Black rust

Sajen · 19th April 2010, 07:15 PM

Quote:

Originally Posted by Greybeard

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

Hello Heinz,

when you clean a blade in the way I have described and control it by time and don't let it to long inside only the corrosion going. I have cleaned many different blades like this and every time have had good results.

Regards,

Detlef

Greybeard · 20th April 2010, 05:37 AM

Thank you, Detlef. I think I'll try it coming weekend.

Regards,

Heinz

kai · 21st April 2010, 11:00 PM

Hello Heinz,

Truth is, there will always be a bit of corrosion when placing iron/steel into acids - not that much of an issue with keris though if you're working with well diluted acids. Still, it's advisable to keep the exposure as short as possible by regularly checking the progress and frequently brushing the blade. The degreasing step should be done very carefully so that the acid can work evenly across the whole blade; also scraping thick deposits of rust/gunk off the blade with something safe like a piece of hardwood will help.

Pinapple juice works nicely and is supposed to be the gentlest of the fruit acids. If you have to work indoors with prolonged soaking times, the odors of the aged fluid may be a bit of a challenge though.

The advantage of acetic acid (vinegar) is that it is also acting as a vapor which seems to help reaching into crevices and loosening up tougher deposits. The active ingredient of several traditional cleaning solutions (like coconut "water") is acetic acid, too. Household acetic acid usually has about 10% strength while kitchen vinegar is around 4%. Check with the label and dilute to 0.5-1% for a start and go from there.

Regards,
Kai

Greybeard · 22nd April 2010, 05:45 AM

Hello Kai,

Many thanks for the valuable information.

Regards,

Heinz

Greybeard · 3rd May 2010, 05:53 AM

This weekend I cleaned a spotted keris blade by using diluted vinegar. It worked great -- all the black rust spots are gone! Thank you all for your advice.

Regards,

Heinz

20th April 2010, 05:37 AM	#2
Greybeard Member Join Date: May 2009 Location: Switzerland Posts: 124	Thank you, Detlef. I think I'll try it coming weekend. Regards, Heinz

21st April 2010, 11:00 PM	#3
kai Member Join Date: Apr 2005 Posts: 3,255	Hello Heinz, Truth is, there will always be a bit of corrosion when placing iron/steel into acids - not that much of an issue with keris though if you're working with well diluted acids. Still, it's advisable to keep the exposure as short as possible by regularly checking the progress and frequently brushing the blade. The degreasing step should be done very carefully so that the acid can work evenly across the whole blade; also scraping thick deposits of rust/gunk off the blade with something safe like a piece of hardwood will help. Pinapple juice works nicely and is supposed to be the gentlest of the fruit acids. If you have to work indoors with prolonged soaking times, the odors of the aged fluid may be a bit of a challenge though. The advantage of acetic acid (vinegar) is that it is also acting as a vapor which seems to help reaching into crevices and loosening up tougher deposits. The active ingredient of several traditional cleaning solutions (like coconut "water") is acetic acid, too. Household acetic acid usually has about 10% strength while kitchen vinegar is around 4%. Check with the label and dilute to 0.5-1% for a start and go from there. Regards, Kai

22nd April 2010, 05:45 AM	#4
Greybeard Member Join Date: May 2009 Location: Switzerland Posts: 124	Hello Kai, Many thanks for the valuable information. Regards, Heinz

3rd May 2010, 05:53 AM	#5
Greybeard Member Join Date: May 2009 Location: Switzerland Posts: 124	This weekend I cleaned a spotted keris blade by using diluted vinegar. It worked great -- all the black rust spots are gone! Thank you all for your advice. Regards, Heinz