Firing temperature for earthenware

[Nelly]

Dear All,

 

I am about to crack open a new box of low fire clay. Earthenware red. I have used this before and recall that the bisque was fine at 05 but that I did not glaze fire to optimum temperature. One of my studio members said the batch I did "looks under glazed fired."

 

My question is:

 

What temperature do you bisque and glaze fire earthenware? I will be using the brush on commercial glazes for this work. I will lay down a white glaze base and decorate on top and finish with a clear glaze.

 

In my on-line research and without my notes from before, I can see there is a range of temperatures cited.

 

Does anyone use earthenware and how do you fire this clay optimally.

 

Nelly

[Guest JBaymore]

The clay and glaze manufacturer/supplier should have the exact info you need. Usually it is right on the commrcial glaze bottles.

 

Most earthenware clay and glazes are finish fired to about Orton Cone 04. The typical range (if there really is one) is Orton Cone 06 to 04. Some folks do fire hotter.............. fopr a really tight body...... maybe up to Orton Cone 2.... but most commercial glazes do not go that high. Few "low fire" commercial earthenware glazes mature below Orton Cone 07.

 

best,

 

...................john

[Marcia Selsor]

It sounds at first like you are doing majolica by using a white base glaze and decorating on top. From there I don't understand why you add the clear glaze. If you are using a white glaze and overglazing, you do not need the clear glaze. Many Majolica artists fire their bisque higher...to around ^03 or ^02 and then glaze fire at a lower temperature like ^04. Commercial overglazes can be purchased from producers like AMACO. Their "GDC" glaze decorating colors, are very popular and can go to higher temperature. No need to covering with another layer of glaze. Linda Arbuckle has generously been sharing her techniques, glazes, etc. Ceramic Arts Daily videos have a segment from her DVDs.

Her handouts will explain much of what I have mentioned above.

 

 

 

http://lindaarbuckle...handout2007.pdf

Look for more on Linda Arbuckle ceramic arts daily

 

Marcia

[Nelly]

The clay and glaze manufacturer/supplier should have the exact info you need. Usually it is right on the commrcial glaze bottles.

 

Most earthenware clay and glazes are finish fired to about Orton Cone 04. The typical range (if there really is one) is Orton Cone 06 to 04. Some folks do fire hotter.............. fopr a really tight body...... maybe up to Orton Cone 2.... but most commercial glazes do not go that high. Few "low fire" commercial earthenware glazes mature below Orton Cone 07.

 

best,

 

...................john

 

 

Dear John,

 

As I recall, there was a lot of back and forth about this in the studio the last time I did it. So your suggestion is 04 bisque and then whatever it says on the bottle for the glaze temperature range. And yes, colors do burn out the the higher you go. I do this. So I will look and see what colors I hope to use.

 

So, I think what you are saying is that the bisque firing is 04 and the glaze is whatever range is presented on the bottle.

 

I will check this on the labels.

 

When I called my clay supplier about this the last time, they were a little unsure as they didn't sell that much of this brand. So I think I probably did it to 04 in the community studio at the time.

 

Thank you for your help.

 

Nelly

[TJR]

Nelly;

I use a Terra Cotta clay from Plainsman. Tuckers probably also supplies a good red earthenware. I bisque at cone07-06. I glaze fire at cone 04 for majolica.

I have read that Linda Arbucle article. She lists one glaze recipe at cone 03 and one at cone 05.If you are using commercial glazes in a jar, they usually fire at cone06. Should be right on the label.

TJR.