[Chris Goerner]

There have been a few posts in the past on antiquing brass and steel, but does anyone know how I can antique copper? I have added a plug bayonet to my reenacting gear that has a copper ferrule that is very shiny. I would like to darken it up some to make the piece look more aged. Any suggestions?

Thanks,
Chris

[D. Austin]

There are a number of different techniques, depending on the colour you are after. For a basic "aged" look, potassium sulphide comes to mind. The surface must be free from grease and oxide so sand it lightly with a fine grade emery paper (1200 grit should do) and clean thoroughly with degreaser, ensuring not to touch it after cleaning it as the oils from your skin will prevent even colouring. If left in the solution for too long, you will find that the colour will be too dark. I would recommend experimenting with some scrap copper to find a finish you are happy with.

Another technique I am a fan of (although it takes a lot longer) is to actually age it naturally. I clean the surface with emery paper, leaving it slightly rough (not polished), then leave it on a shelf in the shed for a few months. This produces a really good look.

Another option is to clean it as previously mentioned, then lightly and evenly play an oxidising flame over it. This will gradually darken the copper but again, you must stop when you're happy with the colour. Dark purple is probably not the look you're after. If with either method, you go too far and the copper becomes too dark, simply refreshen the surface with some more emery paper.

Once you are done, rinse with water and coat the piece with beeswax and polish it to preserve the finish. Alternatively, you could simply leave it uncoated to age further with time.

I just had a thought, if the ferrule can't be removed from the piece for treatment, the potassium sulphide solution might not be a great idea.

I hope this helps.

Darren.

[Chris Goerner]

Darren,

Thanks for the reply. The ferrule cannot be removed as the blade is peened to the wooden grip, so I think the potassium sulphide is out. I wasn't sure what you meant by an "oxidizing flame". Would that heat the copper so much as to cause issues with the wood it is in contact with?

Chris

[D. Austin]

Sorry Chris, the flame would burn the wood.

I guess the best option is to simply scuff the surface with emery paper. This will remove any coating that may be preventing the copper from ageing and will also increase the surface area, encouraging a natural patina to develop.

Darren.

[Tim Lison]

Put it in a ziploc (or garbage) bag with a cup of ammonia in it. The fumes from the ammonia will darken the copper very nicely and shouldn't do much to the wood.

[Peter Bosman]

I have a lot of copper thingamies on horse tack and new things look shine out of place. I cover them with horse sweat after a ride and leave it at that. It will darken very quickly to match with the rest.
It works with human sweat too as both my torques age nicely but this is marketly less argressive. Horses loose more electrolytes (salts).

peter