Wednesday, November 18, 2009

PMC or Art Clay Silver (Fine Silver Clays)

Any one of the fine silver clays mentioned above can be fire successfully in the MicroKiln.  Firings have been conducted with and without stones and glass.  If you are using glass in your fine silver clay design you must pre-fire the glass to the desired shaped before setting it into the clay.  I realize this sounds like a common sense thing to do, but you would be surprised at the number of people who ask me about firing glass cabs and beads with fine silver clay.

Below are simple designs using PMC and Art Clay Silver (not mixed together) with and without a glass cab.  Both were fired in the MicroKiln; however, ones without glass were fired at a different time using an entirely different firing schedule.

The key to having a successful fine silver clay firing is the sintering.  Anyone can fire fine silver clay, but if it is not sintered it is not considered a successful firing and thus break due to its weakness.  Sintering to me is the process of fusing (melting) silver particles together to form a solid mass that is very strong yet can be bent without breaking.  Yes, a sintered piece can be broken but that would be considered a deliberate break.  Any object that can flex with enough bending will eventually break.


  1. Can you fire Bronze Clay or Copper Clay in the microwave kiln?

  2. No, you cannot fire (sinter) Bronze Clay or Copper Clay that requires the use of carbon in the microwave kiln today however; I am in the process of testing the NEW COPPER CLAY.

    One has been created by Art Clay and another by Hadar Jacobson; neither requiring the use of carbon and the extra tools.

    I will post my results as soon as my testing is completed.

  3. I'm getting a lot of questions from people who have seen this class advertised at Bead and Button, asking how it is possible to fire metal in a microwave.

    I admit that I can't even fathom it; can you point me to a web page that can explain what temperatures are achieved, and for how long they can be held, and why the metal doesn't simply arc and spark in the oven? It's a mystery to me, but I'd love to learn what you are doing.

  4. Hello Kate, my response to your post can be found under, "Questions & Answers Part 5. Putting in a Q & A section offers everyone an opportunity to see it.

  5. Hello Kate,

    In response to your questions/comments let me address them one at a time as follows:
    Q = Question
    A = Answer
    C = Comment
    R = Response

    Q: How is the microwave firing any better than a torch firing?
    A: The microwave kiln was primarily created to fuse glass, enamel copper and fire ceramic bisque. Since its inception those like myself who are familiar with PMC or Art Clay Silver have taken the use of this unique piece of equipment to another level. Through all of my testing with and without inclusions of glass, stones, I have perfected a firing schedule that will allow silver clay to sinter. If a person is only wanting to fire metal clay than the choice would be a torch, but if they wanted to incorporate glass in their design than they would need the microwave kiln.

    C: The firings do pollute the microwave, so you really need a separate oven for it, and then you need to buy the saggar, which has a tiny firing chamber.
    R: Engineers who design the microwave kiln and writers of their documentation did not take into account that fiber paper and kiln wash does pollute the microwave oven and therefore tell individuals that it is okay to use the same oven. I always recommend a separate oven just for that reason and you are absolutely right.
    Q: The saggar in this case is the microwave kiln itself and that is what is needed to fire jewelry design items in a microwave oven. The microwave kiln I distribute known as the Microkiln, will accommodate up to (7) 1" square glass designs in a single firing. There are much larger microwave kilns but they are not being sold in the US today.

    C: I am having trouble comprehending why this is .... useful
    R: It is only useful if you want to do some of the techniques mentioned above and cannot afford a glass/ceramic kiln or just don't want to make that type of investment at this time.

    Q: What is your annealing process for fusing glass?
    A: I have a step-down schedule (annealing schedule) that I use that incorporates the use of the microwave oven's power levels in conjunctions with the appropriate allotted time in minutes and seconds. The holding time is also based on the thickness, size and type of glass being fused and whether or not it is being incorporated into metal clay.

    C: I'm not grasping why this is a good idea.
    R: It is only a good idea if you need a kiln to do some of the techniques mentioned earlier and can't afford a "real kiln." If someone is just wanting to fire metal clay without glass or sensitive firing inclusion than a torch is the way to go unless they are affair of using a torch. I have a few students that they are their spouse will not allow them to have a torch in the house.

    I hope the information I have provided helps. The microwave kiln has gotten such a bad rap over the past two years do to a lack of knowledge as to how to effectively use it to achieve successful results and I just want to make sure that if someone is going to use that they know its limitations as well as benefits. I am constantly testing it with different types of materials and as I mentioned earlier, was successful this past week in sintering the new Art Clay Copper.

  6. Thanks much for your time, Sam- I enjoyed our email correspondence. Although I still don't really grasp the place the microwave kiln has in this arena, I'm impressed by your dedication, and your willingness to talk about the product.

  7. Happy New Year Kate!

    Thank you for the kind words. I thoroughly enjoyed our email correspondence as well and I look forward to meeting you at Bead & Button in June.

  8. it was a wonderful chance to visit this kind of site and I am happy to know. thank you so much for giving us a chance to have this opportunity..
    Indian Bridal Jewellery

    1. Thank you Maria for your wonderful comment. I have been away for awhile as you can tell but ready to release my new website and start updating the blog as well.

      Hope this post finds you doing great.

  9. These ovens are extraordinary for anything that fits in them.

  10. Emily, you are absolutely right. Hope you are having a wonderful time creating.

  11. So pmc can work in the kiln, awsome to know this...what brand do you recommend i hoped nit to have to buy two diffrent products for the same work mentioned anove whether its with or without is really helpful to know the schedule and i will be buying my kiln shortly.

    1. Any silver metal clay, Art Clay Copper and that is it. Sorry, the schedule is only provided to students I teach or who purchase my Metal Clay & Glass Mini MicroKiln kit. I will be publishing next month an ebook for use with other Mini kiln brands like that of Fuseworks, etc.

  12. What kind of glass cannot be used in the kiln?

  13. Not any that I know of except for possibly Safety/Tempered Glass; however there are people who have fired it in both a regular glass kiln as well as a MWK; I have not.

  14. Do you know if earthernware clay can be used for the mwk? Its low fire just want to make a memorial pemdant for my dog. Thanks. How much do you sell your kilns for and how much are the classes? Sam

  15. I don't recommend it because it is low fire. The microwave oven will kiln will heat up to 1650 degrees and you have to be able to monitor the glass. Were you planning on putting frit or chunks of glass in the earthenware piece you would be using as a mold? If yes, you will have to fire it up high in order to completely melt the glass in the MWK. Use a high fire ceramic mold and even then it has to be coated with kiln wash or boric nitrate.

    The MW kilns I sell come in three sizes. Please checkout my website here:

    Hope the information I've provided helps. "Sam"

  16. How long do you recommend for the firing times for silver clay,I can't seem to find a definitive answer,there aren't many mentions of how long it should be in or if it requires more than one,thanks in advance :)