Wednesday, December 11, 2013

CopprClay First Firing

Oddly enough, after braving my first firing with BronzClay, I was still very nervous about firing CopprClay.  Maybe because of the high temperature, or the shorter firing schedules I found...I don't know.  I ran a test today and found out I had nothing to be nervous about.  I used the two part firing schedule suggested by Wanaree Tanner, you can find her PDF with tons of useful information for top load and front load kilns on her bog post HERE.  I did alter it a bit because two of my pieces were rather thick.  I did not want them to warp, so insead of a 1100 degree F ramp, I used a 700 degree rate.  I also fired some test strips, but made them pretty and drilled them just in case they turned out okay (which they did).  

Here's the schedule I used.

Part 1:  On fiber blanket placed on top of ceramic spacers.  Kiln vented on top (cone removed).
Rate: 550 degrees F/hour
Final temp: 550
Hold time: 15 minutes

Part 2:  In steel container on ceramic spacers with coconut carbon.
Rate: 700 degrees F/hour
Final temp: 1750
Hold: 3 hours

Here are the pieces before firing.  The textures are made with plates from Cool Tools, except for the back of the test strips which were carved with a Dockyard V gouge.  I use Cool Slip to keep the clay from sticking to the texture plated. 

I didn't get a picture between the first part and the second, but here are the pieces straight out of the kiln.

They fired mostly just right with little oxidation or blemish, except for a spot in the middle of the back of the medallion and a tiny spot on the back of the rose.  These spots almost blistered a bit and looked a deep rosy color.  There were also some pieces of carbon embedded into the texture of the medallion.  Next time I will place a bit of ceramic fiber to cover the texture and lower the temperature of the kiln a bit.  I plan on ordering some steel mesh to wrap detailed pieces and a ceramic firing pan to regulate the temperature inside the firing container.  That will also allow me to lower the temperature of the kiln a bit.  (All these troubleshooting tips I discovered from the PDF by Wanaree that I referenced above).    

The pieces after a quick brush over with a steel brush and a bit of burnishing.  I also hammered the test strips out a bit, they developed a bit of curve in the container.

You can see the texture on the back of the medallion is improved in the next photo.  I hammered it a bit to make sure the piece had fully sintered (which it had), and found that it evened out the texture a good bit.  The little black pocks from the carbon are still kinda noticeable.

I really enjoyed working with the CopprClay so far, and found the firing process to be pretty simple.  I can't wait to try some patinas out on these shiny little pieces.  I did turn the test pieces into a pair of earrings (with a bit of alcohol ink to enhance the texture), and I will be giving them away tomorrow.  So be on the lookout for a long overdue Native Bloom giveaway.    

No comments:

Post a Comment