As promised in my last posting: “What Other Things Can Be Done with One-fire Flex Clay?“, I’ve prepared projects for some of the pieces featured in the posting.
The Instruction Manual for One-fire Clays now includes two pages dedicated to One-fire Flex (pp. 7-8). Please download this updated version.
Also, here is a little video showing how flexible the new One-fire Flex clay is:
This question has been asked quite frequently. Indeed, many things can be done with the One-fire Flex clay without using the Silhouette machine. I’ve been working with it quite a bit using punches, trimming scissors, embossing folders, and mostly – simple hand tools for etching, cutting and texturing. I re-made some pieces I’ve made in the past and discovered new, easier techniques for making them. Here is what I’ve done in the past week. Still working, more to come! Projects will be posted with the launch of the new clay!
While developing the new line of One-fire Flex Clays, we decided to simplify the user interface for both our online store and our blog. The clays are now organized in groups according to their type and firing schedules. The instruction manuals are now down to three short ones: one for One-fire Clays (including the new line of Flex clays), a second for Quick-fire Clays (including Traditional/Flex clays), and a third for cold inlay powders. Each product on the store includes a description with a direct link to its respective instruction manual.
While re-organizing the store we also changed some of the products’ names. This, too, is meant to simplify things. The changes are in the One-fire category only: all clays that use a one-phase firing schedule now start with the name “One-fire” instead of “Friendly.” For your convenience, we have also created a table that lists the products whose names have changed, showing the old names and the the new ones. Please refer to the document entitled “Map of Hadar’s Clay™ Products” to see the changes and the table. (This document is also available on the right-hand pane of this blog.)
Meet One-fire Flex Low-shrinkage Steel XT:
Why do we need this one, since we already have Pearl Grey Steel?
Pearl Grey Steel shrinks much more than other clays. Here is how much it shrinks compared to copper:
This makes it hard to fire it with other clays, since the difference in shrinkage will cause the whole piece to warp. Hammering flat is not an option since Pearl Grey Steel is very hard.
Low-shrinkage Steel XT (both One-fire and One-fire Flex) shrinks very little, which makes it a good candidate for combining with other metals.
Below is the same piece with the bird blackened with patina (I sure got a lot of mileage out of this bird punch).
The piece came out a tiny bit warped. Since Low-shrinkage Steel XT is not as hard as Pearl Grey Steel, it hammered flat easily with a blow of a plastic hammer, no cracking.
This brings the number of the One-fire Flex Clays to a total of nine. They will be released in groups, one group at a time. The first group will include Dark Champagne, Brilliant Bronze, Copper, and Low-shrinkage Steel XT.
Silhouette machine people, how about a new line of One-Fire clay designed especially for the machine, no glycerin required?
White Bronze combines beautifully with other metal clays. Because of its low firing temperature I used to think that in order to do this, you had to fire the other metal first, then add White Bronze using a mechanical connection, and re-fire at the lower temperature. For example:
In the two pieces above (the ring is Friendly Brilliant Bronze and the earrings are Friendly Copper), the White Bronze is connected to itself around a tube. This is a mechanical connection and it is hard to tell if the White Bronze is actually fused to the other metals.
Recent experiments show that it actually is fused to them. The result is strong, non-brittle pieces, with two strong advantages:
- It’s hard to distinguish White Bronze color from silver
- White Bronze tarnishes less than any other metal, including silver
I fired pieces of bronze and copper first and just placed a layer of unfired White Bronze on top of each, with no mechanical connection. I always thought that there wasn’t enough pressure to make these two layers fuse. I was proven wrong! Here are some examples:
Full overlay of of White Bronze on Friendly Brilliant Bronze:
Full overlay of White Bronze over Friendly Copper:
Partial overlay of White Bronze on Friendly Copper:
In the following example only the White Bronze shows on the front of the piece; the backing is Friendly Brilliant Bronze:
What about hollow forms? This pendant and donut were constructed with Friendly Brilliant Bronze. The fired pieces were fired and covered with White Bronze, then fired again.
And these earring are two-sided; only one side was covered with White Bronze:
So far, applying White Bronze to another metal with no mechanical connection works with all other clays except for steels (these will require a mechanical connection.
- The backing layer (in a flat piece) or the core (in a hollow form) is 3-cards thick.
- Fire the pieces to the maximum temperature required for the specific clay. If distortion occurs, hammer or bend the pieces into shape.
- Add a 3-card layer of White Bronze. Make sure the White Bronze is connected to the fired metal at every point of its surface area.
- This is important: Let the the White Bronze overlay dry naturally or it will come off the backing layer. If you need to remove it in order to file or sand holes, as in the earrings shown above, wet the back of the overlay and press it into the backing layer. Then let it dry naturally. The White Bronze layer should be well bonded with the backing layer before going into the kiln.
- Fire for 2 hours at 1330°F in a brick kiln, 1380°F in a muffle kiln.
(True, this temperature is way higher than the firing temperature of White Bronze alone. However, bear in mind that the first metal used acts like a heat sink; it draws the heat away from the White Bronze, and this is why it is not over-fired.)
A few more interesting results:
The core of this hollow form is Friendly Brilliant Bronze. Two sides of the forms are covered with White Bronze, and the third side with a mokume gane layer of White Bronze and Pearl Grey Steel. It seems that this tricky combination is facilitated by the bronze backing.
And this one is still experimental: it is a solid piece of mokume gane made with Friendly Copper and White Bronze, with no backing layer or core.
It has come to my attention, through email and the Hadar’s Clay Users’ Discussion Forum, that there is some confusion regarding the products on our store and the firing process. I would like to clarify these issues, especially for new users who may be less familiar with the history of the clays.
Let’s start with the products. True, there are many clays to choose from. I remember the first time I came into a ceramic store and was overwhelmed by the variety of clays, under glazes, glazes and stains. I didn’t even know what to ask. Luckily, the case with our store is a little simpler. Almost half the clays consist of an earlier version, which personally I don’t use anymore.
You may ask: Why aren’t they just discontinued? This is simply out of respect and consideration for customers who still want them. I can absolutely relate to people who want that product which works best for them. I don’t ask why, and it not my place to change their mind. If and when these clays are no longer in demand, they will be discontinued.
These are the “older” clays:
- Quick-fire Copper
- Quick-fire Bronze
- Quick-fire Brilliant Bronze
- Quick-fire Rose Bronze
- Quick-fire Bronze XT
- Smart Bronze
- Quick-fire Steel
The Traditional/Flex Clays are specialty clays intended for making flexible clay. They are not recommended for beginners.
All the clays mentioned above require a 2-phase firing schedule, with a cooling phase between phases. The first disadvantage is the long firing schedule. The second disadvantage is that there is a high rate of cracking with these clays. This is due the the cooling phase; the clays go through temperature changes before they are strong enough to withstand them.
The clays of the new formula were intended to overcome these disadvantages. The firing schedule involves one phase only and cracks rarely occur. These are the clays:
- Friendly Copper
- Friendly Bronze
- Friendly Brilliant Bronze (closer to gold color)
- Friendly Rose Bronze (more pink than copper)
- Champagne Bronze (pale yellow)
- Dark Champagne Bronze (slightly darker and deeper than Friendly Bronze)
- White Bronze (silver color but brittle)
- White Satin (silver color and strong)
- Low-shrinkage Steel XT
- Pearl Grey Steel (the only steel clay to be used on mokume gane)
The Firing Schedules
For each of the newly-formulated clays you can find an instruction manual in the right-hand pane of my blog. Each of them is fired at a different temperature but the firing process is basically the same. The most common problem in firing metal clay is crumbling after firing. This is mostly due to poor binder burnout. To overcome this problem, here is my suggested schedule:
- Ramp at 1800°F per hour to 1000°F (in a brick kiln) or 1100°F (in a muffle kiln)
- Hold between 1:00 – 2:00 hours. This is the temperature at which the binder burns up. The longer you hold at this temperature, the better. Bigger pieces or multiple pieces need longer hold time but I rarely hold for more than 2:00 hours. Holding 2 hours for small pieces doesn’t hurt.
- Ramp at 1800F to the goal temperature for the clay.
- Hold two hours.
This firing schedule takes 4-5 hours.
There are, of course, exceptions and complications. For example, when you want to fire more than one metal in one piece. Some of these issues are discussed in the Instruction Manual and some in my books. But for now, I hope this posting is helpful as a starting point. As usual, you can always reach me by email or use the Hadar’s Clay Users’ Discussion Forum and Hadar’s Clay Accredited Teachers for any questions you have.