Monday, January 25, 2010

Prometheus Bronze Clay - No Carbon Required

YES, this is the new bronze clay that I spoke about in my earlier post that I plan on testing using the MicroKiln (microwave kiln) as soon as it arrives. 

This  is a rapid and low fire bronze clay that was developed in Turkey and although not yet available in the US you can purchase it directly and shipping is FREE for a short period of time.

Several metal clay artist who have tested it using a conventional kiln or torch have had fantastic results.  It sinters via a torch in 5 minutes and conventional kiln in 30 minutes at 700C.

Prometheus™ Bronze Clay
  • -can be stored at room temperature

  • -does not stick to hands at normal consistency

  • -gives you long working time by its slow drying character

  • -shrinks only 7-9 %

  • -does not need long firing hours

  • -does not need high firing temperatures

  • -does not need a firing pan or activated carbon

  • -does not need large and programmable kilns

  • Can't wait to test it and will provide you pictures of my first designs created using the MicroKiln so stay tuned.......


    1. I am so happy to discovere your blog.
      I have mickroKlin but really didn't know what I can do with it.
      your Blog is full info and ideas!
      Thank you again!!!
      I am russian living in UK and sometimes find usefull and clear information is a big problem. Can you let me know how I can find produser of this clay and try to buy it directly from them?
      Thank you very mach!

    2. Hello Kat, so happy you found my blog and the advantages of using the microwave kiln. In respect to the Prometheus™ Bronze Clay and now they have a copper one; you can purchase it directly from them at

      In my testing this particular clay did not meet the standards I set forth in testing in the microwave kiln but is great in regular kilns. The best metal clays for the microwave today are: Art Clay Silver, Art Clay Copper and PMC.

      If you have any questions, please do not hesitate to contact me; I will be more than happy to assist you in anyway I can.


    3. This past weekend I had the opportunity to work with the new Prometheus Bronze Clay and I must say I am NOT impressed. Yes, I must admit we were drawn to the short fire schedule, but the product is inferior to the current products on the market in ALL other regards.

      To start, the clay is very granular – even coarse, and surprisingly too elastic. It doesn't hold a clean texture. The design almost seems to fall back into the clay as you are looking at it. You cannot even lift it from your work surface to place on a candle warmer without the clay stretching and your design distorting. And it doesn’t appear to like a dehydrator because the cracking is uncontrollable. Repairing the cracks is futile because the repair doesn’t seem to meld when fired. The clay is so coarse that you cannot even get a smooth surface in the green ware state.

      It did fire in 30 minutes – however, all the joints broke and there were invisible lines within the clay that created unforeseen stress cracks upon quenching. The fired color is NOT the “golden” color that we Americans think of as bronze – it’s more of a rose gold color – perhaps a high copper content? It’s an attractive color, but not when you want a true finished bronze color.

      I gave up and threw the broken pieces in my tumbler and went home. I have yet to see if I can get a high shine after all of this. We will continue to use the current market brands for our classes and steer clear of Prometheus clay.

      Lauren T. McCarthy
      Vice President, Metal Clay ARTchitects

    4. I agree with Lauren 100% I have worked with Bronz clay and love it, this other the Promethious is like working with chewing gum. I have not been able to work the stuff with much success, it will not cut without ripping and when stamped it will not hold its shape, streaches and distorts. I hace 4 more 200 gram packages I am getting rid of.

      Anthony Gallaher
      Fired Elements

    5. I am now rather confused. Having just made my first 6 pieces with Prometheus bronze clay and finding that two of them have cracked and warped, I looked for some online information. The instructions that come with the clay state it should be fired at 800c for 30 minutes but the online information says 700c. Would firing at 700c have avoided these losses? All the pieces were to the same thickness so the thinner / thicker reason given in some places is not an issue.

    6. Hello there, and thank you for writing. First I need to know that you are indeed using a microwave kiln because if this is the case you would not be firing for 30 minutes in fact no more than 13 minutes depending on the wattage of your microwave oven and the size of your microwave kiln. After responding, I will be more than happy to try and help you.

      Thanks again for your inquiry.


    7. I am glad I discovered this blog. I bought Premetheus clay, after seeing it demonstrated on a well known jewellery making channel. Not impressed. Even after firing it still feels like clay and breaks like clay. I have some in my microwave kiln now, I use it for silver clay, Art or Pmc. I 'll keep you posted.

    8. I quite like Prometheus clays. I use all brands of clay and each one has it's positives and negatives.

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