Convergent Series

learning, using & teaching metal clay, and other aspects of life

Trying Art Clay Copper (Post #9 of ?)

Posted by C Scheftic on 2011/03/20

[All images in this post are composites that show both sides of the same pieces. One side of each set is to the left; the other, to the right. Clicking on any image should open a new window where you can see a larger version of it if you want.]

Four more hours in simmering pickle, and over an hour of concentrated dental-picking later, and they’re still not done!!! In addition to some remaining firescale, they still all need to be hand-polished and such. I will admit it: I am getting kinda tired of these 15 little copper pieces.

If one reason to use copper (aside from its lovely color, of course) is to help keep down the price of my work as silver prices soar, working with this copper this way isn’t looking promising. Yes, the raw material costs less, but the difference is eaten up by the hours (of my time) that will be required after firing. Yes, I can do other productive work while pieces just sit in the pickle. Yes, I’m still learning at this point, so I’ll likely find ways to speed up with trial and practice. But right now, what I have invested in these is far more than what I could ever sell them for had they been silver. And copper sells for less. I can picture getting the copper-work down to the same cost, to me, as it’d’ve been had I worked in silver. I’m having trouble picturing how to get the cost (materials + time) to come in at less. (And, yes, Art Clay Copper can also be fired in activated carbon, like the other copper clays, which should eliminate some of the firescale problems … but the point of trying it was to see if I could avoid the various other issues in using that technique.)

The two fish — the pieces that caused the whole episode of having to start a second packet of clay during the construction phase — have cleaned up nicely. The fan still needs some clean-up on the front, and the ginkgo needs a little on the back. But these four are in pretty good shape. The end of the work on them seems to be in sight.

The pair of matching wedding-love medallions don’t match. In my last post I noted the huge air-induced bubble on the one at the top. It’s a kind of nice effect; my only disappointment with it is that the other one didn’t react the same way! Both heart-sides cleaned up well, but dental picking was key there. (The top one was also polished with a Dremel tool. That didn’t help with the firescale, at least not via the attachments I tried, but it’s why that one looks a bit shinier than any of the others for now.) The bells still need a bit of work. Note that the bell that’s on the convex side of the bubble dome cleaned up a bit better than did the one that’s still flat. (Yet another reason I wish both had bubbled!)

The other pair of disks show something similar. They each have the same intricate texture on one side, and the one that’s on the convex side of the domed piece cleaned up well. The other one, on a flat piece, is going to require a good bit more cleaning: whether that means going back in the pickle or being attacked with more hand tools has not yet been decided!

Of the next five, the little leaf-shapes are in the best shape. The other three all still have a lot of firescale, on one side or the other. On the paisley shape, the most black is on the side that was facing up on the firing shelf, so that makes some sense to me. I’m sorry to see, however, that the patch I had made to the little ding the piece suffered while drying is one of the bits that popped off. (Please, can we just have the firescale pop off? What’s this with losing other bits as well!) On the butterfly, the most black remains on the side that was fired down, which is not how it’s supposed to work. Same thing on the long oblong shape: the blackest side was fired face-down. I can almost understand it for that piece: the face that was down was not really flat, so some oxygenated air could have slipped underneath. But it also disappoints because in the “popping off” action, a small area near the top (right edge, just under the smooth area at the top of the textured section) now has a small hole in it.

But the biggest disappointment is this last little pair. Even after almost seven hours in hot pickle, the black just will not come off them. And they totally defy the theory of less firescale on the face-down side, because the dense black — up in the indentations on the side that doesn’t have the little “snake” — is on the side that was facing the kiln shelf. I tried picking at them, just to see if it’d work, and it did not. These were meant to be used in an inexpensive little pair of earrings, and it is not worth my time to pick at them any more. They’re going to sit in the pickle until they clear themselves up, or they just disintegrate in the acid.

But I’m too tired to think about them any more right now. Polishing remans .. both to be done, and to be reported on.

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4 Responses to “Trying Art Clay Copper (Post #9 of ?)”

  1. Jane said

    Did you ever solve your pickling problems? I just started with metal clay (Hadar’s copper and white bronze), and the pieces are completely covered in fire scale that I cannot get off unless I file away all my texture! I’m so frustrated. I tried a couple hours in pickle (I forget which kind), but it made no difference at all. If you’ve found some way to pickle off the ugly, can you please e-mail me? Thanks so much!
    aliasjanedoe@hotmail.com

    • C Scheftic said

      Hi, Jane:

      The only time I tried pickle with copper clay was with these Art Clay Copper pieces, because it’s what seemed to be “recommended” for that product.

      I have never pickled pieces made from any of Hadar’s clays. Usually, I’ll just “clean them up” with the 3M radial bristle polishing disks. (Do you know those? They fit onto rotary tools, like a Foredom or Dremel, for example.) Depending on the piece, the texture, the overall design, I may use other rotary tool attachments (e.g., a silicone wheel or sandpaper) but those are more “aggressive” at removing metal so I’m very selective about where I’ll use those.

      FWIW, when Hadar was here recently, she also said she does not pickle products made with metal clays (her own or any of the others).

      I’d suggest you start by trying the 3M radial bristle disks: Do report back whether they work for you!

      -cs

  2. JeanT said

    I saw an article that suggested torch-firing the firescale off the fired pieces and quenching quickly. If so, why, fire in the kiln at all? Why not just torch fire in the first place?

    I had a very difficult time conditioning Art Clay Copper. Art Clay Silver 650 Slow Dry is wonderful to work with. I am beginning to think like you – why bother to do copper. More labor in the wet (malleable) state, more cracking, couldn’t get a good coil without it breaking, harder to join pieces, firescale to deal with, etc.

    My friend, Cheryl, has tried BronzClay and is having good success with it. She says the FastFire is not quite as easy to work with as the regular, but both have a nice, creamy consistency. This does require activated charcoal in a steel firing pan, though. I’ve ordered some from from Rio Grande, due in this Friday. We’ll see how that goes.

    • C Scheftic said

      Several things…in the order in which you raised them:

      If you torch fire for the entire burnout and sintering process, you will end up with more firescale to deal with than if you kiln-fire and then quickly torch and quench. And if you work in any quantity, torch-firing each piece individually will eventually become rather tedious.

      I do still work with copper! Just not this copper this way. My favorite copper clay, at the moment anyway, comes from Hadar Jacobson. I also like her bronze clay. You have to mix the clay from powder, but her copper in particular then feels like silk in your fingers! It is easy to work with, dry-clay pieces join easily, fired items polish up beautifully, etc.

      It can be a bit tricky at first to fire any of the base-metal clays (in activated carbon in some sort of vessel) but, once you get the hang of it, then it’s lots of fun. Getting the hang of it does involve understanding how the firing process involves both burning off the binder and getting the metal to sinter. It’s the same process as with the precious metals (silver, gold), but getting all the variables just right is trickier! Start with simple test pieces, and have fun exploring!

      -cs

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