the acidity of the citric acid!

A. G. Maisey · 18th March 2020, 01:14 PM

Yes Jean, I would have thought that bicarb and lemon juice together would have reduced the acidity, but Marco used it, and apparently it worked. Maybe it was just the bicarb and brushing that produced the result, bicarb just by itself is a powerful cleaner.

What effect do you think sulphur and salt together might have on ferric material?

Jean · 18th March 2020, 02:59 PM

Quote:

Originally Posted by A. G. Maisey

What effect do you think sulphur and salt together might have on ferric material?

I know that it is used Alan but I don't understand how it works as both products are basically stable and inert

However I would propose the following chemical raction chain (just my assumption, no guarantee whatsoever): the salt (NaCl) may slightly react with the metal and produce ferric or ferrous chloride (Fe Cl3 or FeCl2, highly reactive and slightly acidic) and the sulphur may react with it and produce black iron sulphide (FeS) giving the "warangan" effect on the blade.
Regards

18th March 2020, 01:01 AM	#4
jagabuwana Member Join Date: Jan 2018 Location: Sydney, Australia Posts: 290	A word to the wise: A great regret of mine is opting to use citric acid as opposed to regular white cooking vinegar, on one of my old blades. It was the first time for me cleaning any blade. Firstly I put too much citric acid in and it flaked some of the steel off the blade. It was already in quite a fragile state due to its purported age, and the concentration of citric acid was far too harsh. For this reason I will always opt to use cooking vinegar and father time. Last edited by jagabuwana; 18th March 2020 at 02:00 AM.

18th March 2020, 02:29 AM	#6
apolaki Member Join Date: Oct 2008 Posts: 160	The black stain has spread throughout the blade, it is like infected the blade. Attached Images

18th March 2020, 01:56 AM	#5
A. G. Maisey Member Join Date: May 2006 Posts: 6,992	Jaga, I understand where you're coming from with this, and I'm of the same opinion, but only because I've used vinegar for years & years now and never had even the hint of any sort of negative result. However, if I was new to the game I'd be looking at everything, including Coca-Cola and tomato juice. It is the nature of human kind that most people like to learn by their own mistakes. That said, Marco used a very short term hands-on method with his citric acid. People in Solo have been using citric for years, and citric acid is what a lot of people in Solo use. Bi-carb used as a cleaner is great stuff to remove stains from tea cups and coffee cups. Bi-carb is really wonderful stuff for lots of things. Lemon juice is in fact pretty high in citric acid to begin with. Used as a paste of bi-carb with a toothbrush I reckon it would be pretty effective. But even so, I'll stay with vinegar because of my experience with its impeccable record and because it is so easy and non-time consuming to use. Actually, the acid in vinegar is acetic acid, and that is pretty strong stuff, but there is usually only about 5% or 6% in household white vinegar, the rest is water. Personally, I would encourage all beginners to try everything that they can think of and to learn by their own mistakes:- there is nothing as sobering as destroying something that cost you money, by failing to learn from the mistakes of others.

18th March 2020, 03:10 AM	#7
A. G. Maisey Member Join Date: May 2006 Posts: 6,992	Nothing is infected Apo, I'm looking at normal here. Pick off the hard rust with a small, sharp tool. Get some coarse steel wool and some powder sink cleaner, give it a good scrub under running water. Dry it and put it back in the vinegar. No fluid is magic, it is just a substance that helps you to get the job done. If I look at the pics of this blade I can still see a lot of what appears to be rust. I suggest you pick this off, scrub it off, as I have advised above. When the thing is clean, dry it thoroughly and then either stain it or spray with WD40.

18th March 2020, 01:14 PM	#10
A. G. Maisey Member Join Date: May 2006 Posts: 6,992	Yes Jean, I would have thought that bicarb and lemon juice together would have reduced the acidity, but Marco used it, and apparently it worked. Maybe it was just the bicarb and brushing that produced the result, bicarb just by itself is a powerful cleaner. What effect do you think sulphur and salt together might have on ferric material?