Back to Ganoksin | FAQ | Contact

Lacquering copper


#1

I’m new here and new to metalsmithing. I’m taking classes at my
local Arts Center. I like to work with copper, but worry about it
staining the skin. My niece wants me to send her some of my pieces,
and I’ll be embarrassed if she ends up with green skin. I tried using
wax (I believe it was Carnauba). I wore a collar to test it on the
4th and in about 3 hours the entire piece had darkened (it was hot
though). So, I’m thinking that’s not the way to go. I’m curious about
lacquer. How does it wear? Does it devalue the piece (as if mine had
value)? Can you shine with a polishing cloth with lacquer on? Would
like to hear some opinions or options. I’d rather keep the pieces in
their natural state and advise her to keep them polished, but I don’t
want her to end up with green skin either.

Thanks so much.
Ramona


#2

Hello Ramona,

Many people wear copper and believe it relieves arthritis - no
comment on this from me. They let the copper patina as it will and
live with the dark marks on their skin. The marks do wash off.

Copper can be polished and lacquered, but the lacquer will indeed
wear off and if the copper is bent at all, the lacquer will chip off.
Because copper is “bendy”, lacquer is not a good option for most
pieces. If you have torched copper, you may have noticed that it
will take on a wonderful reddish finish. That finish can be lightly
buffed and is quite durable; however, it is not permanent and like
any coating, it will wear through.

I have had the best success with keeping the polished finish on
copper when it is soldered to another metal like silver or brass,
then buffed and given a coat of lacquer or wax. The backing metal
takes the abuse and protects the copper’s surface… for a while.

In your shoes, I’d experiment with patinas (either from chemicals or
heat). Make the patina part of the design and desirable - sort of
making lemonade out of lemons. It will be interesting to see what
solutions are provided by our wonderful Orchid community,

Judy in Kansas


#3

Hi Judy,

I have had the best success with keeping the polished finish on
copper when it is soldered to another metal like silver or brass,
then buffed and given a coat of lacquer or wax. The backing metal
takes the abuse and protects the copper's surface... for a while. 

To solder the copper to silver and have better protection against
oxidation sounds to me like the phenomenon of sacrificial metal,
whereby one metal is in contact with a more reactive metal to prevent
or slow down the corrosion of the less reactive metal. The more
reactive metal is “sacrificed” to protect the less reactive metal. An
example is steel ship hulls having blocks of zinc attached to slow
down the corrosion of the steel from the salt water.

However, copper is more reactive than silver so it seems that the
copper would oxidise more readily if attached to silver. Or have I
completely got the wrong end of the stick and you are putting a
backing of silver or brass onto the copper so that the copper is not
in contact with the skin, therefore preventing any electrochemistry
with the skin?

Helen Hill
Preston, UK


#4

Hello Helen,

Soldering copper to silver serves two purposes.

One (as you suggested) is to reduce the contact with the wearer’s
skin. Less likely to result in that dark color where copper touches
one’s skin.

The second is to provide a sturdier back to the more flexible copper
so that it is less likely to bend and pop off any finish that was
applied. However, any finish is a temporary barrier and in time, will
wear off to expose the copper and allow it to patina.

Judy in Kansas, who FINALLY picked some ripe tomatoes! Yum!