Friday, December 28, 2012

Firing Copper Clay

I pulled an old post from my blog to share with you today. For those of you unfamiliar with Copper Clay I thought you might enjoy seeing the process.

Copper firing, basically from start to finish.
 There can be variations in the firing schedule of pmc, this is the one I've been using on my Copper work and it's worked well for me.

Here are the pieces all molded and shaped and filed and ready for the kiln.

First phase of firing is open shelf, 15 minutes at about 650 degrees.

This is what they look like after open shelf firing. All the black stuff comes off during the second Phase.

Then they get packed in Carbon for the second phase, 1700 degrees for about 3 hours.
Here they are all layered in the carbon and loaded in to the kiln.

3 hours later...

I let the container cool off to under 500 degrees before I attempt to remove it. Then I let it sit until it's much cooler. Below it's still hot enough I need to use my heavy duty welding gloves to handle it.

There they are peeking out of the carbon when I pour it out of the container.

Used my gloves and a metal spoon to start to unearth the pieces. Everything cools off rather quickly from here and by the time I've found the large pieces I can usually start using my bare hand to find the smaller ones. There are usually one or 2 that don't want to be found, so when it's completely cool I sift them through the slotted spoon back in to the container and find the stragglers.


And then...

Some of them are just about perfect out of the kiln, just a little brushing and they are good to go. Some need to be tumbled for awhile and then I usually take a torch to them to give them lovely variations in color.

So there ya go, approximately 7 hours later I have some pretty Copper goodies, not counting the time it took to get them ready for the kiln. Copper and Bronze are not quick processes.

Then some of them get listed on Etsy!

I actually don't do the open shelf firing these days and go straight in to the carbon.
Seems to work well for me. It's still a very long firing process, from start to finish about 6-7 hours. I usually fire it up before I go to bed and it's cool enough to remove in the morning.



  1. Great post. Thank you for sharing. I tried working with copper pmc a couple of years ago. It didn't work out for me. My kiln couldn't get to the maximum firing temp. I still have those pieces hanging around. I keep meaning to torch fire them.

  2. Most Copper Clays cannot be torch fired, they have to be fired in an oxegyn free environment which is why they are layered in carbon.

  3. Wow, I'm glad you enjoy this process Kristi, because I love your pieces. I'd be hesitant to leave it on during the night, I'm a bit paranoid on that stuff. I don't even leave the crockpot on if I'm not here. Thanks so much for sharing the process!

    1. It's out in the garage in it's own little area and on the opposite side of the house.

  4. Wow! What nice kiln -and a Long hot firing process. Thanks for sharing;)

  5. Wow, I have not really thought about all the time it takes to make such beauties. Love the hummingbird :-)

  6. I am just getting started in the PMC world. In working with copper pmc Rio Grande says you use coconut shell based carbon, what is the difference in this and just carbon as uou indicated and can either be used?

    1. There are a few different types of carbon, they all work just about the same. I use coconut shell carbon as well. I recently ordered Magic Carbon from Cooltools, hoping to get more color right out of the kiln. We'll see.

    2. I am so nervous to use my kiln for the first time, so i keep reading to learn, so i can use any type of carbon with my copper? I love the rainbow effect you get with your pieces, is it obtained just by heating with a torch and dropped into water or do you use patina. Your pieces are awesome!

  7. I enjoyed this post, Kristi! It is always so facinating to get a glimpse into the processes involved in the the creation of artisan components. Makes me appreciate them even more!

  8. I do PMC, Copper and Bronze. I love your pieces so much though, I recently ordered one of yours (and besides, copper is an all day process and I'm a little impatient). I recently purchased the Magic Carbon but I've only tried it once. I want to use it several times before I pass judgement.

  9. I've been using magic carbon. It gives the pieces a bit of antique color. But mainly I use it because it seems to fire nicer - more stable and even heat.

  10. I've been using magic carbon. It gives the pieces a bit of antique color. But mainly I use it because it seems to fire nicer - more stable and even heat.

  11. Amazing look at the firing process and yes they are all such gorgeous pieces!!!!!


We would love to hear what you have to say, please leave a comment.