Christina Piccuta on mon 8 aug 05
I have access to a kiln for the first time but I will be totally on my own
and I don't know what to do. I have taken pottery courses but the teacher
has always done the firing. What I would like to do to start is to paint
some pre-made bisque tiles and fire them. Can I fire at cone 6 or 8 or does
it depend on the glaze? Also, how long to I fire? Does a kiln need to be
filled in order to do a firing or can I do a test fire? I know these are
very basic questions but I don't want to just throw a couple of tiles in
the kiln at the wrong temperature and for the wrong length of time and have
something bad happen. Any advice will be hugely appreciated.
Christina
William & Susan Schran User on mon 8 aug 05
On 8/8/05 5:27 AM, "Christina Piccuta" wrote:
> What I would like to do to start is to paint
> some pre-made bisque tiles and fire them. Can I fire at cone 6 or 8 or does
> it depend on the glaze? Also, how long to I fire?
What do you know about the tiles you want to glaze and fire? You need to
find out what temperature they can be fired to - cone 06 or cone 6 - it does
make a big difference.
The firing temperature will depend on the clay the tiles are composed of and
the firing temperature of the glaze you apply, and they should both be the
same.
Do you have a manual for the kiln? The manual will give you firing
directions. If you don't have one, contact the kiln manufacturer and get one
before you try to fire the kiln.
--
William "Bill" Schran
Fredericksburg, Virginia
Snail Scott on mon 8 aug 05
At 05:27 AM 8/8/2005 -0400, you wrote:
>...Can I fire at cone 6 or 8 or does
>it depend on the glaze?
It needs to be a glaze that was made for your intended=20
temperature. If you want to fire to ^6, it needs to=20
be a ^6 glaze. It also needs to be ^6 clay. Some bisqued=20
commercial tiles are low-fire (i.e. ^04 or so), so make=20
sure you get the right kind.=20
>...Also, how long to I fire? Does a kiln need to be
>filled in order to do a firing or can I do a test fire?
If it's a manual kiln (no computerized controller), you=20
will need witness cones to judge the temperature. If=20
you are shooting for ^6, put in ^5, ^6, and ^7, in front=20
of a peephole where you can keep an eye on them. When=20
the ^5 bends, get ready. When the ^6 bends, turn it off.=20
If the ^7 bends, it's basically telling you that you=20
overshot the mark, but just a little. For tiles, spend
several hours 'candling', i.e. running on 'low' with=20
the lid propped open to drive off the last of the=20
moisture.Then an hour on 'low' with the lid shut, an=20
hour on medium, and then turn it to 'high' and wait for=20
the cones to bend.Depending on the kiln, that will take=20
5-8 hours, or more. Every kiln is different.=20
If it has a kiln-sitter, put an appropriate numbered=20
cone in the sitter. (These are a different type of cone=20
than the witness cones!) Use witness cones, too, though,=20
so you can see if the sitter was calibrated 'true'.
If it's a computerized kiln, you'll need to know how to=20
do the program entry, but the principle remains similar.
Several hours of keeping the temperature below 200=BAF,=20
with the lid propped slightly open,then a rise of about=20
150=BAF per hour til you reach ^6.
It'll take however long it takes. Just wait for the=20
cones to bend (or for the controller to turn off.)=20
Start very early in the day so that you can be there=20
'til it's done. It's OK to go for lunch or coffee, but=20
be around to keep an eye on it, especially toward the=20
beginning and end, since it's your first time using=20
that kiln.
The kiln won't need to be full, and it will fire a bit=20
faster if it's not. A full kiln is a less wasteful use=20
of power, but a load of messed-up work is even more=20
wasteful, so doing a test firing of just a few pieces=20
is a good idea.
PLEASE, before you begin, get someone with experience=20
to check out what you're doing. There are lots of=20
little things that I just won't try to describe in an=20
e-mail, like how to make a cone pack, or the right way=20
to prop a lid. A five-minute hands-on demonstration by=20
someone standing next to you will be worth 100 e-mails=20
on the subject.
Read a basic text on the subject, too. It'll help a=20
lot, and there are many good books out there. Your=20
local library is bound to have several.
-Snail=20
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