Gold, silver and steel case.

This is a Japanese cigarette case, about 3 inches square, that started life with the gold and silver inlay showing against a near black background due to a 'blueing' treatment of the steel that leaves it covered with a very thin layer of magnetic iron oxide, closely chemically related to regular rust but without the tendency to swell up and fall off.

This is often referred to as a 'gunmetal' finish.



Trouble is wear over the years turns the even black to the patchy grey and rust you see above. The back is even worse.


The inside is the original colour.



Has anyone got any ideas for 'smartening' this up? As it stands it is of minimal value so there is nothing much to lose. Brasso? (old joke)

(The two shiny drops on the back are just water, probably my tears at its condition.)

 

Mineral oil will do a light cleaning and seal the areas that are starting to rust.
I doubt you can bring it back to "good" condition.

 

I forgot to say, I think this is damascene, also called niello when done on jewelry

 

Doesn't soaking in coca cola remove rust ? Would it hurt the gold and silver ?

 

Niello is a sulphur blackening process in silver, this is actual metal inlay, albeit very thin. I suppose I could try polishing and re-blueing the whole thing with gun blue.

 

Would re-bluing damage the inlays?

 

Metalsmith Fred Zweig has been researching Japanese damascene (nunome-zogan) for several years now - perhaps he might have some advice. Feel sure he'd like to add your images to his files - looks like your mark might be a variant on one found in the middle of the 12th row from the bottom: https://plus.google.com/photos/102435678137937795850/albums/5948493028195661489?banner=pwa

~Cheryl

 

Hi AF,
I would wash and soak the spots with vinegar. It will remove the "rust" and leave just a discolored area. Then paste wax it. It should look better. I used that on an old rifle I had that the gun metal polish wore away. It looked a lot better.
greg

 

What is paste wax?

 

Hi,
Any solid wax like clear shoe polish. I use Butcher's wax or car wax or the best is shoe wax. Rub it on and then buff it. You want the removed "rust" from coming back.
greg

 

Fair enough. It just seems a shame after what seems to be fine work that it should end up in my odds and sods bin.

 

Naval jelly has a tendency to turn treated steel black

I think its phosphoric acid

It removes bluing

 

af, you might buy a Sunshine Cloth, available from sellers on Fleabay US. I've found them pretty effective with this sort of degradation.

 

Is that different to a Goddards silver cloth?

 

Yup. I use Goddards on silver, as one might guess. The Sunshine Cloths seem to work much better on nasty gunk, and also are very effective on tarnished or mucky gold. They seem more generalist, for want of a better word - even on pearls or opals. I've bought from a seller called verasjewelry if I've got the spelling right. Decent price and reliable.

I'd also say it's damascene, not Niello, agreed. Damascene being inlay and all that. Niello is what is used often in jewellery marked Siam, as an aside.