Brown Copper

by Norma

I use Liver of Sulfur gel to oxidize copper. I clean the excess off before putting it in my tumbler. I use Dawn detergent when tumbling copper. I then put only enough water in the tumbler to cover the shot and copper. The tumbler, Lortone, runs from 30 minutes to 2-3 hours. When I take the copper out, it is shiny, but it is a brown color. It also looks like it has a think "coat of plastic" over it. After tumbling, I clean the shot in clear water and lay it on a mat to dry. How can I keep the copper from getting that brown color?

Stacy's Answer:

Hi Norma!

The tumbled copper often comes out of the tumbler an even, medium brown color. The strength and temperature of the patina, the darkness of the patina-on-metal, how much of the LOS is removed and length of tumbling time all contribute to it's finished color. I usually tumble-polish my items first to give the metal a very high polish finish before adding a patina. Here are a few techniques to give you a different result with copper and the LOS patina.

For a black color, I super heat both the LOS solution and the metal, (heat metal by submerging in very hot water, not by torching) and dip repeatedly if necessary until a black color is achieved. Let dry, then tumble an hour or so.

For a bronzed look, same process but tumble for 6-7 hours.

For more copper highlights, remove excess LOS patina from the high areas of the jewelry. This is easier to do while the patina is still wet, then tumble 2-4 hours.

To give jewelry a beautiful finish after tumbling with the patina, I buff by hand using a jewelry polishing cloth. I prefer the Sunshine clothes by Rio Grande for copper.

Use a slightly cooler solution or quick-dip cold (room temperature) metal for a very light patina. Tumble and then buff with a Sunshine cloth.

For a satin or brushed look, use a fine scrubby pad like 0000 steel wool or a 3M scrubby to remove the excess patina. The texture of the scrubby leaves a brushed finish on the metal. You may scrub the metal after tumbling with the patina, or directly after you add the patina, but do not tumble a second time. Tumbling will remove the satin/brushed texture you've added. How fine or coarse the scrubby is creates a slightly different finish. Experiment with them to find a look you like best. Protect with a matte-finish lacquer as a shiny one will ruin the satin effect.

If left to its own devices, copper will turn brown like a penny. Bright copper and most patinas-on-copper require some sort of protective coating such as a wax or lacquer finish to preserve them.

Click here to post comments

Return to Tumble Polishing Q & A.