Copper Oxidation

[Tanya Harris]

Hi there,
I've just joined the forum and wondered if someone out there can help. I've just started making jewellery and have been making some earrings using copper sheet and silver wire. As much as I love the patination on copper I do love that shiny colour. I have tried coating the copper with a spray on clear lacquer and it tarnished. I think due to it not being cleaned properly. So I pickled and cleaned them properly this time and did not touch them with my hands. I coated them with 3 coats of polyurathane varnish and within 2 days they started to turn dark again. Is there ANY product out there I can use? Any advice would be appreciated.
Tanya

[CJ57]

Hi Tanya, welcome
There have been a lot of posts over the weeks/ years on this subject it might be worth doing a search and looking through the old posts.
Copper will always oxidise and spraying is the only option to seal it from the air so not sure why it’s not working for you.

[Dennis]

Hi Tanya and welcome the the forum. Form my experience with copper from different sources, some tarnishes much more quickly than others. Rightly or wrongly, I put it down to the purity and have had less trouble with copper from Cookson, than with cheaper suppliers.

Provided it is thoroughly degreased with a hot solution of soda crystals, rinsed and dried, three coats of polyurethane lacquer is as good as anything gets.
I have also tried Everbrite, which is very expensive and no better, and cellulose as used for touching up cars, which is a good alternative.

You will see that my copper box began to discolour even in the time it took to get a photograph. two years on, it is a terracotta colour. The Everbrite I tried on it did not protect it. The copper came from a cheaper company on line.Dennis.

[Sheen]

I also find soft copper tarnishes far quicker than hardened/ half hard copper. A varnish you could try is this https://www.amazon.co.uk/dp/B00UW4WT8A/?coliid=I37YXVPHTH7H5V&colid=26XFRQMQG7E9V&psc=0&ref_=lv_ov_lig_dp_it whether it would stop the tarnishing i have no idea. You can also buy them separately

[Dennis]

I think it is also worth mentioning that if you patinate shiny copper by playing a mini torch over it, you will get all sorts of bright but unpredictable colours, which are long lasting and don't need any varnishing at all.

In fact as it is a weird optical effect, it vanishes if waxed or lacquered, but can last a year or two. If there are no stones involved it can then be pickled and renewed.

My leaf below was reticulated, brushed up with a soapy brass brush and then randomly torched. Dennis.

[Tanya Harris]

Thank you for the replies. I will continue my search through the forum and trial and error I guess!