Thursday, April 10, 2014

Egyptian faience (Egyptian paste) recipe



I've had some requests for the Egyptian faience (Egyptian paste) recipe I was using in the Clay Club demo last month. Here it is, from Issue 35 of Ceramics Technical, where it was included in an article by Jeff Zamek. (Full credit: I adapted this from a recipe by Patricia Griffin, which she adapted from a recipe by Joseph Noble.) The pendants shown were fired to cone 06.

Amy Waller Turquoise Egyptian Paste (Egyptian Faience)
(cone 010 to cone 04)

Flint (Silica) 325 mesh 85
Sodium bicarbonate 6
Kentucky OM #4 ball clay 5.2
Whiting 1.9
Custer feldspar 1.9
Copper oxide 1.0

13 comments:

John Britt said...

Thanks Amy!

mngwa999 said...

Would it be possible to substitute copper carbonate for copper oxide?

John Britt said...

Yes, 1.5% copper carb

John Britt said...

Yes, 1.5% copper carb

Amy Waller said...

You can take 1% copper oxide (or 1.5% copper carbonate) as a starting point. You might want more or less depending on how light or dark you want the color to be. I did a quick look at a collection of recipes for this kind of Egyptian faience (efflorescent, or self-glazing, Egyptian faience) and found a range of .5 - 6.0% copper carbonate and .7 - 3.0% copper oxide.

Paul Wheeler said...

I tried this recipe out! I ended making really dry looking, slightly purpleish white discs... not sure if I did it right.. I'll post pics up later! http://www.sheppertonceramics.com/blog

Paul Wheeler said...

I tried this recipe out a few days ago. I ended up with very dry, slightly purple discs.. I'll upload pictures to my blog - http://www.sheppertonceramics.com/blog

John Britt said...

Probably under-fired. Just try refiring.

Amy Waller said...

Some other things that can affect the glaze formation include:

• how long the pieces dried before firing and what the drying conditions were like

• the size of the pieces (generally speaking, the bigger/thicker the piece, the better the glaze formation)

• how old the paste was (that is, how long before forming the pieces the dry mixture was combined with water)

What cone were they fired to? The source for this recipe fired to cone 09 and 08; I have fired that low with acceptable results. The pendants shown in the photo were fired to cone 06. (I'm not sure where the range of cone 010 to cone 04 came from - that was included in Ceramics Technical but was not provided by me.)

Hope that helps! And thanks for sharing - look forward to the photos on your blog.

Deb W said...

We'll be trying this recipe with three middle school girls this week for their project on Egyptian amulets. At the advice of our local ceramics supply store, we've substituted cobalt stain for the copper for safety. I'll let you know how it works out. Thank you for the recipe and video, it's been very helpful as we've researched this.

Amy Waller said...

Thanks, Deb! Would love to know how it works out.

Jenn said...

Is there a way to do make the faience from home using a stove? I'd like to try and make it but don't understand all these ratios either. Many thanks!

Amy Waller said...

Hi Jenn - a stove doesn’t get hot enough to fire faience. Even if it could get hot enough, I wouldn’t recommend firing faience (or any kind of ceramic) in a stove that is also used to prepare food.

As for the ratios - if you’re talking about the numbers in the recipe (for example, silica 85, sodium bicarbonate 6, etc.), they refer to parts, or percentages, that add up to 100. Any unit of measure can be used for weighing ingredients - grams, ounces, etc. - as long as the same unit of measure is used for all of the ingredients.

So for a 100 gram batch (a good place to start for a first time test batch), each of those numbers would refer to grams:

Flint (Silica) 325 mesh: 85 grams
Sodium bicarbonate: 6 grams
Kentucky OM #4 ball clay: 5.2 grams
Whiting: 1.9 grams
Custer feldspar: 1.9 grams

Total: 100 grams

(The colorant - copper oxide - isn’t included in the base recipe, but would be added with the same unit of measure, so 1 gram of copper oxide in this case.)

Hope that helps!