Here are the results with the Silver metal clay. These didn't need quite as much finishing work to them.
After my precious metal clay pieces dried thoroughly I spent a few hours cleaning them up. What I found most useful was 400 and 600 grit wet/dry sandpaper. I used the 400 first, then the 600 for some extra fine cleanup. I was really quite surprised and happy with the results of the copper clay (I had such a frustrating time with it while wet that my expectations were very low - you can read about that in part 3 here). The smallest piece broke and I figured it wasn't worth trying to repair (less than 1 cm square).
I left some rough bumpy places in hopes of a rustic, organic or nugget look (bottom left and bottom middle), however, the back sides are smooth. And I attempted to carve hearts in the two circles. I am very interested to see how they come out of the kiln. These are all thick pieces (approx. 2-4mm) and there is no way that they could be torch fired.
Here are the results with the Silver metal clay. These didn't need quite as much finishing work to them.
The letter E I made broke. I haven't decided if it is worth trying to fix. It seems too cracked and is a bit warped.
The next step is firing in the kiln. I've been a little hesitant to fire up my kiln to 1800 degrees in this heat that we have been having, but I will do it soon and post pictures of the results. For firing the copper, I am going to follow these steps by Pam East on the Metal Clay Guru Website, which is a great resource for those who work with precious metal clay.
So, I haven't touched my metal clay for six months (but I've had a good excuse - I am pregnant with twins). I've been telling myself that once I have these babies, I won't have time for who knows how long, so I finally set aside time for it the other day.
I had a large lump (probably 30-35 grams) of copper clay left over from my first time using it. I stored the clay in plastic wrap, followed by two zip seal bags with a moist paper towel (to provide a little humidity). The outer layer of the clay was pretty dry. I decided the night before that I was going to use it the following day, so I opened it up and sprayed it with some water, wrapped it back up and let it sit overnight. I am glad I did this because it was softer the next day. However it was still so difficult to work with and I vowed that in the future I would never open a package of clay, without intending to use all of it up. When purchasing clay, it is helpful to consider that It may be a better value to purchase the larger package of clay, but the second you open the package, the clay begins to dry out and becomes harder and harder to work with as time goes by - at least in the dry desert climate that I live in.
Lesson 1: I will never open a package of metal clay, without intending to use it all up in one sitting.
Here is a picture to show you (this is silver clay by the way). From a 20 gram package of clay, these are the first and last pieces of the clay. I made the circle first and by the time I used up all 20 grams, I formed this lumpy dry oval as I couldn't get the clay to do anything nicer. The circle is nice and smooth, while the oval is cracked and lumpy. And I did attempt to add moisture to it many times and covered it up while I was working with another piece.
Lesson 2: The longer the clay is exposed to air and the more you work with it, the harder it is to get it to do anything.
Back to the copper clay - I kept attempting to roll it out, shape or make "snakes" with it. I couldn't get it to do anything. It was very frustraiting and I kept asking myself why I invested so much money into this new hobby of mine. I could also feel small pieces of very hard and dry clay in with the moist clay. I hope those dry pieces won't be a problem during the firing process. After 20 minutes or so, I finally gave up attempting to make anything decent from the wet clay, and formed these lumps, that I hoped I would be able to shape when dry. Or if nothing better, I thought they would make a good test run in my new kiln.
I knew that if I stopped here (ending on such a bad note) that I would never want to pick up the metal clay again, so I opened up my smallest package of silver clay (20 grams) that I had on hand. The fresh clay was so much easier to work with and remembered the fun I had the last time I used metal clay. However, it also began to dry out quickly as I mentioned above.
Here are the pieces left how they dried. Watch for another post about how the cleaning up and shaping of both the copper and metal clay goes, in addition to the firing.
Cleaning Up Your Fired Copper Clay Pieces
After firing the metal clay pieces it is time to burnish or polish them. They still look like clay until you have polished them. There are many ways to polish - wire brushes, spoon, polishing papers (very fine sand paper), steel wool, agate burnishers and rock tumblers to name a few.
Fired, quenched and unpickled
To Pickle Or Not To Pickle?
Everything I read about torch firing copper clay said that you had to pickle the piece after torching. I spent about 45 dollars purchasing the necessary pickle equipment (copper tongs and pickle pot, sodium bi-sulfate compound). However, my torched pieces had very little fire scale on them and I did not pickle them, as I didn't feel it was necessary. Plus, I usually like to patina or antique them anyways, so the little bit of fire scale there, will just add to the antiqued look.
Please note: As I fired the pieces, I kept the torch on the piece as I picked it up with my pliers and continued to heat the piece until I submersed the copper into my quenching water. Keeping the heat on the pieces as long as you can will reduce the amount of fire scale they get.
Lesson 1: It is not mandatory to pickle torched copper clay.
Then I read how toxic pickle solutions are - how they need to disposed of properly at a hazardous waste facility, how it can eat holes in your clothing if splashed upon, burns skin etc.... I have a toddler in my house, do I really want this stuff around? There are a couple more environmentally friendly alternatives to sodium bi-sulfate compound, such as citric acid, that I will try before using the traditional pickle.
Burnishing With A Wire Brush
Some people suggest using a steel brush while others suggest a brass brush. I tried both, and found that the brass brush turned my copper pieces a brassy gold color. The steel seemed to bring out the copper color, so that is what I continued to use. In the photograph below, the small circle was burnished with the brass brush, the flower with the steel brush and the heart is only have burnished, to show you the difference. After I finished these pieces, I read someone who suggested brushing under running water, with a little soap. These pieces were brushed dry, next time I will try brushing with water.
Lesson 2: For copper burnishing, begin with a steel brush.
Next I used 0000 grade steel wool. I highly suggest using a ring clamp to hold your piece (if it is flat) while using the brush and steel wool. Those two polishing tools can really wreak havoc on your fingertips.
Lesson 3: Use your ring clamp.
I used liver of sulfur gel to patina my pieces. I let some of the pieces oxidize longer than the others. I wanted them all to be different. I also wanted to experiment to see how this copper clay took the patina. For more information on liver of sulfur patinas, see this article here.
Here are my pieces after being in the rock tumbler (with stainless steel shot) for two hours. I am happy with the result - not bad for my first attempt, yet far from perfect. But I have learned a lot in the process. Hopefully you can learn a little from my mistakes as well.
The heart in the top left corner did not receive a liver of sulfur patina. The others did, for varying lengths of time. The ring at the bottom is of pure copper wire, just to illustrate the color differences.
I would love to hear what you think!
I finally took the plunge and spent over $300 in tools and supplies to work with metal clay. I am documenting my experiences, in hopes that my mistakes and lessons learned might be useful to others thinking about or beginning to use metal clay. This will make most sense if you have a basic understanding of metal clay.
Lesson 1: This stuff is expensive (about $1.50 per gram for silver and $0.36 per gram for copper at the time I purchased it)!
I was very disappointed to see how tiny a 20gram lump of silver clay was. It is about the size of a stack of three quarters. As copper is much cheaper, I decided to experiment with it first. There is a new quick fire Copper Clay which hit the market in December. The quick fire Copper Clay can be fired with a torch. Which, is what I am doing as I don't have $800 to invest in a good kiln. Especially for something I haven't tried yet.
This is what I came up with during my first time using the clay (the two pieces on the top have been burnished, the four below have been fired). The instructions that came with the copper clay said to heat the piece (with a butane torch) until cherry red. Then to hold the temperature (keep it cherry red) for 3-5 minutes. I fired my pieces for 5 minutes each.
I began the firing process using a micro torch. However, in the middle of firing the third piece, I ran out of fuel! Aggghhh! I quickly grabbed my large blue propane torch (BerzOmatic "Fat Boy") and began using it. I decided that I liked the propane torch better, as it heated the piece much faster (and this canister of fuel has last for months). Not sure what is better for silver clay as I haven't tried that yet, but for copper clay, propane is my choice for torch firing.
Lesson 2: Use a propane torch when torch firing copper clay.
All of those pieces in the photograph above have been fired. I began the polishing process on two of them. One of which, (you've probably noticed) is broken. Before firing, as they clay dried on my candle warmer, the piece curled a bit around the edges. After firing, I took a pair of pliers and tried to flatten it out a little. SNAP! oops!
Lesson 3: Finished pieces of metal clay can break. Easily.
I have read that it is possible to fix a broken piece, but that will be a topic for another post. After a few hours trying to research what went wrong on the internet, I learned a valuable lesson about sintering metal. [If you are going to get into metal clay, you will want to read the article on that link as it is explained very well.] Basically, the metal particles in metal clay have tiny spaces between them. When fired, the pieces of metal that are touching bond together, but there is still space between, which makes the piece more susceptible to breakage. The longer the piece is held at the sintering temperature, the stronger the bond on those tiny pieces of metal will be.
lesson 4: The recommended firing times are the minimum time required to hold the piece together. There is a big difference between the minimum firing time and temperature and the ideal firing time and temperature.
So I went back and fired my unbroken pieces again for 15 minutes each. When you are swirling a torch and staring at a piece of cherry red metal, 15 minutes feels like an eternity. Especially when you have multiple pieces to fire. The ideal firing time is two hours, but that is not possible with a torch. I have no idea how much stronger my pieces will be, but I felt that 15 minutes was a big improvement over 3-5 minutes.
Lesson 5: Torch firing metal clay takes time. Have your ipod to help pass the time.