My copper turned black

Judy Schnabel · Post by **Judy Schnabel** » Mon Jan 19, 2004 12:05 pm

I've experimented with copper (purchased from Michael's) fired between layers of float and have had reasonably good results.

However, I thought I'd have better results if I ordered thinner copper from Nimrod Hall. I ordered the thinnest copper they had and did some test runs yesterday. Fired the copper between two layers of float with some Pearl Ex on the copper. Fired them to 1500.

I opened the kiln this morning and all the thin copper had turned black.
I also had a design with the last piece I had purchased from Michael's. It turned out beautiful.

I'm assuming the thin copper just burns up at 1500.

Maybe I should have tried firing it between layers of art glass instead.

Comments?

Judy

rosanna gusler · Post by **rosanna gusler** » Mon Jan 19, 2004 1:24 pm

borax will keep it red. spray and dry before assembling to avoid spit bubbles. ferro frits will keep the copper shiny. texas tom sais unique clear does the same. rosanna

Kathie Karancz · Post by **Kathie Karancz** » Mon Jan 19, 2004 1:35 pm

Hey Judy: I just did a firing on the weekend using Spectrum glass with copper I bought from Bullseye and it turned out good. I didn't fire any higher than around 1450 degrees so maybe you are firing too high.

jolly · Post by **jolly** » Mon Jan 19, 2004 2:51 pm

The copper is turning black because it has enough oxygen to react with. The solutions suggested all keep the oxygen from interacting with the copper. What is the thickness of the two different foils? I find that if I get the copper very close to the edge of the glass, it holds up the glass a bit, allowing air to get to the copper for a longer period of time. Copper doesn't seem to change at all until at least 900 d F. On large pieces, I put shards on the edges to allow the deep red to reach further into the center of the piece. I get my copper foil from Alaska Copper and Brass and it is 'one ounce' copper (weighs 1 oz per square foot) or .001. If you use a lot it is MUCH cheaper that way. -Jolly

Judy Schnabel · Post by **Judy Schnabel** » Mon Jan 19, 2004 5:53 pm

The first time (many months ago) I played with copper, I took Tom's suggestion and painted Unique clear on it. After it was fired, I could see the brush marks. I didn't like that.

This time I didn't put anything on either thickness.

The stuff that turned black is 1 mil (.001 inch). From the samples Nimrod Hall sent, I'd say the copper from Michael's is about 5 mil. That's the piece that stayed nice and bright.

I'll try the Borax solution next time.

Does anyone else fire with copper this thin?

When I ordered it, I asked what thickness do most fusers use and this was what they suggested.

Judy

Barbara Muth · Post by **Barbara Muth** » Mon Jan 19, 2004 6:58 pm

Judy, was your copper sandwiched or on the surface?

Judy Schnabel · Post by **Judy Schnabel** » Mon Jan 19, 2004 8:28 pm

Barbara,

It was sandwiched between two layers of double strength float.

I've done this several times with relatively good results until I switched to this thin copper.

Judy

jolly · Post by **jolly** » Tue Jan 20, 2004 12:29 am

I only use the thin (.001) copper foil. I also use float. If I get it closer than about 1/8 inch from the edge, it will turn black. I will have to experiment with some thicker (.003) copper that I have laying around. -Jolly

Barbara Muth · Post by **Barbara Muth** » Tue Jan 20, 2004 8:27 am

Another questions Judy.

Was it close to the edge of your glass? If so, is your thicker copper usually close to the edge?

When I look at glass sadwiched copper pieces, I have noticed that the edges of the glass are more likely to oxidize than the center which usually turns that gorgeous burgundy red color. I suppose this would lend credence to the theory that somehow you left an opening for the oxygen.

Several years ago, when I was making my first batch of magnets, (encased silver leaf) I had several maggies where the silver oxidized to a whole spectrum of lovely colors, not just the silver stain I was accustomed to seeing. In each case, the magnet had not completely sealed in the silver.

Barbara

Jackie Beckman · Post by **Jackie Beckman** » Tue Jan 20, 2004 9:23 am

I haven't done too much work with copper, but I usually get a great reddish color-

copper tiles:

http://dell.shutterfly.com/osi.jsp?i=67 ... 41e20e84f1

Judy Schnabel · Post by **Judy Schnabel** » Tue Jan 20, 2004 10:15 am

Hi All,

After reading the comments, I thought the answer was that the copper that turned black was very close to the edge. My fish that turned nice reddish color was centered between two layers of float.

This theory is kind of blown now by looking at Jackie's tiles. The copper in the tiles looks as though it's right to the edge of each of them.

Jackie, how thin was the copper shown in your tiles?

Got to do more experimenting with the thin copper.

Judy

Jackie Beckman · Post by **Jackie Beckman** » Tue Jan 20, 2004 8:22 pm

This theory is kind of blown now by looking at Jackie's tiles. The copper in the tiles looks as though it's right to the edge of each of them.

Jackie, how thin was the copper shown in your tiles?

Hi Judy, I got your email, but since you posted here too I'll answer here incase anyone else wonders the same thing. The copper does not go ALL the way to the edge or the glass couldn't fuse together. About 3/8" away from the edge.

From the email you asked if the base glass was black. No. I've done some for someone using black and I like it much better, but for these I just used float - nice-n-cheap. I've also done some on red, and believe it or not, that looks the best. Not just because I love red, but because the outlined look, where there is no copper, just goes away.

Lastly, I'm not sure the exact thickness of the copper - it's a little thicker than heavy-duty reynold's wrap. Lotta help that was, right?

Kathie Karancz · Post by **Kathie Karancz** » Wed Jan 21, 2004 2:15 pm

Hey Jackie: Love the tiles - nice and simple but the affect is great. Have you experimented with painting at all on the copper prior to putting the top layer of glass on??? If so, what did you use and what product? I tried using thomson enamels and the colours just went black on me. Any suggestions???
Hope your nice and warm (cuz I'm freezing!!!)

jolly · Post by **jolly** » Wed Jan 21, 2004 2:18 pm

Some of the latest things I am experimenting with inserting copper. Notice I am using the black for bordering.
http://f2.pg.photos.yahoo.com/ph/jollyw ... /my_photos

Kathie Karancz · Post by **Kathie Karancz** » Wed Jan 21, 2004 2:22 pm

Jolly: Rats!!! I can't open and see (it's saying it doesn't exist... is it me??)

Judy Schnabel · Post by **Judy Schnabel** » Wed Jan 21, 2004 2:35 pm

Kathy,

I'm not Jackie, but I was experimenting with the Pearl Ex micas from Michael's.

I did large and small pieces of copper with all the Pearl Ex micas. These experiments were not "pictures" just blotches of paint to see their reaction with the copper.

I probably could take some pictures and post them on my picture trail album, keeping in mind my copper did turn black.

Judy

Kathie Karancz · Post by **Kathie Karancz** » Wed Jan 21, 2004 2:46 pm

Hey Judy: Thanks for writing... I don't care about pictures - what I'm curious about is whether you can put colour on the copper, sandwich it with the glass and then get the copper to turn that great red colour with the colour of the drawing (or whatever) staying on the copper and not turning black (the colour that is). Why did your copper turn black??? Did you not sandwich it between glass??? Just curious. So my understanding is that you put the mica right on the copper and fired away??

Jackie Beckman · Post by **Jackie Beckman** » Wed Jan 21, 2004 2:49 pm

Kathie Karancz wrote:Hey Judy: Thanks for writing... I don't care about pictures - what I'm curious about is whether you can put colour on the copper, sandwich it with the glass and then get the copper to turn that great red colour with the colour of the drawing (or whatever) staying on the copper and not turning black (the colour that is). Why did your copper turn black??? Did you not sandwich it between glass??? Just curious. So my understanding is that you put the mica right on the copper and fired away??

Yes you can - I used black Paradise Paints on the copper for some of the tiles. I can post a picture later if you'd like. Just let the paint dry all the way before capping it. I let mine dry overnight and it was fine, but this IS AZ - might be longer for you.

Jackie

Patti Rohwer-Nutter · Post by **Patti Rohwer-Nutter** » Wed Jan 21, 2004 2:57 pm

Way cool Jolly, especially #2 and #6! Are those just float and copper, or have you added something else to the mix? I love the range of colors you got.

I'm confused about the shards - do you place them between the layers at the edge? Wouldn't that allow oxidation all the way throughout, leaving a all-black tile?

How big are these? Do you get more variegation over a large piece?

Thanks,

Patti

Kathie Karancz · Post by **Kathie Karancz** » Wed Jan 21, 2004 2:58 pm

Hey Jackie: What I'm trying to do is not have black but a colour on the copper. I have tried the Paradise paint (yellow) and it turned black. I am wondering if there is another product out there that would maintain it's colour under the cap and after firing????