Monday, June 28, 2010

Oh, Happy Day! Copper Success!

Just look at this pile of copper lusciousness! I guess third time's the charm (no pun intended) for me to have a successful copper firing. Everything sintered, and when I drop them onto the table they make a jingling sound like coins, not the "thunk" of un-sintered metal clay.

This time I used the two-phase firing schedule recommended to me by Lora Hart. First, I fired the pieces on an open kiln shelf at 555 degrees for one hour. Then I transfered them to the firing pan with the carbon and fired them at 1670 degrees for three and a half hours. And voila! Hard, shiny copper! I'm no scientist, but I think this has something to do with the binder burning off. You metal clayers out there know that when the binder burns there's a smell, right? When I put the fresh pieces in the firing pan with carbon I never smelled that smell. When they were on the open shelf the smell started when the kiln hit about 450 degrees, just like with silver.


These from the Fern Series have a patina applied to show off the texture. I'm not sure yet if I like this. The Liver of Sulphur darkens the entire piece a little bit. The bright, shiny color right out of the tumbler looks so nice, but I don't know if that will last over time. One of the benefits of using metal clay rather than sheet metal is the opportunity for wonderful textures and when you darken the recesses the texture shows up better. With silver there's more contrast, so the jury is still out on whether to patina copper, or not. Anyone out there have an opinion on this? Please leave me a comment on this, and links to photos would be great to help me make up my mind.

6 comments:

Barbe Beaty said...

Hey Zoe!! LOVE those leaves!!!!!!!!! That firing schedule sounds like a winner! I may try the same, as my first batch was so disappointing that I didn't think I'd try the copper clay again. Glad to see that you gave it another go!

Lore said...

Fantastic !!!! I am so happy your pieces came out so nice !!! ;-)

Wendy said...

Congratulations on your successful firing. Be careful not to overload the firing pan. Rock on!!

Nicola said...

Just spent 3 fabulous days learning from Hadar Jacobsen (she has so many good tips!)
The amount you have there would've been 4 loads of firing.
So maybe that was part of the problem with the earlier things that happened....
Love the ferns (lots)
Nic xx

Vickie Hallmark said...

Beautiful! I've not been successful with copper at home yet, but then I've only tried once. I'll try this approach. Thanks for the tip!

laura said...

Hi There, gorgeous work, I love your ferns. I am new to metal clay in general and have only done two copper firings and both turned out well. I buried the dried pieces in the coconut carbon and ramped up full speed to 1000 degrees F and held for 15 minutes (the research I found recommended a longer hold if pieces are thicker) and then ramped up full speed to 1700 degrees F and held for 3 hours, both times I have acheived full sintering. Great results but talk about time consuming (I have a manual kiln)