Clay recipes
PORCELAIN CLAY RECIPES AND OTHER INFORMATION ABOUT THE MAKING OF PORCELAIN CLAY.
There are countries where porcelain clay is not available and in some countries, it is difficult to get porcelain clay. For that reason and for the sake of my students and anyone interested in porcelain, I would like to use this page to share my experiences with porcelain clay. I will share experiences with known porcelain clay bodies and I will also share possible recipes with you. If you have any experiences that you would like to share with me, I will appreciate that. Contact me and let's share ideas.
Understanding Porcelain online workshopClick on the link above to go to my porcelain online workshops.
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How to mix porcelain from a recipeQuality Control
Keep rusted metal out of your clay. It is critical that porcelain stays pure, or else you can just as well work with stoneware clay. Keep the water that is used pure and iron free as possible. Use the purest raw materials you can get; that is the ones with the least iron and organic matter. There is no real shortcut for developing clay bodies. Hand mix a series chosen tests so that you can learn about the properties of the various raw materials you have available. |
Translucency
Less clay in the porcelain cause shortness, but will enhance translucency.
Whiteness
The whiter the clay is, the brighter the glazes, but there should be a fine balance between whiteness, translucency (which happens in the absence or limitation of opacifying materials in the kaolin and or ball clay).
Range and Glaze Fit
The silica/feldspar balance will help for a good glaze fit. Too much silica will cause dunting of the clay body and too little will cause crazing of the glaze.
Feldspar Choices
Choose sodium feldspar for its longer firing range or potash for a higher firing. Lower firing feldspar like Nepheline Syenite, has a good melting, but is not only expensive, but it also causes troublesome, thixotropic clay as the soluble materials becomes like gel, causing hard unworkable clay that must be softened before using. I will not use it.
Custer Feldspar, Minspar 200 or Mahavir feldspar can be used. Minspar is the main Soda Feldspar on the market now. Ignore the G200 as it is discontinued. Custer and Mahavir will probably melt at ^8-10 while Minispar will start melting at ^6-9.
Kaolin
Grolleg (china clay) is the best one to use, but not very plastic. The one from England (Super Standard China Clay) is less plastic, but whiter and more translucent.
Tile 6 is very plastic, but not very translucent.
C+C is ball clay that contain kaolin. It may be a bit more plastic, but it can add too much silica to the clay, and will opacity the clay.
How to mix
Mix small batches of porcelain clay to test the shrinkage and performance. Mix old, clear clay water with the powder into a thick slip. Old clay water that separated from the clay and is clear, will have good bacteria that will help the aging process.
Let the slip rest overnight (24-36 hours) and place it then on an absorbing surface where it dries out until it can be wedged. Let it sit for a few days. Note the clay will still be fresh, but it is possible to test it for future possibilities.
Do the following:
Make a knot test to test for workability.
Make test tiles of 10 inches or 10 centimeters long. Fire and test for shrinkage, vitrification.
For good performance let it sit for at least 3 months.
Less clay in the porcelain cause shortness, but will enhance translucency.
Whiteness
The whiter the clay is, the brighter the glazes, but there should be a fine balance between whiteness, translucency (which happens in the absence or limitation of opacifying materials in the kaolin and or ball clay).
Range and Glaze Fit
The silica/feldspar balance will help for a good glaze fit. Too much silica will cause dunting of the clay body and too little will cause crazing of the glaze.
Feldspar Choices
Choose sodium feldspar for its longer firing range or potash for a higher firing. Lower firing feldspar like Nepheline Syenite, has a good melting, but is not only expensive, but it also causes troublesome, thixotropic clay as the soluble materials becomes like gel, causing hard unworkable clay that must be softened before using. I will not use it.
Custer Feldspar, Minspar 200 or Mahavir feldspar can be used. Minspar is the main Soda Feldspar on the market now. Ignore the G200 as it is discontinued. Custer and Mahavir will probably melt at ^8-10 while Minispar will start melting at ^6-9.
Kaolin
Grolleg (china clay) is the best one to use, but not very plastic. The one from England (Super Standard China Clay) is less plastic, but whiter and more translucent.
Tile 6 is very plastic, but not very translucent.
C+C is ball clay that contain kaolin. It may be a bit more plastic, but it can add too much silica to the clay, and will opacity the clay.
How to mix
Mix small batches of porcelain clay to test the shrinkage and performance. Mix old, clear clay water with the powder into a thick slip. Old clay water that separated from the clay and is clear, will have good bacteria that will help the aging process.
Let the slip rest overnight (24-36 hours) and place it then on an absorbing surface where it dries out until it can be wedged. Let it sit for a few days. Note the clay will still be fresh, but it is possible to test it for future possibilities.
Do the following:
Make a knot test to test for workability.
Make test tiles of 10 inches or 10 centimeters long. Fire and test for shrinkage, vitrification.
For good performance let it sit for at least 3 months.
Note
The recipes shared worked for her at the time when she tested and mixed them and used them on her selected clay bodies. Raw materials constantly change due to the location where it is mined. Therefore, always test these recipes for your personal circumstances. Antoinette does not take responsibility for any errors in any of the glazes that you mix and used from this page.
The recipes shared worked for her at the time when she tested and mixed them and used them on her selected clay bodies. Raw materials constantly change due to the location where it is mined. Therefore, always test these recipes for your personal circumstances. Antoinette does not take responsibility for any errors in any of the glazes that you mix and used from this page.
Grolleg Porcelain Recipe.
(I used this one for ^10 as well as for pit fired work)
EPK 28 kg China clay - 28 kg Silica(# 200) - 18 kg Potash feldspar - 15 kg Bentonite - 1 kg * NOTE: This is not a translucent porcelain clay body, but a reliable plastic body that worked well with several glazes. I will have to re test it to get the shrinkage and the level of absorbency. |
Ceramics Monthly published several ^6 translucent porcelain recipes that Antoinette tested in their December 2016 Magazine
"There is a constant striving by ceramic artists to improve the workability, color and stability of porcelain clay bodies.........." |
Porcelain clay recipes from other sources
Non-translucent ^9-10 ( Not tested by Antoinette)
Recipe 1
Grolleg 55
Custer 18
Flint 16
EPK 9
Pyrophyllite 2
Bentonite 2
Molochite, 200 mesh or finer, 3
Recipe 2
Grolleg 40
Custer 34
Flint 26
Macaloid 4
Recipe 3
Cone 8-12
Porcelain body
Ball clay 27
Kaolin 27
Potash 27
Flint 19
Recipe 4
Ball clay 27
Kaolin 27
Potash 27
Flint 19
*NOTES*
Some of these recipes contains ball clay. Pure porcelain consists of the 3 main ingredients namely Kaolin, Silica and Feldspar. Anytime when different materials are added, there is a move away from pure porcelain. Antoinette delivers the information of available recipes, but does not take responsibility for the outcome
Recipe 1
Grolleg 55
Custer 18
Flint 16
EPK 9
Pyrophyllite 2
Bentonite 2
Molochite, 200 mesh or finer, 3
Recipe 2
Grolleg 40
Custer 34
Flint 26
Macaloid 4
Recipe 3
Cone 8-12
Porcelain body
Ball clay 27
Kaolin 27
Potash 27
Flint 19
Recipe 4
Ball clay 27
Kaolin 27
Potash 27
Flint 19
*NOTES*
Some of these recipes contains ball clay. Pure porcelain consists of the 3 main ingredients namely Kaolin, Silica and Feldspar. Anytime when different materials are added, there is a move away from pure porcelain. Antoinette delivers the information of available recipes, but does not take responsibility for the outcome
Cone 6 porcelain recipes ( Not tested by Antoinette)
Grayish porcelain for throwing non- translucent)
Georgia kaolin 40
Potash 25
Ball clay 10
Tenn #1 ball clay 6.5
Silica 13.5
EPK 5
Bentonite 2
Campana porcelain Cone 5-8 ( non- translucent)
Grolleg Kaolin 25
C&C Ball Clay 10
Tile #6 Kaolin 10
Minspar 200 35
Silica 325# 20
Bentonite L-10 White 2.5
Ron Roy recipe
EPK 25
Ball clay25
Minspar 25
Silica 25
Bentonite 1-2 %
Grayish porcelain for throwing non- translucent)
Georgia kaolin 40
Potash 25
Ball clay 10
Tenn #1 ball clay 6.5
Silica 13.5
EPK 5
Bentonite 2
Campana porcelain Cone 5-8 ( non- translucent)
Grolleg Kaolin 25
C&C Ball Clay 10
Tile #6 Kaolin 10
Minspar 200 35
Silica 325# 20
Bentonite L-10 White 2.5
Ron Roy recipe
EPK 25
Ball clay25
Minspar 25
Silica 25
Bentonite 1-2 %
^ 6 recipes developed by Antoinette
Recipe 1 (grayish, but somewhat translucent, plastic)
EPK Kaolin 25
Silica 25
Minspar 25
Custer 25
Macaloid 2
Recipe 2 ( grolleg white, plastic, translucent)
China Clay 25
Silica 25
Minispar 25
Custer 25
Macaloid 3
Recipe 1 (grayish, but somewhat translucent, plastic)
EPK Kaolin 25
Silica 25
Minspar 25
Custer 25
Macaloid 2
Recipe 2 ( grolleg white, plastic, translucent)
China Clay 25
Silica 25
Minispar 25
Custer 25
Macaloid 3
*Disclaimer* These recipes are developed and tested in my studio, under my personal care. I recommend that anyone that wants to use these recipes, test it first. I do not take responsibility for other potters and what they do with the information provided on this page.
Bone china recipes ( Not tested by Antoinette)
Bone china is a type of porcelain that developed around the 1800's in England, while the fever after porcelain white gold were high. It developed from a search to improve soft paste porcelain. When the value of calcined cattle bones in the clay body were discovered, a new era in porcelain began. Josiah Spode was the potter that perfected the medium in England.
It is a very tight medium that is traditionally slip cast.
The traditional recipe for bone china is as follows:
50% bone ash
25% Feldspar
5% Kaolin
Other potters developed recipes with more kaolin to try to control the workability.
Bone China Casting Recipe
(cone 6)
Ecalite Kaolin 30
Bone ash 45
Potash Feldspar 23
Silica 200 mesh 2
Dispex 3
Throwing Bone China Body
(cone 5-6)
China clay 55
Potash feldspar 25
Silica 15
Bentonite 5
Bone ash 10
*NOTE*
I have not tested these recipes, therefor I suggest you test before you mix large batches. If you do, please let me know about your results.
It is a very tight medium that is traditionally slip cast.
The traditional recipe for bone china is as follows:
50% bone ash
25% Feldspar
5% Kaolin
Other potters developed recipes with more kaolin to try to control the workability.
Bone China Casting Recipe
(cone 6)
Ecalite Kaolin 30
Bone ash 45
Potash Feldspar 23
Silica 200 mesh 2
Dispex 3
Throwing Bone China Body
(cone 5-6)
China clay 55
Potash feldspar 25
Silica 15
Bentonite 5
Bone ash 10
*NOTE*
I have not tested these recipes, therefor I suggest you test before you mix large batches. If you do, please let me know about your results.
Parian ware
Prior to parian ware (which is a self glazing porcelain clay body) biscuit porcelain was used to imitate marble statues. I will soon post more information and recipes about parian ware.
See the article here: Composing a Workable Parian Clay Body