*Really* white porcelain slip?

Geographically where are you?

Steve Bath UK

In article , Robert Galejs writes

I'm in the northeast United States. Massachusetts, to be specific.

- Robert

Steve Mills wrote:

What ^ are you firing to? Are you fring China Porcelain or bone china "porcelain" NJ

v

Robert: Since you're in MA, you might try

noticed in their catalog that they are now carying "Southern Ice", abrilliant white clay from Australia. It would be rather easy to make slipfrom that, and it would fire bright white (ox.)I've ordered from them, and found them to be most helpful, and a greatcompany to deal with.Hope that helps, Wayne Seidl

I can fire up to cone 10.

I have no idea of what the difference between china and bone china porcelain. Could you explain the difference?

The porcelain slip I am searching for is to make antique doll reproductions. After firing up to bisque, the doll head will be painted in many passes with china paint, so I don't want to have a glassy surface. In addition, real antique porcelain is very white and all of the hobby porcelains that doll companies sell is quite gray.

Thanks,

Robert

Nancy Alb> What ^ are you firing to? Are you fring China Porcelain or bone china > "porcelain" > NJ

Wayne -

Have you actually made slip out of Southern Ice? An apparently knowledgable Byrne distributor told us that Southern Ice *cannot* be made into a slip. I have no idea of why though. Any ideas?

Thanks,

Robert

Southern Ice is wonderful porcelain and very translucent. They are now also producing Cool Ice, a low fire porcelain, cone 4 to 6. It is very white.

the purest porcelain comes form France.it has the lowest iron content.if you want that level of white you will have to find a supplier of clay from there.

Robert: Sorry to contradict what you've been told, but if they can make a clay from it, YOU can make a slip from it. Mix with water, blend, done. I use a blender. Terra Sig is something else though. I'm having a great deal of trouble making THAT from porcelain. Could just be me... or the fact that most of the particles are the same size, and therefore little to no separation. Wayne

Just use a basic porcelain recipe:

50 Grolleg Kaolin 25 Potash Feldspar 25 Silica

Regards, June

Do you mean Byrne Ceramics from Flanders NJ ? Their clay has a bad reputation but maybe the distributor knows something. I haven't been in my studio because of the cold everything is frozen out there but I'll look up my perfect white cone 10 slip for you tomorrow(SAT) people use it for a white backround on pots or for a porcelain body.

v

There is big difference between casting slip - what I believe Robert is talking about, and decorating slip. It is not that easy to make good casting slip. The greyness of porcelain can be caused by firing in a gas kiln ( even if it is not reduced). Electric kiln gives more white look. I am lucky to be able to purchase casting porcelain from Australian Fine China - a local factory. It has a nice white finish.

Andrea

Yes, I am interested in casting slip. Do you know of any good sources detailing how to make a casting slip?

We have an electric kiln, so that shouldn't be the cause of the greyness.

It's starting to look like no one knows of a semi-local source (northeast US) for actual white porcelain casting slip and I'll have to make my own.

- Robert

A&V wrote:

It is going to be much easier to make your own.

The following are recipes are a starting point for porcelain and bone china

Porcelain is made from 60% china clay, 20% feldspar and 20% quartz,

Fine bone china is 50% bone ash - which adds strength, extra whiteness and translucency - 25% china clay and 25% feldspar.

Plus of course a deflocculant New Zealand China Clays Ltd mine and manufacture the whitest china clay in the world and is marketed as Ultrafine China Clay. It is exported to twenty countries and should be available in the US.

Web site

analysis is

Ca 0.07, Na 0.06, K 0.05, Al 35.8, Si 50.1, Fe 0.28, Ti 0.08, Mg 0.06

As you cab see the impurities ofiron and titania are very small

You may find this link interesting

Two side bars

I have been using a white stoneware clay. In oxidation it is dead white, in reduction it is a non descript grey.

If you make up a porcelain slip you can add toilet paper to make a paper clay. You then can pour it over a plaster or glass surface to get very fine translucent sheets.

Could this be called 'casting' about for information

John W

Robert, Please let us know of the results. I have tried making slip once and made a mess of it. Couldn't deflocculate it properly. I am not saying that to discourage you, quite the contrary, I wouldn't mind trying again and hearing your experience might just push me in the right direction too. Andrea