Sep 19 2010

Good News about Pearl Grey Steel, and Gradient Surfaces

This posting has two parts. Please be patient; it’s going to be long.

1. Firing Temperature of Pearl Grey Steel

No more high temperatures! It turns out that Pearl Grey Steel has the same sintering range as copper (1470°F/800°C – 1800°F/980°C). It can therefore be fired with copper and bronze in the same piece, at the low firing temperature of bronze.

How come I didn’t know this earlier? I guess I made the worst mistake one can make in research: making assumptions. I assumed that since the main ingredient in steel is iron, and iron’s melting point is so high, then the sintering temperature of Pearl Grey Steel must also be high.

How did I find out that this was not true? By mistake – which can sometimes be the best thing that happens in research. I accidentally included Pearl Grey Steel in a batch that was fired at the firing temperature of bronze, and I discovered that the Pearl Grey Steel sintered. I repeated this several times and it worked every time.

Here are some examples:

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And here is Pearl Grey Steel with bronze only:

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The firing schedule is the same as for my traditional Copper and Bronze Clay. It consists of 2 phases:

Phase I
Ramp at full speed to 1000°F/540°C (top loader); 1100°F/590°C (front loader)
Hold for 30 minutes to 1:00 hour, depending on the size of the pieces

Cool to room temperature. Remove ash and add more carbon if necessary.

Phase II
Ramp at full speed to 1470°F/800°C (top loader); 1520°F/830°C (Front loader)
Hold for 2:00 hours.

(I rounded off the numbers when translating them from Fahrenheit to Celsius.) Tip: once the first phase is over, take whatever box you use out of the kiln and place it outside in a shaded place, shielded from the rain.

By the way, I find this is the best firing schedule for bronze, copper, and Pearl Grey steel, whether fired by themselves or in combination with each other. With copper, too, it is unnecessary to go to high temperatures; I have had more success in sintering copper with this 2-phase schedule than with any other 1-phase schedule.

2. Gradient Surfaces

Although polymer clay is not my field of expertise, I have been studying a lot about polymer clay techniques to see if they can be adapted to metal clay. Some of them can, but with a few adjustments that are required mainly because metal clay is fired and not baked. The firing process can cause different (sometimes undesired) results when applying polymer clay techniques without these adjustments.

However, the technique for creating a gradient surface, known as Skinner Blend, can be applied in almost precisely the same way as with polymer clay. This technique produces a gradual transition from one color to another, and even to a third color.

Here are some examples. Starting from copper to bronze:

Copper to Bronze

This surface, once fired and finished, immediately brought to my mind the gradient paper I use for taking my photos. So, I just hung a tiny piece of jewelry on top of it.

"Cab" on gradient vbackgrounf - front view

Cab on gradient background - front view

Back view

Back view

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This one is from steel to bronze:

Before firing

Before firing

After firing

After firing

And this one is from steel to copper to bronze:

Instructions on how to make the Skinner Blend can be found in almost any book about polymer clay.

Important note:: This technique will not work if one of the ingredients is silver or regular steel clay. I am about to start experimenting with White Bronze.


Sep 12 2010

Second Edition of My First Book, and Some New Work

The second edition of my first book: The Handbook of Metal Clay: Textures and Forms has finally gone to print and will be available by November. You can see the covers and the introduction on my Web store. Thank you for all the beautiful photos that you have sent me. I have managed to include almost all of them. I will post again when the book is out.

You can pre-order the book now. There is a discount of 25% for a minimum order of 12. Please see details here.

On another note, I’d like to share with you some of the work that I’ve been doing lately. Most of it has to do with caning and mokume gane effects.

The following are hollow forms. The third one is a combination of copper and White Bronze. The fourth photo shows solid bi-cone spherical beads.

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Mokume mascara

Oval  cab

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Ball and bicpne

The following demonstrate wood grain effects.

Woodgrain tube Earrings

Woodgrain rectangular earrings

Woodgrain lentils

Woodgrain bracelet

And these are striped designs:

Striped dome earrings

Striped rock

Striped-squares

In the last four you can see a third, pinkish color. This is created by mixing bronze and copper clay.

And finally, two more magnetic clasps made from Pearl Grey Steel and bronze and copper.

Magnetic clasp

I’ve been asked whether I am going to teach some of these techniques in my next workshops. Absolutely – some techniques I am still working on, but I will certainly teach what I feel confident about.


Sep 1 2010

An Update to My Travel-Teaching Schedule

Three classes have been added to my travel-teaching schedule in 2010-2011.

November 15-16, 2010, Amado Territory Ranch, Arizona (30 miles south of Tuscon)
Contact: Expressive Art Studio

March 18-19, 2011, PMC Guild Chapter, Columbus, Ohio.
Contact: Carole Bucklew, BucklewC@xenos.org

April 8-10, 2011, Local Metal Clay Guilds and Chapters, Chicago, Illinois.
Contact: Patricia Weikersheimer, pbweikersheimer@yahoo.com

The file “Hadar’s Travel-Teaching Schedule” on the right pane of the blog has been updated with these changes.