search  current discussion  categories  kilns & firing - misc

## bisque and glaze fire

### Alisa Reinstein on sat 2 oct 04

Hi,
I just got a new L&L kiln. I'm running the "maiden" fire right now. It's
scheduled to take 17-19 hours. But I'm trying to figure out how long a
typical bisque and a typical glaze (cone 5) will take, so I'll know when
to start it so I can be around for the end. Any ideas?
Thanks,
Ali

### Ivor and Olive Lewis on sun 3 oct 04

Dear Alisa Reinstein,
Given that a bisque will run to Cone 08 and firing rates given for
Orton Cones are 60=BA C and 150=BA C you have a choice of a slow firing,
say for thick or large pots and a fast firing for thin small pots. For
the former heating rate the finishing temperature is given as 945=BA so
the estimated time will be 15 hrs 45 mins. For the latter heating rate
of 150=BA C/hr your firing should be completed soon after 6 Hrs 20 mins
have elapsed.
At Cone 5 and 60=BA C/hr expect 19 hrs 40 mins. At 150=BA/hr expect 8 hr=
s
I suggest you find a copy of Hamer's Potter's Dictionary of Materials
and Techniques. It is a text that contains information that would
enable you to make these calculations for yourself.
I hope you have great success with your new kiln and look forward to
seeing examples of your work in Chris's special site.
Best regards,
Ivor Lewis.
Redhill,
S. Australia.

----- Original Message -----
From: "Alisa Reinstein"
To:
Sent: Sunday, 3 October 2004 12:13
Subject: bisque and glaze fire

> Hi,
> I just got a new L&L kiln. I'm running the "maiden" fire right now.
It's
> scheduled to take 17-19 hours. But I'm trying to figure out how
long a
> typical bisque and a typical glaze (cone 5) will take, so I'll know
when
> to start it so I can be around for the end. Any ideas?
> Thanks,
> Ali
>
>
______________________________________________________________________
________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your
subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at

### Gene and Dolita Dohrman on sun 3 oct 04

Your new L&L should have come with a binder full of information of exactly
that nature. They describe their firing schedules very clearly. My typical
bisque is the slow bisque program and takes about 11.5 to 12 hours.
However, every kiln is different. Have yet to do my first glaze firing but
it is going to happen very soon. My tests are in and they are looking good!
Dolita

dohrman@insightbb.com
Louisville, KY

> Hi,
> I just got a new L&L kiln. I'm running the "maiden" fire right now. It's
> scheduled to take 17-19 hours. But I'm trying to figure out how long a
> typical bisque and a typical glaze (cone 5) will take, so I'll know when
> to start it so I can be around for the end. Any ideas?
> Thanks,
> Ali
>
>

### william schran on sun 3 oct 04

Alisa wrote - > But I'm trying to figure out how long a
typical bisque and a typical glaze (cone 5) will take, so I'll know when
to start it so I can be around for the end. Any ideas?<

Congratulations on your new L&L kiln. I'm sure you'll be pleased with it.

There are far too many variables for anybody to tell you how long any
particular firing will take.

You write: "...so I can be around for the end." Where are you going?
I hope you're not planning to go off and leave the kiln. That's the
first big no no in firing any kiln!

You didn't write whether this kiln has a programmable controller or
not, but let's assume it does. The controller will be getting it's
information from thermocouples. These will degrade over time, so the
reading of the controller will change over time. Now's a good time to
get into the habit of using witness cones which will provide you with
the most accurate reading of the firing, bisque or glaze.

Bill

### Alisa Liskin Clausen on sun 3 oct 04

On Sat, 2 Oct 2004 22:43:16 -0400, Alisa Reinstein
wrote:

>Hi,
>I just got a new L&L kiln. I'm running the "maiden" fire right now. It's
>scheduled to take 17-19 hours. But I'm trying to figure out how long a
>typical bisque and a typical glaze (cone 5) will take, so I'll know when
>to start it so I can be around for the end. Any ideas?
>Thanks,
>Ali

Dear Ali,
Contratulations on your new kiln. It is always a good idea, like you are
planning, to be there for the scheduled shut off time, to be sure the kiln
shuts off. It is also good idea to have access to the kiln while firing,
to be sure it firing on schedule. If there is a fault, you can be there to
stop the kiln, instead of it hanging up at a high temperature or the
temperature raising too rapidly, etc.

Typically, a bisque firing takes between 8-10 hours and an electric glaze
firing has many more variables, depending on the glazes you are using f.ex.
gloss, mats or crystals.

If you have John and Ron's book, Mastering Cone 6 glazes, they recommend a
slow cool down. This adds hours to the firing, but on the way down. A
slow cooling is important to give the mat glazes time to create small
chains of crystals to give the mat surface. Cool down rates will also
depend on your glazes. Mastering Cone 6 glazes recommended cool down was a
little too long for my glazes, so I altered it to acheive good mats,
without overfiring the glazes. With gloss glazes, I fire to top
temperature, and hold only 5 minutes and shut off.

If we are only talking about the time to reach cone 5, a typical ramp may
be 100c p/h to 400c, 150c p/h to 1100c, and 80c p/h to 1215c. You can
convert this f. easlily with a chart. On the way down with mats, I hold at
the top for 5 minutes, cool down naturally to 800c, hold for one hour and
shut off the kiln.

That would take the kiln 10 hours to fire to top temp.
Then you would add the soak periods, hoid and cool down ramps. Could add
another 6 hours.

I almost always candle my bisques over night at 200c. I The next day I
fire a slow bisque, but not extra slow if I was not sure that all of my
work was bone dry from the candling, or if I was firing something very
large and/or thick.

Bisque goes 100c p/h to 400c. 150c to 1000c and off.
That is 8 hours. If I had not candled, I would raise the temperature to
200c, hold 1 hour, hold again for one hour at 300c and then fire up to
1000c.

This is what I use and could be a guideline for you. In general you want a
slow bisque. Glaze firings need time allowed to let the glaze heal over at
the top temperature with a hold, and as said, a slow cool down is often
important to achieve mat surfaces. Then you will probably find some
finnicky glazes, that need a program all to themselves. I have never loved
one glaze so much that I could afford it so much indulgence as private
firings. But you may, or it could happen to me sometime.

before you need to replace the elements. But that is a long time from now.

Good luck with you new kiln.

regards from Alisa, name partner in Denmark

>
>___________________________________________________________________________
___
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at

### Christy Pines on sun 3 oct 04

I haven't done any glaze fires yet in my new L&L e23s but I've done lots of slow bisque. Using the slow bisque setting is to cone 06 is usually 12 hours. If you add some preheat at the beginning, as I usually do, it increases the time. Yesterday, the kiln reached temp and turned off after 16.6 hours. That included the 4 hours preheat to get those lids to dry.

christy in connecticut, getting ready for raku rhody-o and then going to have to dive into glazing. Yikes!
cpines at ix.netcom.com
member, Potters Council

-----Original Message-----
Alisa Reinstein wrote:

But I'm trying to figure out how long a
typical bisque and a typical glaze (cone 5) will take, so I'll know when
to start it so I can be around for the end. Any ideas?
Thanks,
Ali

______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org

You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/

Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.

### John Rodgers on sun 3 oct 04

Alisa,

I have a big, new Paragon TnF kiln. Glaze firing is taking 11-12 hours
for a full load fired to cone 5. The kiln runs about 8 hours for bisque
when fully loaded. In any case, it works out to a 24 hour turn-around
from start up to cool-down sufficiently to unload.

Regards,

John Rodgers
Chelsea, AL

Alisa Reinstein wrote:

>Hi,
>I just got a new L&L kiln. I'm running the "maiden" fire right now. It's
>scheduled to take 17-19 hours. But I'm trying to figure out how long a
>typical bisque and a typical glaze (cone 5) will take, so I'll know when
>to start it so I can be around for the end. Any ideas?
>Thanks,
>Ali
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>

### Neal on sun 3 oct 04

Ali: I've fired my new L&L four times. The times given in
the instruction manual have been pretty close. I've been
starting with a preheat period in my firings, so the kiln
isn't cold when the program kicks in. So far, I've done two
slow bisque firings to cone 06 that have taken about 13
hours and two slow glaze firings to cone 6 that have taken

The pages in my manual are in appendix F of the Control
section, which is this PDF:

http://www.hotkilns.com/dynatrol-instruct-blue.pdf

The manual says that the times given are for firing an
empty kiln and that a fully loaded kiln will take up to
four times longer. My firings have not been packed full but
the shelves I have have been fairly full. I could
definitely squeeze in a few more small pieces but not any
more large ones.

Neal
neal126@yahoo.com

__________________________________
Do you Yahoo!?
New and Improved Yahoo! Mail - 100MB free storage!
http://promotions.yahoo.com/new_mail

### Hal Giddens on mon 4 oct 04

I have a Skutt KS-1018 electric kiln which does not include the computer
controller. I have 2 switches and both have a low, medium and high
settings. For both bisque and glaze firings I start out with both switches
set on low for two hours and then change to medium for two more hours and
then go to high. I always do a presoak for the bisque firing for anywhere
from 8 to 12 hours to make sure the the pots are good and dry. The bisque
(cone ^04) firings are currently taking 7 hours and the glaze (Cone ^6)
firing 9 hours. I currently do not use any special cool down method but am
planning on testing that later in the year. I'm currently working on
getting pots made for two big shows in November so I'm concentrating on
that for now.

Hal Giddens
Home Grown Pottery
Rockledge, Ga.

### Arnold Howard on tue 5 oct 04

If your kiln is digital, you can figure firing time mathematically. You will
need the firing schedule to do this.

For each segment, subtract starting temperature from target temperature.
Then divide by rate per hour. This will give you the minutes/hours per
segment. Add any holds and preheat. If the kiln can't keep up with the
schedule due to worn elements or a heavy load, the firing will take longer.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
arnoldhoward@att.net / www.paragonweb.com

> Alisa Reinstein wrote:
> >Hi,
> >I just got a new L&L kiln. I'm running the "maiden" fire right now.
It's
> >scheduled to take 17-19 hours. But I'm trying to figure out how long a
> >typical bisque and a typical glaze (cone 5) will take, so I'll know when
> >to start it so I can be around for the end. Any ideas?
> >Thanks,
> >Ali