Black rust

Greybeard · 15th April 2010, 08:28 AM

Sirek, Kronckew, thank you both for your suggestions.

p.s. - black iron oxide is an alternative form of rust to the more destructive red rust we all hate. rust bluing is/has been used to produce a nice blue/black protective coating on steel, and the black ferrous oxide coating is somewhat protective against red rust, and is the major component in the patina steel aquires over the years. removal of black rust or patina from antiques may lower their value.[/QUOTE]

I think it will be best to leave the "black rust" alone and just plane off the high spots with a brass scraper. My home-made brass tools have always been very useful for a gentle (red/brown) rust removal without harming the patina.

Heinz

kulbuntet · 16th April 2010, 11:57 PM

dilute vinegar

Greybeard · 19th April 2010, 08:28 AM

Quote:

Originally Posted by kulbuntet

dilute vinegar

Thank you, Kulbuntet. Would grapefruit juice or pineapple juice also help? Seems less aggressive to me than vinegar.

Regards,

Heinz

kulbuntet · 19th April 2010, 12:04 PM

Hello Heinz,

You can always try. I prefer Diluted Vinigar for think black rust. And brush it away with a brass bursh. It works fine for me. The vinigar is not a strong acid, and les strong iff you dilute it a bit. It wil destroy the stucture of the rust, what you can bush of the next day.

Regards Abdulrahman (formerly Michel)

PS you can also have a look at this product. I realy works!!
Bio deruster link

Greybeard · 19th April 2010, 01:20 PM

Quote:

Originally Posted by kulbuntet

Hello Heinz,
PS you can also have a look at this product. I realy works!!
Bio deruster link

Hello Abdulrahman,

Very interesting product! I think I'll try diluted vinegar first.

Thanks and regards,

Heinz

Sajen · 19th April 2010, 02:47 PM

Hello Heinz,

what works fine and certain is lemon acid you can buy in the supermarket. I use a drain pipe closed at one side and hang the blade inside, when you contol it time by time the acid only destroy the corrosion. This blade for example is cleaned by lemon acid.

Regards,

Detlef

Greybeard · 19th April 2010, 06:38 PM

Hello Detlef,

Very nice result! I see that there are several options. I'll just have to try ...

I have always been very hesitant in using acidic solutions for cleaning purpose on metal surfaces. Being a long-time firearms collector, I believed in the formula
iron/steel + acid = corrosion.

The keris that I intend to clean is -- except for several black rust spots -- a very nice dapur Parungsari in a grey/white condition with smooth edges and beautifully executed luk rengkol. All I want is to preserve it in this shape.

Regards,

Heinz

19th April 2010, 02:47 PM	#6
Sajen Member Join Date: Aug 2007 Location: Germany, Dortmund Posts: 9,272	Hello Heinz, what works fine and certain is lemon acid you can buy in the supermarket. I use a drain pipe closed at one side and hang the blade inside, when you contol it time by time the acid only destroy the corrosion. This blade for example is cleaned by lemon acid. Regards, Detlef Attached Images

15th April 2010, 08:28 AM	#1
Greybeard Member Join Date: May 2009 Location: Switzerland Posts: 124	Sirek, Kronckew, thank you both for your suggestions. p.s. - black iron oxide is an alternative form of rust to the more destructive red rust we all hate. rust bluing is/has been used to produce a nice blue/black protective coating on steel, and the black ferrous oxide coating is somewhat protective against red rust, and is the major component in the patina steel aquires over the years. removal of black rust or patina from antiques may lower their value.[/QUOTE] I think it will be best to leave the "black rust" alone and just plane off the high spots with a brass scraper. My home-made brass tools have always been very useful for a gentle (red/brown) rust removal without harming the patina. Heinz

16th April 2010, 11:57 PM	#2
kulbuntet Member Join Date: Oct 2008 Location: Amsterdam, Netherlands Posts: 159	dilute vinegar

19th April 2010, 12:04 PM	#4
kulbuntet Member Join Date: Oct 2008 Location: Amsterdam, Netherlands Posts: 159	Hello Heinz, You can always try. I prefer Diluted Vinigar for think black rust. And brush it away with a brass bursh. It works fine for me. The vinigar is not a strong acid, and les strong iff you dilute it a bit. It wil destroy the stucture of the rust, what you can bush of the next day. Regards Abdulrahman (formerly Michel) PS you can also have a look at this product. I realy works!! Bio deruster link

19th April 2010, 06:38 PM	#7
Greybeard Member Join Date: May 2009 Location: Switzerland Posts: 124	Hello Detlef, Very nice result! I see that there are several options. I'll just have to try ... I have always been very hesitant in using acidic solutions for cleaning purpose on metal surfaces. Being a long-time firearms collector, I believed in the formula iron/steel + acid = corrosion. The keris that I intend to clean is -- except for several black rust spots -- a very nice dapur Parungsari in a grey/white condition with smooth edges and beautifully executed luk rengkol. All I want is to preserve it in this shape. Regards, Heinz