New At Kiln Firing, Please Help! *_*

[MeliNC]

 

Hi everyone!; I recently bought an automatic kiln (a Cress E23) and last weekend it was installed; it is ready to go, so naturally I am itching to do a test firing to see it in action.... however I have always had my pieces fired at a community studio, and although I have spent countless nights of online research, I am stuck on the firing schedules... I don't know what cone to fire for the bisque, and for the high firing, I don't know if I should add any special timing/soaking to the preset firing schedule for cone 6.

 

My kiln is automatic, so it does have preset ^ firings, however I work strictly with porcelain and I am having doubts on:

 

1. Bisque firing -- what cone do I fire it at??

2. High Firing -- Do I hold?, is there any tips/secrets I should know to make the most of my firing and help my porcelain survive?

 

 

I use Highwater Helios porcelain clay .

 

 

I appreciate any suggestions and advice!

 

 

Thanks!

 

Melissa

[neilestrick]

First, Helios is a cone 10 porcelain, so at cone 6 you shouldn't have any problems with slumping. You should switch to a cone 6 porcelain to help with glaze fit, and to get your clay to fully mature.

 

I bisque to cone 04, glaze fire to cone 6. No hold unless glaze problems arise. Just use the pre-programmed firings in your controller. No need for a custom firing schedule at this point.

[MeliNC]

First, Helios is a cone 10 porcelain, so at cone 6 you shouldn't have any problems with slumping. You should switch to a cone 6 porcelain to help with glaze fit, and to get your clay to fully mature.

 

I bisque to cone 04, glaze fire to cone 6. No hold unless glaze problems arise. Just use the pre-programmed firings in your controller. No need for a custom firing schedule at this point.

 

 

Hi Neil, good to see you again (my new kiln is the one you had previously advised me on checking properly when I was buying it about 3 months ago!).

 

 

I am kinda using the firing cone temps that the community studio I use; they bisque at 04 and glaze at 5; I did notice that highwater clay rates helios for 7-11...I don't know if the studio just uses a simple range firing schedule since they fire over 6 different clay bodies all at the same time.

 

I have experienced deformed bowls and cracked rims (I handbuild only). I noticed that with 1/4 inch + slabs, the pieces have turned out much nicer and much more reliable.., however the cracks still appear ever so often.

 

When you say "glaze fit", do you mean matching glaze cone to clay cone? ex. cone 6 porcelain + cone 6 glazes?...

 

 

Thanks for the help!...I am getting so much information overload that I think I may be overthinking things, but I rather be informed than not.

 

 

Melissa

[neilestrick]

Glaze fit refers to how well the glaze fits with the clay body. Often, cone 5/6 glazes will craze on cone 10 clay bodies. Even if they're firing many different clay bodies, if they are only ever glazing at cone 6, they should be using cone 6 clay bodies to ensure getting fully matured, strong pots. I have 5 different clay bodies in my studio, all cone 6.

 

Porcelain can be very difficult to handbuild with. If I were you I'd try a white stoneware. It will have more plasticity and less shrinkage, and may fix many of the cracking and warping problems you are having.