Friday, April 11, 2014

White Copper Clay: A New Medium

by Staci L. Smith

White copper clay is a new product in the family of metal clays.  It is mostly copper, with some nickel added in to give it the white color.

I know there have been other white metal clays out, but for various reasons I steered clear.  The brand I purchased is the brand I am familiar with and use for bronze, copper and PMC.

Now, similar to when I started using bronze clay, there is not a lot of information out there about this product yet.  Actually, other then the instruction on the package insert, there is none.  

So of course I bought some, and thought I'd figure it out.  

Base metal clays are known for being finicky.  There is no set firing schedule that works for every clay, every kiln and every piece created.  Its a lot of learning your kiln, your beads, and adjusting the firing.  Though the package insert I believe does give you guidelines for adjusting the firing.  
White copper clay, does not.  It has one set of very simple straightforward instructions.

I set out with many questions:

You can read my initial blog post here.

Ok- so where do I start?  

Working with the White copper clay it looks mostly like traditional copper clay.

Working with it was similar to the base metal clays I use, I'd say it was a cross between copper and bronze.  Copper being easy to shape and smoother feeling, and sticking to itself nicely, bronze being more dry /firm, and not wanting to stick to itself at all.

Of course, you would think that since it was my first time working with something new I'd just make some charms and test fire them, right?  You would think......but alas, I seem to like to make things hard on myself (and honestly, I wanted to find out as much as possible right away about this medium).  

I made pieces that would be riveted together by heating ball head pins, made pieces that would get ring shanks soldered to them and make rings, attach balls with slip, ect.....  I did make some charm like things too though!

I fired them according to the instructions.  First phase is a low fire on a stainless steel mesh in the kiln.  Then you take them out and put it in carbon for the second phase.  

When I took out my pieces they were NOT white or pewter colored.  The ones on the bottom of my container (where my kiln seems to be the hottest) were covered in copper flecks, that were raised.  They were shaped like the carbon (I used magic carbon) and almost looked like they electroformed to the carbon.  so when the carbon was washed off, it left little raised metal pieces stuck to the surface.  And they were sharp too!

Most of the pieces had this.  As I got to the top pieces, there was less of it.  However, problem number 2......

They all looked rosy, or more like a bronze then a pewter color like they were supposed to come out.  And some were very mottled too, which happens with my bronze sometimes, but it cleans up well.

So I brass brushed them and tumbled them like I usually do.  They still looked bronze.  So I pickled them.  STILL looked like bronze.  So I had to get out my dremel and polish discs and grind off the surface coating, and voila!  There was that silver color.

after brass brush and tumble and grinding, you can still see the copper flecks

So, I am pretty sure they over-fired.  Its like brass, which is a mixture of copper and other metal.  When  you overheat it, the copper rises to the surface, and nothing takes it off other then grinding or polishing away that whole layer of metal.  I think that is what happened here.  However, I still don't know why I got the 3-d effect of the copper pieces bonding to the carbon.  If a reduced heat doesn't solve the problem, I may try another carbon.

So I cleaned them up with the dremel, tumbled them a little more, and was ready for test #2. 


Of course, I wanted to make a ring, and of course, it was sort of complex in shape.  I wanted two ring bands, and a small bezel, all of which required consecutive solder joins.  Well, i proved my theory of copper rising to the surface with heat, and had to grind off a layer each time I heated it!  It took forever, but it worked, and now I have a ring I LOVE.  So, it can be done, but its a lot of work and clean up, like brass.  It does however, solder well.  Very much like copper.  Takes longer to heat up, but HOLDS the heat once it gets there.  So I always let it cool before quenching.  If you quench too quickly, the piece is still so hot, the solder is still liquid and it may move or unbond before its set.  Something I learned the hard way working with BIG pieces of bronze and copper.

mid-clean up post soldering.  You can see the VERY copper looking part that wasn't cleaned up yet.  The entire white copper clay piece looked like that. (and yes, it is a messy ring, just for me, I was in a hurry)

Here it is all done though, I didn't know if it would co-operate, but I MADE it work.

Here are all the ring shapes I made

Now to wear my ring all the time and see how it wears- does it make me rashy, does it tarnish, does it NOT tarnish?  Test Test Test.  (this months Boot Camp, Fine Finishings is about putting out quality work, and quality control tips to make your work lasting and high quality!  Testing is something I cannot recommend enough!)   I cannot express how important this is before you sell new work!!!!

I also made this, which required some heat, but not as much as solder, and this cleaned up much easier, no grinding or sanding required.  Just some pickle.

Ok- antiquing the white copper clay.
I only use liver of sulfur to antique my metals.  I don't like to use anything that is really strong in my house.  even my pickle solution is very mild.  I know that nickel silver is REALLY hard to antique, and haven't had success doing it with LOS.  
So I slathered on some really strong LOS gel, let it sit for 10 minutes or so, and nothing.   So I took it and rinsed it with piping hot water.  It instantly turned all kinds of colors and then darkened. 

Ahhh.......this was key for me.  I would not use a silver toned product that could not be antiqued!!!!

Then I just polished with a silver polish cloth like I normally do, and I was a happy girl!

Now I need to see if a sealer is required. I don't want it to keep darkening like bronze can.  Maybe it will be a slow oxidation like silver.  Maybe it won't oxidize at all?  I can't wait to find out.

I will be doing yet another follow up post when I try to fire the remaining pieces at a lower temperature.  

I hope all my experimentation helps someone else.  My kiln actually requires me to fire my fast fire bronze at a little bit of a higher, if this does better lower, that is really odd.  Stay tuned!!!!!!!!!!!!!!


Rising Designs said...

Thanks for your helpful and generous post!!

Erika said...

I kind of liked the coppery flecks on the nickel. It had it's own rustic look. But your finished products looked beautiful (love the ammonite disc!)
Your ring turned out gorgeous!

Artisan Beads Plus said...

I can't wait to find out either! What a process!!!! You are right about always practicing and getting to know your medium before selling. There is nothing that can replace time and practice!!!!
Great post :) and I love the ring!

Lela said...

Thanks for the review, Stacy. This is very helpful!

Barry said...

Stacy - well done - always good to see someone ready to take the risks. Thanks. B

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