Firing Two Phases in One Uninterrupted Session

Yes, this means you can start firing before you go to bed at night, and in the morning the second phase will be over.

This not only makes the firing process simpler; it also makes 2-day workshops feasible.

Why didn’t I think of this before? I don’t know. Why didn’t kiln manufacturers tell us that? I only thought of it because I got an email from a customer whose workshop is far from her house and it’s a hassle for her to go there a second time to start the second phase. So thank you for asking me this question – you know who you are!

In this PDF file you will find instructions for programing the kiln to fire 2 phases in one firing session. The instructions are both for the Sentry Xpress controller and for the Bartlett controller. Choose the instructions that apply to your controller.

Here is a short explanation:

You program the kiln to fire the first phase.
After doing this, the kiln will ask “rA2”, which means “At what speed would you like me to ramp the second time around?” Usually we say 0:00, which makes the kiln stop asking questions and start firing.
This time we say “Full,” and the kiln will keep asking questions. Next question is “At what temperature would you like me to fire the second time around?” Say 100ºF/50ºC.

The kiln will then ask: “How long would you like me to hold the second time around?” Say 0:00. No hold.
What we just did is tell the kiln to cool to 100ºF/50ºC.

The kiln will then ask: “At what speed would you like me to ramp the third time around?” We say Full or 1400ºF, depending on the kiln.
The kiln will ask: “At what temperature would you like me to fire the third time around?” We tell it our temperature for mid-fire schedule.

We just told the kiln to start phase 2 after it has reached 100ºF/50ºC. You entered 3 consecutive programs.

It will ask you: “At what speed would you like me to ramp the fourth time around?” Now you say 0:00 to shut it up.

Bartlett controllers work a little differently. They ask you at the outset how many programs you want to enter by the question “SEG” (number of segments). You tell it 3, and it won’t ask you for the fourth time around.

We can’t make the kiln cool faster than it would naturally do; we can only make it cool slower (which is important in the case of glass), but this is not what we want. If you are not firing overnight, you can open the kiln to cool it faster. Just don’t forget to close it when it starts phase 2.


16 Responses to “Firing Two Phases in One Uninterrupted Session”

  • Leslie Scott Says:

    One of those “brilliant ta dahhh” moments!! Thanks Hadar!

  • Julie Cannariato/ ArtZcat Creations Says:

    Thanks Hadar! I have actually done this in the past in my SC2 and experienced that it took a long time for the kiln to cool to 100 degrees. You say it is OK to help speed the cooling between phase one and two? I had always left the door closed thinking that perhaps it needed to cool slowly after phase one for complete burning off of the binder. I am thinking now that maybe it is just to have a consistant “pre-heat” period starting from room temp in phase 2. Could you please elaborate and explain why we wait for the kiln to come to room temp after phase 1?

    Thansk for all you do!

  • Melody Pierson Says:

    Will these instructions work on my Paragon Digital Firefly?

  • Rolf Friberg Says:

    I have done this but if you want to do it over night you have to go up and pour carbon over the items before phase two starts. That is if you fire the first phase with the items just laying on the carbon bed but not covered.
    And as i have followed the old rule not to have the items covered during the first phase I had to start the first phase early as I don’t want to stay up after midnight. As I have understood it , you cannot fire all combinations covered by carbon from start, including the first phase. As everything has to dry before we can start the first phase, we have not been able to have a class two days in a row.

  • Kris Says:

    thank you for sharing your ah ha moment.

  • Hadar Jacobson Says:

    Julie, It’s ok to fast-cool after phase 1. No need for slow cooling.

  • Hadar Jacobson Says:

    Rolf, As described in the latest version of the instruction manual, the pieces are covered with carbon at both phases.

  • Janice Wiggins Says:

    Awesome Hadar! I never payed attention to the r2 either. I can’t wait to try this!

    Janice Wiggins
    JMW Silver

  • Linda Reboh Says:

    Thanks so much! This will make teaching spool much easier!

  • Freda Says:

    I think I am confused. Do you burn the binder off 1st and then do 2 firings? Or do you bury the material in carbon to burn off the binder?

  • Hadar Jacobson Says:

    Freda, The binder is burnt at the first phase while the pieces are covered with carbon.

  • Sylvia Says:

    Hadar,

    1. I will be attempting two phase firing on copper. “Full” ramp on my muffle kiln is 1800 degrees. Do I choose “Full” or “1400”?

    2. You say to cool to 100degrees…but in your instruction manual, you say 450. Which is best?

    3. For copper you say fire at 1780 degrees but for best strength 1830…”but with 2 phase firing”. Does this mean “except with 2 phase firing” or “only with 2 phase firing.”

    Sorry for all the questions.

    Sylvia

  • Hadar Jacobson Says:

    Sylvia,
    1. 1400F
    2. 450F is fine.
    3. Copper always needs 2 phase firing. It will be stronger and shrink more at 1830, but will be perfectly fine at 1780 and even less.
    I hope it helps!

  • Carla Says:

    Hadar, I tried the combination of the two phases in one. It failed. I made a tube bead from low shrinkage steel XT and sealed the seam with thick steel paste. The end caps were quick fire copper with holes for stringing. I filled the bead half way with carbon, stood it up vertically in the carbon, and followed the combination firing schedule. I have a kingpin 88 kiln with a bartlett controller. I was hesitant about the 1510 degree temp in the instruction since copper usually fires much higher. The result was that the copper crumbled apart and the seam opened on the steel bead. So I am wondering, is the target temp really that low? Any suggestions?

  • Hadar Jacobson Says:

    Carla, Yes, the temperature was too low. Combination of copper and bronze requires 1750F in a brick kiln or 1830F in a muffle kiln.

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