Black rust

[kulbuntet]

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]

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]

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]

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

[Sajen]

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]

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

Regards,

Heinz

[kai]

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