Creating an Alloy by Mixing Silver Clay and Copper Clay

Quite a few disasters happened when I fired copper and silver clay together. Here is an example:

What I think may have happened, is that the copper and silver created an alloy, and the hold temperature was too high for that alloy. When you alloy two metals, the melting temperature of the alloy will be lower than the melting point of each of the pure metals constituting the alloy. For example, fine silver melts at 1760°F; copper melts at 1980°F; but sterling silver (which is a combination of 92.5% fine silver and 7.5% copper) melts at 1640°F.

However, I was curious to see what kind of an alloy can be created by actually mixing copper clay and silver clay, wet, and firing them together. I mixed copper clay and low-shrinkage silver clay.

I rolled it 3 cards thick and cut a circle, ¾” in diameter.

I fired it with a batch of copper clay, making sure there were no bronze pieces in the box.

It blistered badly, so obviously the temperature was too high. The shrinkage was about a third.

Next, I sanded it as much as I could to see what color it was.

Here it is, next to copper and bronze.

And here it is next to copper and bronze painted with Baldwin’s Patina.

The ratio I used was 6 parts copper to 4 parts silver. Other combinations probably will yield other colors. Another thing that will require some experimentation is finding the right temperature for firing these alloys.

One question I ask myself is: is the difference in colors distinct enough to justify all the effort? Another question is: Wouldn’t it be possible to achieve the same colors at significantly lower cost by using combinations of copper and bronze?


11 Responses to “Creating an Alloy by Mixing Silver Clay and Copper Clay”

  • Bobbie Rucker Says:

    It is a very pretty color, I would be interested in trying this, when you did the mixed brinze and copper, that was a pretty color, what about adding more copper than bronze in the mix?

  • Priscilla Vassão Says:

    Hadar, how about mixing a sterling silver alloy? I wonder if it would produce a stronger, yet white, silver clay…

  • Hadar Jacobson Says:

    Priscilla, it’s certainly a possibility, but the alloy will still be porous. It may not be as strong as we’d like it to be. I’d love to try, but that means trying to break a lot of test pieced from silver. I don’t think can afford it.

  • Hadar Jacobson Says:

    Bobbie,

    My next step was to mix 8 parts copper to 2 parts silver. But I’d rather do it with copper and bronze, if possible.

  • Sylvanye "Sam" Roh Says:

    Fantastic color, I can see using this combination a lot. In addition, I was not familiar with Baldwin’s Patina but after reading about it and seeing what you have accomplished with the copper and bronze samples I can’t wait to try it.

  • kim Says:

    That color looks a lot like a Japanese alloy called Shibuichi…which I THINK is silver and copper…..

  • Ann Davis Says:

    Holy Cow!! That’s pretty!! What a lot of fun..kinda stuff I love to do! Thanks Hadar!! You are constantly upping the anti!!;)-ann

  • Hadar Jacobson Says:

    Hi Kim,

    Yes, shibuishi is copper mixed with 5% – 25% silver. I am experimenting with several combinations, hope to show it soon.

  • Jenny Ekberg Says:

    Hi Hadar,
    I have a question: I would love to do a project in which I fire silver and copper clay together, with the different clays TOUCHING. I know this is tricky, normally you would have to fire the copper clay first by itself, right? How about if you fired silver clay with this kind of alloy. Would you be able to fire them together (without firing the alloy first), touching each other?
    Thanks
    Jenny, Brisbane, Australia

  • Jenny Ekberg Says:

    Thanks Hadar, that definitely answers my question! Jenny

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