Instruction Manual Updated

The instruction manual for Hadar’s Clay™ has been updated. As you can see in the right-hand pane of this blog, instead of many separate files there is now one 33-page file. On the the title page you will find the date it was last updated. I also added a table of contents, which will make it easier for you to find the specific information you need.

The manual includes:


  • A discussion about the properties of the clay in general: storage, consistency, mixing instructions, drying, shrinkage, reconstitution, repair, the firing process, firing boxes, and test firing

  • The suggested firing schedule for each clay

  • A compatibility chart: which clays can be fired together in the same piece in one firing and at what schedule

  • Instructions for programming you kiln, demonstrated on the schedules for copper and bronze

  • An article about understanding metal clay and the firing process

  • And at the end, where it’s easy to find, a quick-reference table of firing schedules.

The firing schedules have changed

Or rather, have been simplified. All clays, with 2 exceptions, can now be fired using the same firing schedule. No slow ramping is required.

Phase 1

Ramp at 1800°F/1000°C to:

1000°F/538°C (top loader brick kiln)
1100°F/593°C (front loader muffle kiln)

Hold between 0:30-1:00 hour, depending on the size and number of pieces (no harm in holding even 1:30 hours).

Cool the box and the kiln down to room temperature.

Phase 2

Ramp at 1800°F/1000°C to:

1470°F/800°C (top loader brick kiln)
1520°F/827°C (front loader muffle kiln)

Hold for 2 hours.

The exceptions:

1. When firing White Bronze, the temperature in the second phase should be lower:
1170°F/632°C (top loader brick kiln)
1250°F/677°C (front loader muffle kiln)

2. When firing Steel (regular), the temperature in the second phase should be higher:
1800°F/982°C (top loader brick kiln)
1880°F/1026°C (front loader muffle kiln)

Optional

1. Bronze alone can be fired without cooling down to room temperature.

2. Copper and Pearl Grey Steel can be fired at higher temperature:
1580°F/860°C (top loader brick kiln)
1650°F/900°C (front loader muffle kiln).


5 Responses to “Instruction Manual Updated”

  • Kenji Says:

    Thanks Hadar for this new, simplified firing schedule reference! This will really make it easier to find all the necessary information in one place. Thanks again!

    Kenji

  • julie Says:

    Just fired with bronze alone with the new method, and it didn’t work. I have a paragon , firefly top loading kiln. I use the mini kilns and carbon . Everything blistered and cracked. I was surprised to see that the carbon burned out half way down.I’ve never seen this much carbon burn out. So, I think it was too hot for too long. I held the first temp for 1 hour, definitely to long, and second temp for the 2 hours. Before I was doing the quick fire for 1 hour and it was working, I guess I will either try it again and only hold for a 1/2 hour and then continue for 1hour and 1/2.
    Or go back to a single ramp and hold?

  • Hadar Jacobson Says:

    Julie,

    When you fired before and it worked, was it in fire-brick mini kilns? I noticed, too, that in the mini kilns the carbon burns quickly, since you can’t fill them with a lot of carbon anyway. So I would say yes, in mini kilns you can fire bronze at 1460 (maybe even lower), and no for such a long time. Let me know how the second firing goes.

  • heidijo Says:

    i’ve been helping my mom program her kiln for firing your copper clay using this schedule:
    ph 1 – 1000°F/538°C (top loader brick kiln)
    ph 2 – 1470°F/800°C (top loader brick kiln)

    we held phase one for 45 minutes but didn’t cool to room temperature. (somehow missed that instruction). then ph 2 for 2 hours. everything was powder – one crumbled away when she touched.

    reran the whole cycle again, holding times longer, ph 1 = 1 hour, ph 2 = increasing temp by 15 degrees, 3 hours. again, nothing sintered properly.

    i see now that we can fire as hot as 1580 for copper only and will try the whole cycle again. is it still necessary to cool to room temperature after having been fired several times already? what does cooling to room temp do to help?

    is it unusual that the temp you list as standard for most of your clays isn’t working for us? (caldera top-loading kiln – i have the same kiln as my mom) – both are very new – less than 6 months old).

    (oh – we fired in stainless steel box with no lid. filled nearly 3/4 of the way with coconut carbon – then pieces as you show in photos – then covering with approx. 1 inch of carbon.)

    thank you hadar!

  • Hadar Jacobson Says:

    Heidi Jo,

    The steel box reduces the temperature inside the box. If you use it instead of a fiber blanket box, you need to fire higher, I am not sure by how much. It is also important where you buy tour coconut carbon. Some need a temperature that is 40F higher than my firing schedule.

    If you are firing the same pieces, you don’t need to repeat the first phase.

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