Microwave Kiln

My shop is finished, and now it has come time to actually USE it.  I have a MicroKiln and several bits of greenware that have been drying for over a year.  I like to make sure they are REALLY dry so they don’t explode while firing.  (OR I am lazy, or didn’t have any way t9 fire them 😀 )

Things I intend to use my microwave kiln for are:

  • Glass
  • Greenware and Glazing Ceramics
  • Enameling
  • Anything else I can think of.

The main instruction I am following for greenware is HERE.  At present there isn’t a whole lot of info on greenware/ceramics in the kiln, and I intend to document the process for myself and perhaps for others.  The above video is for Raku, but it starts as greenware in a microwave kiln.

The test subjects were a flat heart and a rectangular bead.  The little square bead has white ceramic glaze on it.  The test is to see if I need to fire in two steps A. Fire to Bisque B. Glaze/Fire again

First step is to have dried both pieces in a toaster oven for about a half hour.  (just to double check)  Ideally I would have liked to remove the light bulb in the microwave, and will at a later date so I can see the red glow from the kiln better.  The microwave is an 1100 W Microwave which means I may have to scinter in stages.  –  I think this will really be difficult to tell if it has worked.  The fired product will be brittle if it has not fired correctly.  So when you are testing your personal microwave, make some things that you don’t care how they come out so much.  I will be doing some batches of tests.

Next: Load the kiln onto both the thick shelf paper and then the fiber paper.

Next: As per the Raku video, I am going to fire for 15 minutes.  The microwave in the video is rather big, and from the manner he talks I am going to say that its probably a higher wattage microwave.  I have to assume that the glow evident from the top of the kiln at high fire means that what is inside is likely ready to stop cooking.

After about three minutes I can smell something chemical which I assume to be the white paint I put onto the square bead.  Other than that there is nothing exceptional or noisy.  I am going to run upstairs and grab some heavy duty heat resistant gloves.  On second thought, I will wait until the firing is complete .. just in case.

At about ten minutes (left) I see a light red glow from the top of the kiln.

At seven min (left) the glow is bright (and scary).  I don’t think I will need to remove the bulb at all.  I can smell that dusty smell of ceramics being fired as well.  I also notice as I watch that I can see some light where the top and bottom join.

at 4:21 I stopped the microwave.  It got to a red glow that was very intense, and the sound the microwave was making changed as well.  I didn’t want to push past this point.  Now I will take it out and let it cool for a good long time.  Once removed from the microwave, I let it sit.  It makes little crackling noises on occasion.

The kiln is made of a very delicate material and I am loathe to pry the top and bottom apart, however, they are stuck together.  I will need to wait until its cool enough to touch with my hands.

Result:  SO………. Apparently you can MELT ceramic clay.  I put in two pieces, and now they are ONE with a strip of white (where the paint was)  They are definitely not recognizable as individual pieces of ceramic.  This will take a lot more experimenting to get it right.
Picture 036

Next time:  Will go for about eight minutes.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s