Potter goes full DIY and makes her own porcelain

The best thing happens: Failure on the third mix!

Super white translucent porcelains are expensive, approaching $200/box in some countries! Even so, variation in properties is common (certainly not good for a "tipping point body" that is difficult to make). The idea of making your own clay body is actually feasible here. Yet Kirsty Kash, maker of this mug, told me that this amount of DIY was something she had never really considered, thinking it would be too complicated without guidance. But ongoing issues with the commercial clay gave her the motivation to give it a try (using a recipe similar to L3778D). She weighed out the materials, slurried up the mix using a propeller mixer, finished by blender mixing and then dewatered on a super-clean plaster bat.

By the third batch, something good happened: The porcelain blistered (tiny bumps on the surface). Subsequent correspondence brought the realization that this type of body is "walking a recipe tightrope" that requires control of the percentage of the key ingredient: Feldspar. It determines the maturity of the fired product. Too much brings blisters, too little and translucency is lost. Simple testing is all that is needed to determine the needed amount. More good news: The change enabled increasing the kaolin percentage by the same amount. That, in turn, enabled reducing the percentage of veegum (reducing the cost).

Her comment a few days ago was inspiring: "I'm getting to know my material so intimately. I have been learning SO much." When I suggested she might end up buying commercial again she responded: "I just bought large bags of all the materials and plan to keep going. I like having the control and being less reliant on the boxed clay. You've converted me!".

Related Pictures

Agglomeration of New Zealand kaolin in both fritware body and glaze

White agglomerate flecking in a porcelain

This picture has its own page with more detail, click here to see it.

White agglomerates of New Zealand kaolin (NZK) have ruined both glaze and body (Zero4 fritware). Both were slurried up by propeller mixing (the latter dewatered on a plaster table). But in both cases, the action of our lab mixer, a very capable device, was not enough to break up the NZK agglomerates! The glaze appears to be the easiest to fix: Sieve it at 100 mesh. But does that really work? No. The particles are 10-20 times smaller than the openings so countless agglomerates could easily remain intact. The body is another matter. It is just about impossible to sieve because it contains significant VeeGum that gels the slurry. However, I am a potter and don't need to make thousands of gallons. Blender mixing is the answer, on high speed, it smashes the agglomerates in seconds. Even for many gallons it is easy to process the slurry in batches using the 2 litre jar of my mixer.

Videos

Links

URLs	https://kirstykashceramics.com/ Kirsty Kash Ceramics Intricately incised porcelain mugs.
Articles	Formulating a Porcelain The principles behind formulating a porcelain are quite simple. You just need to know the purpose of each material, a starting recipe and a testing regimen.

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