Does copper luster oxidize?

[Erik Brown]

I tried searching the new and old boards for "copper luster/lustre oxid*" and didn't see my specific question, so here it is:

In the Brock and Avery class we used Hanovia Gold Luster. I plan to play with gold, platinum, and copper lusters as soon as the electrical work is done on the garage. I was wondering if anybody knew whether the copper luster oxidizes with exposure. I thought I saw some copper luster used on one of Avery's example pieces. Does the copper have to be protected with some sort of coating, or does it get absorbed into (and thus is protected by) the glass like the micas?

Thanks!

Erik

[Michael]

I have pieces of copper lustred glass two years old, unlike their Raku pottery equivalent they haven't changed at all. Copper tends to give a variety of colours depending on thickness and temp from blue/greens through to pink and copper . Hope this helps
Michael

[Avery Anderson]

Does the copper have to be protected with some sort of coating, or does it get absorbed into (and thus is protected by) the glass like the micas?

Thanks!

Erik

Hi Erik:

Copper Lusters (by Hanovia) do not oxidize. They are stable once fired to maturation and will not change over time. The do not need to have any type of coating. However, in firing, they are not as forgiving with temperature as the Gold and Platinum. Run a test and fire between 1300 and 1350 and monitor the firing visually. Be sure to vent your kiln at least up to 1000.

Avery

[Erik Brown]

Michael>>> I have pieces of copper lustred glass two years old, unlike their Raku pottery equivalent they haven't changed at all. Copper tends to give a variety of colours depending on thickness and temp from blue/greens through to pink and copper . Hope this helps
<<< Michael

Thanks! Hmmm... I hope the color shifting is controllable...

Avery>>> Hi Erik:

Copper Lusters (by Hanovia) do not oxidize. They are stable once fired to maturation and will not change over time. The do not need to have any type of coating. However, in firing, they are not as forgiving with temperature as the Gold and Platinum. Run a test and fire between 1300 and 1350 and monitor the firing visually. Be sure to vent your kiln at least up to 1000.

<<< Avery

Hi Avery!

Thanks for the information. That's just what I wanted to hear! I have a couple of ideas for some Christmas tree ornaments, and I was hoping I wouldn't have to use coatings to protect the copper (somehow just doesn't seem right).

What would I be looking for when performing the firing? Am I trying to control the color variations Michael mentions, or just catch it before the copper burns off?

Thanks again!

Erik

[charlie]

Hi Avery!

Thanks for the information. That's just what I wanted to hear! I have a couple of ideas for some Christmas tree ornaments, and I was hoping I wouldn't have to use coatings to protect the copper (somehow just doesn't seem right).

if you look at the magless i did, the star is copper hanovia luster. it doesn't oxidize, but if overfired, it will look oxidized. it turns sort of brownish. it can be polished up with a light buffing.

What would I be looking for when performing the firing? Am I trying to control the color variations Michael mentions, or just catch it before the copper burns off?

Thanks again!

Erik

it won't turn colors like it does for pottery.

[Avery Anderson]

[quote="Erik Brown"Thanks for the information. That's just what I wanted to hear! I have a couple of ideas for some Christmas tree ornaments, and I was hoping I wouldn't have to use coatings to protect the copper (somehow just doesn't seem right).

What would I be looking for when performing the firing? Am I trying to control the color variations Michael mentions, or just catch it before the copper burns off?

Thanks again!

Erik[/quote]

Hi Erik:

Charlie beat me in answering, and he is absolutely correct. Do a test piece and look at it beginning at about 1250....when it becomes bright and shiny, hold it at that temp for about 5 minutes, and then ramp down. The copper burns out easily, as Charlie said, so you have to monitor your first firing to know where it will mature in your particular kiln.

Good luck,
Avery

[Erik Brown]

charlie>>> if you look at the magless i did, the star is copper hanovia luster. it doesn't oxidize, but if overfired, it will look oxidized. it turns sort of brownish. it can be polished up with a light buffing.<<<

I tried a quick search and looked at the links at the top of the page. Where can I see a picture of your magless?

And thanks for the info!

Erik

[Erik Brown]

Avery>>> Hi Erik:

Charlie beat me in answering, and he is absolutely correct. Do a test piece and look at it beginning at about 1250....when it becomes bright and shiny, hold it at that temp for about 5 minutes, and then ramp down. The copper burns out easily, as Charlie said, so you have to monitor your first firing to know where it will mature in your particular kiln.

Good luck,
Avery<<<


Okeydokey. Thanks again! 8-)

Erik

[charlie]

cI tried a quick search and looked at the links at the top of the page. Where can I see a picture of your magless?

And thanks for the info!

Erik

http://www.warmglass.org/mag2003_pictures/1.jpg

the complete list is at http://www.warmglass.org/participants.html. click on the # to see a picture of a specific one.