[Marilyn Stew]

I have a very small keln. My ceramic art instructor told me that all ceramics needed to be high fired to make them more durable. I like low fire commercial glazes because of all the color options and the predictability of the glazes as opposed to self mixed glazes. However, my kiln is a small low fire one. I use porcelain clay to do sculptures. If I bisque fire my sculptures then low fire glaze them will they be structurally sound and have adequate permanency? Or, do I need to do a second high fire using self mixed glazes? Is it really necessary to high fire ceramics or are there low fire methods that result in the same structural permanency?

Thank You and have a good day!

[hansen]

Marilyn: Try it - it might be good. Often in raku work cone 6 clay is used but firings reach cone 05 at the highest. You can't make pots or dishes that go through the dishwasher this way but sculptural work, why not?
h a n s e n

[Marilyn Stew]

hansen, on 20 June 2010 - 10:18 AM, said:

Marilyn: Try it - it might be good. Often in raku work cone 6 clay is used but firings reach cone 05 at the highest. You can't make pots or dishes that go through the dishwasher this way but sculptural work, why not?
h a n s e n

Thank you. I've done racu. It was one of the class projects when I took a ceramics class this last semester. And you are right, its not like the sculptures are going to be put in the dishwasher. They just need to be stable enough to wipe with a damp cloth and handled.

[Lucy]

Marilyn: you might want to try a low fire earthenware sculpture clay. It's made for that temperature and most people find it far easier to sculpt with than porcelain. Then you know the clay is maturing at that temp. and it's a good fit for low fire commercial glazes, too.

[Marilyn Stew]

Lucy, on 20 June 2010 - 03:32 PM, said:

Marilyn: you might want to try a low fire earthenware sculpture clay. It's made for that temperature and most people find it far easier to sculpt with than porcelain. Then you know the clay is maturing at that temp. and it's a good fit for low fire commercial glazes, too.

Thank You Lucy, my professor mentioned that there was a low fire clay but for some reason he wanted me to try porcelain, perhaps because of the color factor or perhaps because he had extra and just wanted some sap like me to buy it and get it out of inventory. My sculptures are detailed and small yet heavy because I have not yet learned good methods for carving out the inside. I am finding it impossible with porcelain to make anything of very big size because everything collapses in on itself. I am tenaciously trying to create with the porcelain I have left though. My husband is going to make me a roller so that I can hand build some functional pieces. I enjoy creating both non utilitarian sculptual forms as well as functional forms. But I seem to have more of a nack for taking my drawings and putting them in sculptural form.

[Teresita]

Yes, Marylin, I agree with Lucy. Porcelain is not an easy clay to work with in the manner you are using it for. For Sculpture you do not have to worry about hi or lo fired as long as it is for indoors and no freezing and thawing to deal with. There is no "right or wrong" way to be an artist, you just need to understand the qualities of the materials you're working with and allow yourself the permission to experiment.
have fun and good luck!

[Marcia Selsor]

Marilyn Stew, on 19 June 2010 - 03:23 PM, said:

I have a very small keln. My ceramic art instructor told me that all ceramics needed to be high fired to make them more durable. I like low fire commercial glazes because of all the color options and the predictability of the glazes as opposed to self mixed glazes. However, my kiln is a small low fire one. I use porcelain clay to do sculptures. If I bisque fire my sculptures then low fire glaze them will they be structurally sound and have adequate permanency? Or, do I need to do a second high fire using self mixed glazes? Is it really necessary to high fire ceramics or are there low fire methods that result in the same structural permanency?

Thank You and have a good day!

In a later post you say you are working with porcelain. You could make paper clay from the porcelain scrap by soaking it, adding paper pulp, and drying it to a workable consistency. This will help with the hand building with porcelain problems you are having. Also, when firing paper clay, you should fire a cone higher than you would without the paper pulp.
As for making your low fire clay strong, you need to fire it to the point of maturity. Contact the manuacturer to find out what that is. If you are mixing your own clay, do absorption tests. Google for directions.