Protective Finish for Copper

by Riki
(Israel)

How can one prevent copper from turning green and is there a coating that would protect the client's skin?
Thank you,
Riki

Stacy's Answer:

Thanks for your question, Riki. Copper will eventually turn green when exposed to air and moisture unless you protect it. There are a variety of materials used to protect copper...from waxes, which are temporary, to lacquers, which are more permanent. I generally prefer the lacquers.

Rio Grande makes a nice sealant called Midas® Finish Seal Lacquer, which is easy to apply and water soluble until it dries. However, I've found that the metal does continue to oxidize, albeit at a much slower rate, under the coating. It also wears off in areas that get a lot of friction.

My current sealant of choice is Permalac® EF because the fumes are not so noxious, it forms a nice hard shell and it does a better job of protecting the metal from further oxidation. The downside is that it's more difficult to use than Midas® and other sealers, though I've found it's worth the extra effort.

Comments for Protective Finish for Copper

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Jun 26, 2016
Permalac NEW
by: Irene

Stacy,
First, thanks for being a fantastic resource person!
Permalac users have reported some problems with receiving solutions with precipitates that dry with a purple hue. Have you experienced any recent issues with this product?

Jun 26, 2016
Permalac NEW
by: Irene

Stacy,
First, thanks for being a fantastic resource person!
Permalac users have reported some problems with receiving solutions with precipitates that dry with a purple hue. Have you experienced any recent issues with this product?

Aug 28, 2015
Lacquer Coating for Copper
by: Stacy

Thanks for sharing! I like the Sculpt Nouveau EF and also Permalac EF lacquers. But I haven't tried the regular Sculpt Nouveau clear sealant. I've got a new can of the Sculpt Nouveau, I'll give it a try!

Aug 28, 2015
Total Success With This Copper Coating
by: Anonymous

This was an on-going problem until a fellow jeweler sent me a message on FB...take a section of wire and dip it in liver of sulfur and after a few seconds in a water solution with baking soda in t. Let dry. Seal the piece with Sculpt
Nouveau---a clear sealant made especially for copper and a fabulous coating. So far has been totally full proof for preventing 'greening' even in the most sensitive person. I love working in copper now and never worry. Be sure not to leave in the liver of sulfur solution too long (too dark). If I am doing a strictly wire piece for jewelry I go ahead and form it first and then go through the process. This is actually a very easy process after a couple of times. I use Sculpt Nouveau REGULAR and not ENVIRONMENTAL.

Jul 06, 2013
Penny Project
by: Anonymous

Hi!
I just finished a paper mache letter covered with pennies. I want to put a shiny protective coat over it that will help keep the pennies copper color and also fill in the groves. I was going to use decoupage, but I'm afraid it will turn out cloudy. Any suggestions? :)
Thanks!

May 03, 2012
Copper bangle
by: Anonymous

I have a copper bangle that turned a very dull colour. Someone recommended I polish it with Brasso. Sadly this has taken all the lacquer finish off it. Now it is worse than before. Please could you give me some advice on how to polish it and possibly recommend a lacquer so that I can return it to its original beautiful shine.
Thank you.

Jan 15, 2010
Is there a way to tumble the coating on?
by: Colleen

I've read about products like lacquer and Renaissance Wax, but in all of them the requirement is to rub, dip, otherwise apply some kind of semi-liquid substance to the piece. I'm very concerned about drips, and have a small workspace with not many spaces to hang things to safely dry.
Are there any products which allow you to TUMBLE them onto the copper? This seems ideal for intricate pieces, but I don't know what to use. Is there a good tumble-on product that will prevent copper tarnish? Bonus if it won't damage my rotary barrels :)

Nov 17, 2009
Thank you
by: Riki

Dear Stacy,
Thank you again. Do you have an artice on patinas?
Riki

Stacy's Answer:

You are welcome Riki! As a matter of fact, there is a very detailed article here that I've written about the liver-of-sulfur patina. I also teach a workshop on different patinas and will be adding additional articles on various patina finishes soon.

Nov 16, 2009
Thank you, Stacy
by: Riki

Dear Stacy,
Thank you! Now I can make copper jewelry and know it will look good for a long time! Does the lacquer have to be applied with a brush?
Riki

Stacy's Answer:

Riki, I've found that it's really a personal preference as to whether you apply the lacquer with a brush or you dip the piece into the lacquer. Brushing it on is a more accurate way of applying it, like when you need to avoid lampwork beads or gemstones, or to apply the lacquer in a specific area. However, if you have a complex jewelry piece with lots of cracks and crevices, you may get better results if you dip it. I do re-use my lacquer; however, I have separate containers of lacquer for clean or liver-of-sulfur patinas, blue and green patinas. This helps avoid accidentally adding a patina that you may not want to your copper.

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